With their ability to provide high yields of good quality forage and to fix ‘free’ nitrogen from the atmosphere, clovers are finding popularity on many farms. Clovers are combined with grasses to provide leys with both nutritional and environmental benefits. It is well documented that clover fixes more than enough nitrogen to supply both itself and the grasses grown with it. In addition, the inclusion of clover in a ley can raise the protein content of forage by as much as 3%.
The main species of clover used are white, red and alsike. White clover is usually used for long term grazing and red clover for two or three year silage or hay production. Alsike clover can be cut or grazed and is unusual for a legume as it will grow quite acceptably on wet or acidic soils. The establishment of these three important legumes is identical. However, there are some key establishment and management guidelines that need to be applied in order to get the high proportion of clover needed if this type of ley is to be successful.
Establishing Clover Leys
For sound establishment, a well cultivated, firm and level seedbed is essential.
Clovers have small seeds and they will not grow satisfactorily unless they
are sown at a uniformly shallow depth of around 10mm. Clover seedlings are
not competitive once they have emerged and it is at this stage that weeds
may need to be controlled. This can be done by topping or using a ‘clover-safe’
herbicide, although these can check clover growth to some degree.
Clover leys can be sown in the spring or autumn. To germinate, clover seed needs a soil temperature in excess of 6 degrees centigrade. This is usually reached in mid March. Spring sown clover usually establishes well and seed mixtures can be undersown to cereals. Sowing rates of spring cereal should be reduced by one third otherwise the undersown ley may be smothered. Alternatively clover/grass mixtures can be direct sown. When sowing in the autumn, clover seedlings can be vulnerable to slugs and weevil damage. It is therefore essential to sow by mid September to ensure fast establishment.
Once sown it is vital to consolidate the seedbed by rolling. This is important because the roller presses the seed into intimate contact with soil particles which leads to a faster transfer of soil moisture to the seed and ultimately faster germination and establishment.
Provided the sward contains 30-40% clover there is little need to apply artificial nitrogen fertiliser. To achieve this high clover content the seed mixture will need to contain 1.5 kg of white or alsike clover or around 3 kg of red clover per acre. Grasses should be included at around 10 kg per acre; any higher and they may smother the clovers as they are more competitive as seedlings.
Over-Seeding Existing Pasture
Techniques have been developed to introduce clover into existing pasture and
there are many situations where this is advantageous. For example, in permanent
pasture systems the prospect of ploughing and reseeding may not be welcomed
in order to add clover to the sward. However, white clover seed (with its
grazing potential) can be oversown into existing pasture with little interruption
to grazing management. The key is to tightly graze before sowing, graze again
4-5 weeks after sowing and avoid cutting for hay or silage for the rest of
the season. Sowing should be avoided during May and June when grass growth
is usually too competitive to allow the clover to establish. The seed should
be surface sown with a grass seed drill or broadcast. It is often beneficial
to harrow before sowing to open up the sward. There needs to be an adequate
supply of soil moisture and should there be any phosphate or potash deficiencies,
then these need correcting before sowing.
White clover seed should be sown at 2 kg per acre. Medium or small leaved varieties are recommended and it is usual to use at least two varieties. The cost is likely to be in the region of £15 per acre.
Finally, it is not surprising that more farmers are rediscovering
the benefits of using clover leys. These plants are valuable to all farmers
as they produce good quality forage that ruminants enjoy eating and more importantly
they do it very cheaply.
For further information Ian Wilkinson can be contacted
on 01608 652552 or email ian@cotswoldseeds.com
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Cocksfoot
- The Black Sheep of the Grass Family?
This article considers whether farmers should grow
cocksfoot (Dactylis glomerata) on dry soils as an alternative to ryegrass.
Ian Wilkinson, Managing Director of Cotswold Seeds explains why, as we enter
a new agricultural era, we need to reconsider grasses such as cocksfoot.
Given the difficult times many farmers are facing, the time is ripe to rethink
the various forage crop possibilities. For the majority of milk and meat producers
it has become necessary to find methods of production which are efficient,
cheaper and sustainable. A more extensive farming system is becoming popular,
which concentrates on utilizing grazed grass. The reason is simple. Grazed
grass is by far the cheapest forage available and this resource needs fully
exploiting.
Most sowings to grass are ryegrass based. You could be forgiven for thinking
that all UK grass is ryegrass. You wouldn't be far wrong. Every year some
12,000 tonnes of ryegrass seed is sown here. Compare this with the miniscule
sales of other forage grass species such as cocksfoot, timothy and fescue
and it's easy to see why ryegrass gets all the attention.
However, there are some farms where ryegrass is not the right choice and an
alternative would be better employed. Cocksfoot is a good example of an alternative
species as it is significantly different to ryegrass and offers a range of
benefits but does have some disadvantages.
The Great Historical Debate
Unlike the other more modest members of the grass family cocksfoot has always
sparked much debate from agriculturalists. Since its introduction from North
America in 1763, Orchard grass as it was formerly known, has made many friends
but has nearly as many foes. The reports from England in the eighteenth century
make interesting reading. They start with Bartholomew Rocque who on being
given cocksfoot seed by the then Committee of Agriculture in London wrote
two years later 'very coarse, but very sweet and of great growth'. W. Sole
however, condemned cocksfoot and wrote a scathing report in his 1799 account
of the principle English grasses, saying 'that it was refused by all cattle!'
There were many other references some years later when the species became
more widely grown. More positively, A. Young, in his account of Norfolk Agriculture
in 1804 said 'cocksfoot provided sheep with a palatable feed which did not
burn up in the severe drought of 1800.' G. Turner in his Agriculture of Gloucestershire
said, 'cocksfoot springs directly after the sythe in mowing grounds…and
from the stock lying on it and paring it down it seems very palatable to them.
Later accounts from seed merchants M J Sutton and J Hunter, began to emphasize
that the more positive results were coming from cocksfoot based leys which
received 'proper' management.
It must be remembered that these accounts were opinions that were often many
times removed from the initial field observation by the farmer. They certainly
did not benefit from the scientific data we have become used to in more recent
times. The most relevant accounts of cocksfoot leys were from R H Elliot who
pioneered the Clifton Park farming system and W Lamin who wrote his account
of thirty years of growing cocksfoot based leys in 1943. Both these men appreciated
the benefits of cocksfoot. They realised that its deep, penetrating roots
not only provided forage during dry times but also improved the soil by increasing
the humus content. This was of great importance, particularly to Lamin who
farmed on drought prone, sand land in Nottinghamshire. They sowed quite complex
seed mixtures that contained other deep rooting grasses, herbs and clovers.
They omitted ryegrass. The results proved to be better than ryegrass leys
and helped promote the use of cocksfoot.
However, at around the same time the widespread introduction and use of artificial
nitrogen fertilizer led to ryegrass becoming the UK's favorite. Not surprising,
as ryegrass responds better to the application of artificial nitrogen than
any other grass - soil moisture allowing.
Today, with an increased cost of fertilizer and a decreased price for milk
and meat products there is an urgent need to lower the cost of production.
One way to do this is to grow forage less intensively, reducing nitrogen fertilizer
inputs and thus opening the door for the alternative grass species.
Will Cocksfoot provide Quantity and
Quality Forage?
The value of any grass to the animal depends on how much of it is eaten and
what it contains. As a grazing grass cocksfoot is quite palatable when young
and has a D-value similar to ryegrass. Palatability falls as the grass matures
and for this reason it is important not to undergraze cocksfoot leys once
established. It is fair to deduce that cocksfoot is better suited to grazing
as it is inclined to become clumpy if left to mature too long for silage or
hay production. This clumping habit can make the grass less palatable but
usually takes place over the medium term and therefore cocksfoot leys are
best grown for three or four years only.
A three year research programme at The Rowett Institute in the late 1960's
compared dairy cow performance on pure stands of cocksfoot and ryegrass. The
results showed little difference in milk yield or milk composition. There
was no difference in the liveweight changes of the cows. Both species received
high levels of artificial nitrogen fertilizer. Perhaps due to this, the ryegrass
yield was higher. Overall grass yield was the main difference between the
two species. What though would the results have been if lower levels of N
had been used or the experiment had taken place on dry land?
With low/moderate inputs of artificial nitrogen cocksfoot will yield almost
as much as ryegrass. Yields of ryegrass increase as artificial nitrogen is
increased subject to soil moisture being available. On dry soils, ryegrass
yields can be disappointing and will not be increased if high levels of nitrogen
are applied.
The Place for Cocksfoot
Cocksfoot will grow on soils ranging from the lightest sands to wet clays
but the place to fully exploit its potential is on drought prone land. When
used in conjunction with other forage grasses and clovers it can make a wonderful
sward. Cocksfoot grows early in the spring providing an early bite and it
is the quickest grass to recover afterwards. Walking across a previously grazed
field, its presence can be observed by virtue of its leaf shooting ahead of
its competition. In summer drought it excels especially when grown with drought
resistant legumes such as red and white clover.
The Soil Benefits
For the past fifty years or so our concentration has been focused on what
develops above ground rather than what goes on below the surface. Effort spent
improving topsoil and subsoil correlation with deep rooting varieties of plants
and herbs will improve all soils.
Plant roots that penetrate to a great depth vastly increase the 'natural plumbing'
of the land. This allows both water and air to move deeper into the ground,
reducing surface saturation and speeding drying time. It also allows the surface
soil temperature to increase at a quicker rate and therefore faster recovery
and establishment of grassland is made possible. Creating a soil profile with
an increased water holding capacity can not only help to reduce run off and
lessen the effect of flooding but it can also provide a valuable reserve of
moisture in a drier time.
Tap Roots - Deep Soil
Tap roots allow a passage for air to reach deep into the subsoil increasing
the lung capacity of the earth. As the water table rises and falls throughout
the year, by virtue of atmospheric pressure, the ground expels and inhales
fresh air. This freedom of air movement through the soil is of paramount importance
to the leguminous plants, which are often grown with cocksfoot. Nitrogen is
absorbed through the roots of the legume into the nodules where rhizobium
bacteria convert it into soluble plant food. Constriction of aeration can
greatly impede the growth of legumes and reduce the production of soluble
nitrogen. This lung action also supplies oxygen to the micro-organisms that
break the organic matter down into humus, sustaining the conversion of dead
plant and animal matter into available plant food. Marvelous, natural chemistry!
Although there is little scientific evidence, there is much made of a deep
rooting plants ability to unlock and draw minerals and vitamins from the soil.
These elements are beyond the reach of the shallow rooted ryegrasses, but
for cocksfoot and deep rooting herbs it is possible to transfer these to the
surface where they can be consumed by the grazing animal.
How much Cocksfoot?
Cocksfoot should be included in seeds mixtures at between 3 and 6 kilos per
acre. (7.5 - 15 kg per hectare.) It is unusual to grow cocksfoot as a pure
stand. It is more often added to a ryegrass/timothy/white clover ley at around
3 kilos per acre, in lieu of some of the ryegrass. This is a compromised mixture,
some would say, providing neither one thing or the other.
It would be much more exciting to reduce the ryegrass or leave it out altogether.
Mr J R Hargreaves in Nottinghamshire does just this. For some years now Hargreaves
has grown cocksfoot leys with little or no ryegrass. He has light gravel land
and is in a low rainfall area.
The farm comprises of a Friesian dairy herd, a sheep flock and arable. The
cocksfoot leys are used for the production of silage for milking cows and
also late autumn/winter grazing for the sheep. They are sown for four years.
The reason cocksfoot leys are grown at Thorpe Fields Farm is to guarantee
production of grass through the spring and summer. It is usual to take a first
cut of silage in the first or second week of May followed by a second and
often a third cut. 'On my light land,' Hargreaves says, 'ryegrass just runs
to seed and has no bottom. The second and third cut of cocksfoot however just
keeps producing leaf providing it is cut frequently. There are no problems
with bloat, which is surprising given the amount of clover we grow with it'.
Leys are usually sown after winter barley and consist of cocksfoot, white
clover, red clover, burnet and chicory. Occasionally a small quantity of Italian
ryegrass is added as a cover crop to boost yields in the first year of production.
However, if they run to seed they have a nasty habit of reappearing as weeds
in the arable rotation.
The arable crops are also helped from the preceding leys according to Mr Hargreaves.
He states 'the crops which follow the cocksfoot leys benefit from the decaying
roots which are ploughed in as a soil improver. This has the effect of increasing
the soils ability to hold moisture.'
Hargreaves has based his farming system around Lamins ideas. A typical mixture
as used by Lamin is detailed below and today would cost around £40 -
£50 per acre. ‘Lamins’ Deep Rooting Seed Mixture
6.00 kg cocksfoot
2.50 kg meadow fescue
1.50 kg timothy
1.00 kg red clover
1.00 kg white clover
0.50 kg chicory
0.25 kg burnet
0.10 kg ribgrass
0.05 kg yarrow
0.10 kg sheeps parsley
13.00 kg per acre
To establish such a mixture it is essential to prepare a well-worked seedbed,
as some of the seeds in this type of mixture are quite small. Broadcasting
followed by a light harrow and heavy roll should spread the seed evenly and
leave the seed near the surface.
The other important factor to consider is time of sowing. Unlike ryegrass
mixtures, which tend to forgive late sowing, the cocksfoot ley should be sown
by late August. Later sowings are vulnerable to weed competition and are best
avoided.
Summary
It seems strange that the majority farmers in the UK have shunned alternative
species such as cocksfoot when there are so many benefits to be obtained.
Nevertheless, ryegrass is reliable and on farms where rainfall can be relied
upon throughout the growing season it is likely to remain the species of choice,
but elsewhere, alternative grasses could well find a new home. So, perhaps
cocksfoot is not so much a black sheep - more a dark horse.
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The Three R’s
- Give Your Seeds the Best Start in Life
The late Robert Handy who farmed land at Andoversford,
near Cheltenham always said that there were three golden rules to observe
when sowing grass seeds.
1. Roll,
2. Roll,
3. and Roll again!
This is essential advice for anyone about to sow grass leys or small seeds.
Intimate not Intermittent Contact
Placing small seeds in a cloddy or loose seedbed often results in failure.
The objective when preparing a seedbed is to produce a fine, firm tilth which
will enable the sown seeds to be in intimate contact with the soil particles.
The close proximity of the seeds to the soil will allow the movement of soil
moisture to the seed - a prerequisite for germination.
Seedbed Preparation
Correctly timed cultivations are essential to produce a good seedbed. Soil
that is either too wet or too dry will not submit to the most expensive cultivation
machinery.
Once ploughed, or in the case of minimal cultivations, the seedbed should
be worked from the top down. This ensures that clods are not brought to the
surface where they will become difficult to break down. It is better to be
patient and wait until soil conditions are right for cultivation rather than
rush in an attempt to beat the weather. Later sown crops in better seedbeds,
particulary in the spring, frequently show more vigour and suffer less with
weeds and pests.
In addition to producing a fine seedbed the surface needs to be level. This
is of particular importance where a drill is to be used for sowing.
Drill or Broadcast?
Whether This is a simple matter of preference. Drilling usually ensures a
consistent depth of placement which in the case of grass leys should be 10-15mm.
This consistent depth is an advantage to the crop but the sowing depth will
only remain consistant on a level surface. It is generally recommended that
grass seed mixtures should be crossed drilled. The reason for this is to cover
as much of the soil surface as possible to leave as little room for weeds.
Broadcasting has the benefit of distributing seed more evenly so the emerging
seedlings are more evenly spaced allowing the slower growing species such
as white clover more chance of establishing. Drilling has the opposite effect
of placing seeds more tightly together in rows which can lead to the strongr
and shorter term species dominating. Effectively this means that longer term
leys which oftern include more species should be broadcast.
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Sainfoin - Nomenclature and History
There is a record of sainfoin being imported into England from France in 1652. From this time onwards it became widely grown in certain areas mainly the Cotswolds, Salisbury plain and parts of East Anglia. It was grown for sheep, cattle and horses. This was before the use of artificial fertilisers and there is little doubt that the crop is largely self sufficient except that potash needs to be available. This was often obtained from farmyard manure or wood or coal ash.It was considered a vital cog in the farming rotation of those days and was known as a good preparation for ensuing crops. Some tenancy agreements stipulated that an acreage of sainfoin must be maintained. By 1800 in Oxfordshire it was grown on about 10% of the acreage in that county.
From around 1960 onwards the acreage declined rapidly as did the area of red clover and other leguminous crops. This was due to the advent of cheap nitrogen fertilisers and the extensive use of the newly developed bred strains of rygrasses. Legumes were considered out of date. Intensive farming was in vogue, strongly promoted by the fertiliser manufacturers.
The last few years have seen a swing back into more traditional methods. There is now a strong demand for "organic" food and artificial nitrates were found to be polluting the water supplies. Red clover is once more a very popular crop in the UK with longer duration varieties being available and the need to fix nitrogen on lower input systems. It would seem that the time is ripe for sainfoin also to make a comeback.
There are some 130 different Eurasian species of
Onobrychis (from Greek "donkey fodder") but the main cultivated
species is Onobrychis viciifolia Scop.
Some Sainfoin Facts
SAINFOIN (Wholesome Hay)
(Onobrychis viciifolia)
Common sainfoin: Duration 5 Years or more. English Origin
Giant sainfoin: Duration 1-2 Years. Continental Origin
Hybrids of above.
Cultivars or bred strains which have been available to us so far include Nova
(Canadion), Emyr (English), Perly (Swiss), a variety from China and some American
bred varieties
Other Sainfoins;
Mountain Sainfoin - Onobrychis montana
Alpine Sainfoin - Hedysarum hedysaroides (Alpine meadows)
Italian Sainfoin - Hedysarum coronarium (Grown in Sicily)
Small Italian Sainfoin - Hedysarum glomeratum
Genetic resources 100 species - mostly tetraploids
The name sainfoin is from French meaning "healthy
hay" also Latin Sanum Foenum. In England it was sometimes wrongly called
Sainte Foine and thence "holy hay". It was known that animals fed
on sainfoin were more healthy and put on weight more rapidly than on other
forage
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We have research information from the following countries;Canada, USA, England, Switzerland, Russia, Poland, Bulgaria, Turkey, France, Romania and Armenia.
We have not had much contact with the southern hemisphere however and would like to hear from all countries about their experiences with sainfoin..We would welcome contact with anyone who has worked with the species
Please e-mail: robin@cotswoldseeds.com
The fact that it has been grown in Canada and the former Soviet Union indicate that the crop is very winter hardy as well as drought resistant.
In the UK sainfoin was grown mainly in the southern half of England where the soil type suited it, e.g. free draining chalk or limestone areas, also sandy soils around Newmarket. This gave rise to local strains some of which are still available.
Formerly, two types of sainfoin were recognised, "Giant" sainfoin, lasting 1.5 - 2 yrs (also known as Single Cut) and "Common" sanfoin, lasting up to 7 yrs (also known as Double Cut).
To my knowledge, there is no Giant seed available
in Europe, nor can I see the advantage of growing it.
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Sainfoin leys should be considered to last 4 years or more. In this they are similar to Lucerne. However a proportion of the sainfoin will last considerably longer. (up to 20 years) The potential longevity is confirmed by its presence in self sown patches which recur annually e.g at side of roads etc. As a crop it will become diluted by grass after about 4 years.
Establishment;
The seed of sainfoin is quite large (5 –
7 mm.) being contained in a husk. Formerly milled seed was also used but not
in recent years.
In the UK sowing is usually done in spring after
the soil has had time to warm up (April or May) or it can be sown later up
to August. A high seed rate is required on account of the large seeds in the
husk. Recommended rate 65 – 100 kg. unmilled seed per hectare. (25 –
40 kg. per acre) The seed rate will depend on germination level of seed, size
of seed and soil conditions.
A companion grass such as meadow fescue should
be sown @ 7.5 kg. per hectare (3 kg. per acre ref. Henry Edmunds). In recent
NIAB trials this was found to be the best species of grass under UK conditions.
Other grass species such as cocksfoot (orchard grass), timothy or tall fescue
may be suitable.
Sowing The Crop
Seed Rate - 25kg per acre ( 82kg per Hectare)
Depth of Sowing 1-2 cm
Plant Density Required
70 - 150 plants per sq. metre at establishment
50 - 60 plants per sq. metre at the end of the first season
Companion Grasses - Must
be non-competitive
Meadow Fescue 5 - 7 kg per hectare (preferred)
or
Timothy 2.5 kg per hectare
White Clover 0.5 - 1 kg per hectare
Sainfoin can be sown into a spring barley cover crop. This provides a return in the first season. The barley seed rate is reduced and the seed bed should be very firm and fine. The sainfoin is cross drilled into the barley.
DEPTH OF SOWING 1 –2 cm.
Sainfoin must be allowed to grow unchecked during the summer of establishment and grazing, if any in the autumn should be light according to the crop or it should not be grazed at all (ref. Dai Barling).
At emergence the crop can be treated with a suitable selective weed killer if necessary. Weed control is however best achieved by the "false seedbed" i.e allowing the weeds to grow and then harrowing in before sowing. On a pure stand of sainfoin grass weeds can be controlled in the dormant period.
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Trials in the UK, Seeds and Varieties
Recent trials at The Royal Agricultural College, Cirencester (Gloucestershire) and by the National Institute of Agricultural Botany (Hampshire) have indicated the higher yield potential of sainfoin. At Cirencester, yield from four cultivars were from 7.16 tonnes DM/hectare (Nova) – 9.23 tonnes DM/hectare (Cotswold Common).
At NIAB (harvest years 2000 & 2001)the best yields were from an association of Emyr with meadow fescue @ 14.52 and 14.44 tonnes DM/hectare. The traditional variety Cotswold Common yielded as a pure stand 14.04 and 14.17 tonnes DM/hectare. Four cuts were taken each year.
For details of trial results, e-mail:
jason.koivisto@royagcol.ac.uk
or
steven.bentley@niab.com
Varieties
We have been restricted so far to the following:
Cotswold Common,
Hampshire Common,
Nova,
Emyr,
Perly,
Somborne
and an unnamed Esparcette from Ukraine.
We want to find new varieties from other sources.
Lucerne - A crop with a Future
Foreword
Studies have shown that the inclusion of Lucerne
silage in dairy cow diets can improve forage intake, and increase output of
milk protein, with no change in milk fat. The benefits together with lower
forage production costs when compared with grass silage should help to improve
margin/litre of milk produced. Yet in spite of all of these important attributes,
ruminant livestock producers have been reluctant to grow Lucerne silage and
the area in the UK is at present small. The reasons are that in general forage
legumes are perceived as crops that are currently difficult to grow and hard
to conserve. This situation is changing with the availability of suitable
disease resistant varieties, the arrival of new equipment designed specifically
for rapid wilting and access to big balers, the use of appropriate additives
for effective fermentation and the production of advisory leaflets such as
this one from Cotswold Seeds.
All these factors have helped to renew interest in forage legumes and will increase the knowledge and experience of a crop with a future.
PRINTABLE VERSION Lucerne - A Practical Guide
Lucerne - A Premier Forage
Legume for home grown PROTEIN
Lucerne or alfalfa (Medicago sativa) is a legume that has been cultivated
for around 2,000 years. It grows best in areas of high sunshine. There are
1 million hectares in France and about 12 million hectares in the USA. There
is therefore a wealth of research information available on the crop.
Lucerne is tolerant of the winter temperatures experienced in England and
Wales and has been grown successfully in all the arable cropping regions,
but only on the right type of soils. It is a deep rooting crop which can sustain
dry matter production at times of low rainfall.We must expect rising temperatures
due to climate change and drought conditions are likely in the future.
So why grow Lucerne?
There are five main reasons for growing Lucerne:
1. This mainly cutting forage crop will give regularity
of yield. THIS IS ITS TRUMP CARD. In a dry summer it will do better than either
ryegrasses or forage maize.
2. It gives a very high DM yield comparable to that of Italian ryegrass but
will persist for four years.
3. It is a HIGH PROTEIN crop. According to growth stage the protein content
ranges from 15% - 20%.
4. It is an excellent cutting crop and is complementary to forage maize.
5. It is rich in vitamins and minerals, and if cut at the right stage is low
in fibre and high in energy.
Utilisation
In the UK Lucerne is best made into silage for milk production. It can also
be fed green to cattle when other fodder is not available.
For HAY MAKING it is excellent given suitable weather conditions. The hay
is very popular for horses, and indeed it is often imported from America for
this purpose on account of the high quality of the product. Lucerne hay can
also be fed to beef or dairy cattle with spectacular results.
A further specialist use is for drying when it is made into high protein meal
or pellets. Dried Lucerne pellets have a high carotene content, are high in
energy and with a protein of up to 20% are a valuable feed for cattle, sheep
and young stock.
Further benefits from growing Lucerne derive from its remarkable tap root
system. The roots are known to penetrate to a depth of 3 metres thus enabling
the plant to draw moisture and minerals from a considerable depth. The breakdown
of these roots contributes to the fertility of the soil by increasing the
humus content, assisting in drainage, and also contributing residual nitrogen.
Thus there is a benefit to the following crop. Nitrate leaching is also reduced
as the plants take up a large amount of water during growth thus reducing
run-off. (ref INRA)
Establishing Lucerne
The crop requires careful management, but if the guidelines are followed there
is nothing difficult about it.
Field Choice
The choice of field is important. For root nodulation to take place, the pH
must be in the region 6.2 - 7.8 and to a reasonable depth. (a minimum pH of
6.0
to a depth of 1.5 metres is suggested). Also the field must never become waterlogged
as this will kill off the Lucerne. The range of suitable soil types is considerable
from clay loam to a light chalk or limestone and it is on the latter that
Lucerne has been usually grown. Heavier soils should not be ruled out provided
that they are deep and permeable with an adequate supply of moisture during
the growing season. The crop is very sensitive to poor drainage and compacted
soil conditions that restrict root growth, nor will it tolerate acid soils.
Sowing Time
It is advisable to sow either in spring or summer, when the soil has warmed
up.
Late autumn sowing is risky as the seedlings being slow growing at first do
not have time to develop before the onset of winter. For summer sowings it
is recommended to sow after an early harvested cereal such as winter barley.
The end of July or beginning of August are the latest dates for sowing provided
there is sufficient moisture available.
Under sowing Spring Cereals
This has been a satisfactory method in the past and is still popular. Priority
has to be given to the Lucerne and the cereal removed as soon as possible.
If the cereal, usually spring barley, is cut as silage at the milky stage
this provides a conservation crop in a year of establishment. A low seed rate
of about 50% of normal is advised for the cover crop, Drilling without a cover
crop into a 'stale' seed bed, well-prepared to a fine tilth is satisfactory
but it is usually necessary to spray out weeds which may become very competitive
while the crop is becoming established.
Direct Sowing
There is cost in terms of loss of production in the first year, when only
2 cuts will be obtained yielding 20 to 40% of normal, but this is a SURE way
of establishing a successful ley. It also enables a dressing of farmyard manure
or slurry before sowing to reduce the need for seedbed fertilizer, and a ”false”
seedbed can be used to reduce herbicide requirements. It should be remembered
that a pure stand of Lucerne can be kept down for many years.
Protection of the crop
During Establishment:
Seedlings emerge within 1 - 2 weeks of sowing.
Weeds grow quickly and should be sprayed with 2.4-DBas soon as the Lucerne
seedlings reach the stage of having three trifoliate leaves, this will normally
be about 4 - 6 weeds after
the sowing date depending on the weather. Slugs can also be a problem. Traps
can be set to find out the number present or otherwise some slug pellets can
be put down as prevention. Use 2,
Established Lucerne:
A pure stand of Lucerne can be treated with a herbicide such as Carbetamix
each winter during the dormant stage of the crop. This will eliminate grass
weeds and keep the crop productive.
Mixtures of Grass & Lucerne
There are several advantages in growing a mixture, but it is necessary to
obtain the right balance between the species. The total yield is likely to
be higher. If silage is the objective, as it is for most growers, the grasses
present will make it is easier to obtain a good fermentation supplying soluble
sugars which are needed. The first cut will also be bigger when grasses are
present as they start growing in advance of the Lucerne.On ORGANIC farms,
the advantage of a mixture with grasses is that the extra competition will
discourage weeds.
If on the other hand the objective is HAY then it is better to grow a pure
stand. This will enable the field to be kept free of grass weeds by using
chemical weed control.
Which are the best grasses?
In the UK we have favored meadow fescue and timothy as companions. These are
non-competitive grasses. A low seed rate of 3 kgs per acre for meadow fescue
or 1 kg per acre for timothy is used. The grass seeds should either be shallow
drilled or broadcast after the Lucerne has been drilled. Cocksfoot can also
be used for its drought resistance.
Trials in France over three years using late Cocksfoot have shown that such
a mixture can be used for grazing by sheep.
Bloat
The risk of bloat when cattle are grazed is however very real and we are therefore
not able to recommend grazing Lucerne other than at the very end of the growing
season. The methods of controlling the bloat have often been troublesome,
expensive and only partly effective.
The Seed
The seed of Lucerne is a small one about l/l0th the size of wheat grain. Use
a seed rate of 8 kgs per acre to avoid risk of poor establishment. The seed
must be treated with a culture just before sowing. The culture consists of
a live inoculum of Rhizobia meliloti. This is essential to promote effective
nodulation on the roots. It is easy to do, inexpensive and should always be
used. The depth of sowing for the Lucerne should be 1 - 2 cm and the seedbed
must be fine enough to allow good contact between the seed and the soil. If
a companion grass is to be sown then this should be cross drilled or broadcast.
It is not recommended to sow the seeds mixed.
Varietal Choice
There is a huge selection of varieties to choose from. Much of the plant breeding
has concentrated on the US and southern European markets. It is however essential
to grow a suitable variety for UK conditions, this means one that is winter
hardy and resistant to disease, particularly Wilt.
We recommend the following variety;
Vela
Seed stocks may become limited but efforts will be made to ensure continued
supplies.
Seed Cost
Lucerne
4 Year Cutting Crop
8.0 kg certified VELA Lucerne
46.40 per acre
Grass Option
3.0 kg certified LIFELIX meadow fescue
1.0 kg certified ERECTA timothy
£10.34 per acre
Culture
1 Sachet per 25 kgs of Lucerne Seed (Treats 3 acres) £8.00 +
VAT
Fertiliser
Establishment:
When sown under a cover crop use the normal fertiliser programme for the cereal
unless P and K levels are low, but do not apply too much N on account of the
risk of lodging.
For Lucerne sown as a pure stand no nitrogen is necessary unless following
a succession of cereal crops when 25 kg N per hectare should be used. P and
K requirements are high and rates of application should relate to the soil
analysis (see table below).
Production:
A well established Lucerne crop will not require further nitrogen. The phosphorous
and potassium requirements are higher than those for grass and need to be
met in order to maintain yields. Soil should be analysed every three years
to assess the correct amounts needed. It should be noted that 1 tonne of Lucerne
dry matter removes 29 kg/ha potash and 7 kg/ha phosphate.
Management of the Growing Crop
In the establishment year, avoid severe defoliation at all times. Cut spring
sown crops in mid-August to allow adequate recovery before winter. Leave summer
sowings unmown till November when mowing should be timed to be just before
winter die-back. Undersown crops should be left to grow into the winter. Crops
with a companion grass may be grazed lightly with sheep in the winter.
Recommended rate of Nutrients (kg/ha) for
establishment and production per cut:
Established Lucerne can be weakened by too frequent defoliation. The crop
should be allowed to reach a good bulk before cutting. Harvesting at the first
flower bud stage gives the best compromise in terms of yield and quality.
The quality falls rapidly as the flowers open. First cut will usually be about
mid May and this gives time for three subsequent cuts during the season.
Autumn management is important for plant persistence. The plants must be allowed
to build up their root reserves, and this means that the last cut must take
place 6 weeks before the estimated end of the growing period (end of October).
After this the crop can be either cut or grazed, but the feeding value may
be low. It may be preferable to let it die back during the winter.
Lucerne Silage
The principles of making Lucerne silage are the same as those for other crops
such as grass or maize. However Lucerne is high in protein and low in soluble
carbohydrates which are needed to enable anaerobic bacteria to produce lactic,
acetic and propionic acids which preserve the forage as silage, these acids
reduce the pH and inhibit further bacterial and enzyme action. The process
takes about 6 weeks.
The most critical time is during the first few hours of storage. Long exposure
to air may result in the disappearance of much of the available carbohydrate
and results in deterioration of the plant material. Undesirable bacteria (Clostridium)
can grow under high pH and result in a butyric acid fermentation which makes
the forage very unpalatable. Badly fermented Lucerne silage is a total disaster
and it is therefore essential to use an approved additive as well as allowing
the crop to wilt. Care should be taken when handling the wilted material to
avoid loss of leaf.
Moisture content
This should be less than 65% for successful silage making. An evaluation can
be made by squeezing or ringing out the moisture in a handful of the forage.
There should be no free juice apparent.
Additives
There are many products on the market - seek advice from your supplier.
A typical analysis of well-fermented Lucerne silage is dry matter 280g per
kg, crude protein 200g per kg, D value 60 and ME 9.7 MJ.
Round bales are commonly used as a method of conservation. The wrapping needs
to be thick enough to prevent the stems of the Lucerne puncturing the plastic.
Bales are more adaptable than clamp silage and have significantly improved
the potential for Lucerne.
Spray Materials for Lucerne
Dicotyledon weeds: 2,4 - DB, Carbetamex, Gramoxone (off Label), Kerb.
Annual grasses: Carbetamex, Hoegrass, Kerb.
Please check with your supplier for detailed recommendations as these are
continually changing.
Acknowledgements
Information on Lucerne has been from the following sources:
Forage Legumes Group
ADAS
La Luzerne. GNIS, INRA, ITEB.
David B Hannaway, Oregon State University.
Bruce Whithead B.S.c (Hons) Lucerne Thesis.
X Charrier INRA, Lusignan
- By Ian Wilknson and Robin Hill of Cotswold SeedsPRINTABLE VERSION
Overseeding - Renaissance of a Simple System
Never in recent memory has it become more important to find a way to make livestock farming more profitable. Forage Matters considers this problem and suggests that a lower cost of forage production will increase farm margins There appears to be little that an individual farmer can do about the price paid for livestock products given the way in which these products have become subjected to price pressures from cheap imports and a fall in demand from the consumer. Nevertheless, a way forward must be found by farmers to preserve an economic and healthy livestock industry.
A more extensive farming system with lower inputs is
widely predicted. Growing lower cost forage will reduce the cost of production.
For such a system to be successful it will need to provide much of its own
protein and nitrogen. This will have the immediate effect of reducing variable
cost expenditure by reducing bought in feed and fertilizer. Ultimately this
will lead to increased gross margins arid healthy profit and loss accounts.
Fine words we hear you say, but how can this be done?
The Answer
The way to lower forage production costs is to fully
utilise legumes such as clovers and to graze as much as possible. Legumes
have become less popular in recent years as fertiliser use has increased.
However, legumes could still supply more than enough nitrogen for most systems
if they were called upon to do so. Legumes are also an excellent source of
protein for the ruminant animal.
Our research scientists have been evaluating methods of using legumes for forage for many years. Most of this work has concentrated on white clover. Work at the Scottish Agricultural Colleges and the Institute of Grassland and Environmental Research has time and again demonstrated that more extensive clover based farming systems can be profitable. Many farms have vet to take advantage of this information, preferring instead to continue growing mono-crops of rye- grass and extensively using artificial nitrogen. Now difficult financial circumstances focus our minds on the need for change.
Sources of Protein
In the UK about 85 per cent of ruminant protein
from homegrown crops is from grass. Most of this is in the form of grazed
grass as opposed to grass silage. The various alternative crops such as maize
cereals and peas make only a trivial contribution and it is unlikely that
new protein crops will become available. In the light of this it becomes obvious
that we should concentrate on how grass based leys could be enhanced to pro-
duce more protein. Improving the quality of grazing and grass silage is likely
to be the best way of increasing profitability in the immediate future.
The use of grass leys containing legumes will increase the quality of forage and the intake of material by the animal. Ruminants will consume 20-30 per cent more forage when offered legume forage compared with pure grass and this is not the whole story as the available protein in legume silage is much greater. Losses in ensiled grass leave only 40 per cent available protein, the rest being degraded to ammonia and amino acids, but with a well fermented legume silage the amount of protein left is 60 per cent.
Growing Protein Legumes
Legumes can be sown with ryegrass leys. White clover
is generally suit- able for grazing although can also be grown for silage.
The more productive, but shorter-lived red clover is better adapted for silage.
Both of these species can be introduced by over-seeding into existing swards
but are better if sown at the time of re-seeding.
The objective with both red and white clover is to establish between 20-35 per cent in the sward. This level is adequate and will lift protein content by around 3-4 per cent. John Bax at SAC Crichton Royal Farm an a classic research programme showed that grazed grass/white clover cost £12/t whereas grazed grass without clover, but with nitrogen fertilizer cost £18/t of dry matter.
There are also large legumes such as Lucerne and Sainfoin, which can also provide protein. These are specialised crops that have potential on free draining soils. These are generally grown as pure stands and also have low input requirements.
Free Nitrogen Here
Would you put petrol in your car if it were possible
to run it on air? All forage crops depend on the availability of nitrogen
in the soil to promote growth. The use of legumes provides free nitrogen by
a unique ability to fix this from the air via their root nodules. Clovers
can sup- ply over 200 kg of N per hectare. This is more than enough nitrogen
for most farming systems. It is very easy to justify legumes at this time
with artificial nitrogen fertilizer prices being inextricably linked to the
price of oil.
Legumes are also more drought resistant than ryegrass and have the added advantage
of improving the soil on which they grown. They are generally deeper rooting
and when ploughed in leave the soil in good heart' for the following crop.
Addressing Problems
It is a recognised characteristic, particularly
of white clover, that spring growth is slower than grass plus nitrogen fertilizer.
This difference will be influenced by the season, with little difference in
years with a mild spring. Over an eight year period the difference in turnout
date on SAC'S Acrehead system was only 2.4 days later on grass/white clover
swards. If it was felt that earlier growth was required, tactical applications
of nitrogen fertilizer could be applied. Provided that this was limited the
subsequent clover growth would be unaffected, particularly with the newer
more nitrogen tolerant clover varieties. Alternatively, an area of ryegrass
plus nitrogen fertilizer could be maintained for earlier spring growth.
Often comments are made that clover is included in seeds mixture but that it doesn't last. There can be many reasons for this but the most common fault is the selection of the wrong variety for the system. Also it is counter productive to apply high levels of nitrogen fertilizer and then bulk up for silage. This has the effect of quickly depressing the clover con- tent and the nitrogen fixation benefits are lost.
Weed control is another reason cited for not including
clover in leys. There is no simple solution to this. However, clover safe
herbicides are available, though these need applying when weeds are small
to be effective. An alternative to eradicate most annual weeds is to graze
with sheep early after sowing. In addition, management techniques which include
crop rotations and stale seedbeds to 'flush' expected weeds would help to
lessen the problem.
In Conclusion
There is little new about the clover based farming
system. It was used for a great many years before the introduction of artificial
fertilizer.
The difference now is that we have reached a plateau in our intensification
of livestock farming and put simply, the figures do not add up any more. The
time has come to take a step back and ask what do our customers want and how
can we produce what they want at a cost that enables livestock farming to
prosper again. If farming does become more extensive we need to take a fresh
look at legumes.
Wrapped Bale Silage For High Silage Quality
Silage is made on most farms but surprising less than half conserve it in the form of wrapped bales. With this in mind we asked Nigel Ford to set out the basic ground rules for anybody considering introducing bale wrapping technology to their farming system.
Producing silage is no longer considered just another seasonal job but is now regarded as a highly developed science that requires care and attention.
During the 1970's the first polyethylene silage bags were used in the UK. Results were variable, due to excess air left inside and difficulty sealing the neck of the bag. Around 1985 the benefits of wrapping silage bales in balewrap stretchfilm were recognized and launched in the UK on a large scale. They quickly replaced the laborious system of bagging. The machinery steadily improved and led to the latest generation of fully automated wrappers. The system has proved popular and now accounts for an increasing share of the total silage market.
Why preserve by wrapping?
Each wrapped silage bale is in effect an
individual silo. This means that each crop can be arrested and preserved
individually according to its maturity as opposed to bulk silage, where crops
of different nutritional values are likely to be together. This enables material
of high nutritional value to be fed to high yielding autumn callers whereas
lower value crops would be better suited to dry cows.
The wrapped silage system is very flexible. Bales are easy to store and can be left in several locations around the farm. The likelihood of effluent is extremely small because each bale is sealed and usually has a higher dry matter content than clamped silage. Of course, compared with haymaking the results are less dependent on fine weather. Additional investment in wrapping machinery may be required but these initial costs can be avoided by using contractors.
Wrapped silage is transportable and therefore can provide a cash sale in times of surplus. Where summer grass is scarce it can prove invaluable. Bale wrapping is an ideal way to preserve surplus silage on farms where bulk storage is in use and the clamps are full. In these situations it can a so be useful when only a few animals are being fed, when it wouldn't be ideal to open the clamp.
Crops for Preservation by Wrapping
When ensiling forage it is important to preserve
as much of the nutritional value as possible. The nutritional value of a crop
can be defined as the energy and protein content per kg of DM. Feed intake
and live weight gain of livestock will be affected by it. And so the nutritional
value is affected by the crop, the time of harvesting, choice of fertilisers
and also the degree of accuracy of harvesting and preservation processes.
When crops are cut early and there is a balance between
energy and protein they will have a high nutritional value. Timing of harvest
is critical.
Normal sugar-rich grass crops, intended for silage will give good results.
On the other hand, the practise of wrapping late cut hay to save it from rain
can result in extensive mould spoilage.
Clean crops are of vital importance to producing hygienic
forage.
Contamination can have a disastrous effect, even in a completely oxygen free
bale. Losses can be extensive if fungi are exposed to air inside the bale
allowing moulds and spoilage to occur.
One of the ways to prevent the growth of undesirable bacteria is with the correct degree of wilting and the careful use of suitable additives. By ensuring the bales are as dense and as well shaped as possible, so that the air spaces within are small, fungal growth can be minimised. Whole crop and maize has been successfully wrapped but it is generally more difficult to compress these 'coarse' crops sufficiently with existing balers.
Mowing and Wilting
The timing of cutting is important to retain nutritional
value and also to enable the baler to adequately com- press the crop and produce
a dense, well-shaped bale Although the weather will determine the time of
cutting, mowing should take place just as the seed heads start to appear on
the grass or legume crop.
Once the crop has been cut, moisture will be lost through
evaporation.
Moisture loss is greatest during the first hour or two immediately after cutting
and it may be desirable to cut and spread grass before rowing up.
However, it is important not to contaminate the forage with soil and other
debris as this will lead to poor quality silage.
In favourable conditions the aim should be for a wilting period of no more than 24-36 hours. Do not leave the swath for more than 2-3 days but if this is unavoidable a suitable additive should be used. In damp, warm conditions moulds grow rapidly in the swath.
Wilting is one of the most important phases of successful baled silage making. It is important both for good fermentation and sufficient bale density. A DM content of between 35-45 per cent should be obtained to get good results. For wrapped silage, there should be no need for additives beyond 40 per cent DM. If moulds do occur under these conditions, they are likely to be because of poor wrapping or damage to the film after wrapping.
Wilting also affects bale density, which is directly related to the degree of compression. During the short period of time involved in compression of the crop no baler can dehydrate the plant cells entirely. However, if the cells have already been dehydrated, the baler then has a good chance, of producing dense well-shaped bales.
It is important to bear in mind that though some bales of low dry matter may be heavy; they are not necessarily dense. Correct DM con- tent is essential to minimise labour, machinery and film costs. Well-wilted bales keep their shape after good compression and can be stacked without problems.
Inoculate?
Where weather conditions are not good and the crop
is deteriorating rapidly, an attempt to salvage as much as possible must be
made. Wet crops are at a high risk from bacterial growth. This is where inoculants
come into their own.
The use of inoculates, which are freeze-dried lactic acid producing bacteria, has become common in recent years. The idea is to add a high concentration of the bacteria in a water solution when baling. These are essential for ensiling high protein material such as Lucerne or Sainfoin.
The Stretchfilm
The stretchfilm for bale wrapping must be of high
quality in order to meet a number of requirements. It should include UV stabilisers
to avoid film degradation in strong sunlight and have a high level of tack
to help ensure the cut end sticks to the bale and the seal remains intact
during storage.
Trials have shown that lighter coloured film such as pale green or white reflects more sunlight than black film, which absorbs it. This can cause great variations of temperature within the bale and nutrients can be damaged as a result. Also lighter coloured film has fewer tendencies to overstretch in hot weather ensuring better overlap in film layers.
By tightly applying 6 layers of good quality stretchable the circulation of oxygen is considerably reduced. The resulting lower nutritional losses are reflected in savings, which can be considerable when compared with the cost of the film.
Handling and storage
Careful handling and storage of bales is important
to ensure that the film remains undamaged and tight. It is useful to remember
that the overall thickness of 6 layers of film will only be about 0.1mm. To
protect the film, a purpose built handler is therefore necessary.
Round bales are best stored upright, as there is much more film on the flat ends for protection. Bales of high low dry matter should be stored in single layers to avoid pressure on the seals of lower bales if they are stacked.
Wrapped square bales should be stacked immediately after wrapping, and any bales which are 'banana shaped' should be stacked with the concave side facing downwards.
If the film is to remain tight and undamaged bales
must be protected from birds and other animals. A storage site away from trees
should be selected and a bed of fine material such a sand should be used as
a base. lf the site is in a field with farm animals a fence should be erected
around the bales.
PRINTABLE
VERSION
_________________________________________________________________________________________________________________________
Where have all the Bumble-bees gone?
Bumble-bees used to be a regular feature of the British
countryside. They were often considered so common as to be unworthy of special
mention by entomologists before the second world war and most collections
have representatives of over half the six- teen species of social bumble-bees
on the British list (a further two species were already extinct, or nearly
so).
Nowadays only six species are widespread, and even these can be quite scarce
in some parts of the country. Five species have been listed under the UK Biodiversity
Action Plan: Bombus distinguendus, Bombus humilis, Bombus ruderatus, Bombus
subterraneus and Bombus sylvarum.
Nesting sites are often at a premium. Many nests are made in old mouse and vole nests as this provides insulation material. The nest may be made on the surface in tall, but open, grassland or underground according to species. Nest searching queens are easily recognised as they fly along slowly with a typical zig-zag motion, dropping to the ground to explore a suitable hole or pile of old vegetation. If a queen finds an area which she likes, she makes an orientation flight of ever-increasing circles, which may finally be hundreds of metres in diameter. During this flight she is learning the landmarks necessary to re-find the area. New workers, leaving the nest for the first time, perform the same type of flight.
Bumble-bees need quite a complex habitat, with different areas being used for different parts of their life-cycle. They require:
- Nesting areas
- Foraging areas where they may find nectar and pollen, both to feed themselves
and to provide food for the brood mating areas
- Hibernation areas where fertilised queens spend the winter
Many nests which are founded during the spring do not survive to produce new queens at the end of the summer. In one study, which looked at one of the communist species, only 20% were successful. Bumble-bees nests occur at relatively low densities. Typically each species will only have one or two successful (those which produce new males and females) nests per square km of good quality habitat. This means that areas containing suitable habitat need to be large in order to support viable populations.
Bumble-bees gather both pollen and nectar from the flowers they visit. The nectar is mainly used to fuel the adult bees’ flight and a little is fed to the developing larvae. The most important food for the larvae is pollen, which is collected on the back legs of the foraging workers.
Although they will not visit many different plants for
nectar and pollen, some plants are particularly well utilised, particularly
for pollen.
These are mainly from the plant families which include the dead-nettles and
pea-flowers. Legume pollen may account for as much as three- quarters of the
pollen collected during the summer and clovers are especially important. Red
clover has a particularly long flower-tube and is specialised for pollination
by those bumble-bee species which have longer tongues. It can provide, if
areas are grazed or cut in rotation, a very long-seasoned foraging resource.
White clover is also heavily used by foraging bumble-bees, particularly those
with shorter tongues. During the spring sallow blossom, white dead-nettle
and birdsfoot trefoil (or 'eggs and bacon') are important food sources, whilst
hemp-nettles, field scabious and black knapweed are important towards the
end of the summer.
Forage for Bumble-bees
Bumblebees are active for a large part of the spring and summer, consequently
continuity of forage resources is very important. As they can fly they can
exploit resources in different localities around the nest but sufficient forage
must always be present throughout the season.
Grazing or cutting management which removes all the available for- age throughout
a large area all at once is very damaging to bumble-bee populations.
Pre-intensification, British farm land, dominated by a large number of small, usually mixed farms provided plenty of habitat which was suitable for bumble-bees. Relatively small, unfertilised fields supported good stands of 'common' plants such as red clover, birdsfoot trefoil and black knapweed. They were grazed by a few cattle in rotation, or cut for hay; conditions which resulted in there always being forage available within easy flight distance of a nest. The headlands of arable fields would be unglazed whilst they were in that phase of the farm rotation and would provide suitable nesting areas.
Creating Habitats
Between July and September new male and female sexual bees are produced. According
to species, males wait for females around solitary bushes, or patrol a number
of scent- marked plants or enter a nest where new females are preparing to
fly. Newly mated queens quickly find a suitable place to hibernate. Hibernation
sites are unknown for most of our bumble-bee species, but it is likely that
many of them hibernate in litter or underground in taller grassland, possibly
using old small mammal nests. Some species hibernate in light woodland or
under hedge banks North facing locations are preferred as these take time
to warm up during the spring and the bees will not emerge from hibernation
during a short warm spell in the middle of winter.
Unfortunately, most of the modern countryside provides little opportunity for bumble-bees to complete their life-cycle. Under modern, intensive, farming methods there has been an enormous loss of hedgerows and field margins, with cultivation being practiced right up to the margins of fields and a consequent loss of both foraging and nesting areas. Rotations are short and reliant upon large inputs of fertiliser, with hay-making being replaced with silage making. The red clover ley, once a central part of rotation, is not part of these rotations. Farms and fields are much larger and tend to concentrate upon a much smaller set of crops, or have much larger herds of animals, reducing the foraging opportunities still further. Bumble-bees which are hibernating in fields may be destroyed during autumn ploughing.
Modern agri-environment schemes are attempting to redress the balance, with farmers being encouraged to provide areas within their farms where farmland wildlife can survive. This process is not only for landscape and conservation value, there are good ecological reasons why a more diverse farmland makes long-term farming more sense. For instance, flowers require pollination before they set seed. Bumble-bees are very efficient, even essential, pollinators for some crops.
Experimental schemes are being developed with farmers and conservation land-owners to develop management prescriptions which will maintain and restore bumble-bee friendly habitat throughout Britain. These schemes are concentrating on the potential of buffer-strips, restored hedgerows and headlands to provide suitable habitat, within a modern farmed countryside. Within cropped fields small sections of clover leys which are not cut can also provide useful food resources for bumble-bees.
Management to support bumble-bees in the countryside requires the provision of three main things
- Suitable nesting sites,
- A succession of areas with suitable foraging opportunities.
- Suitable hibernation sites.
Areas chosen to provide bumble- bee habitat should not be alongside roads, as road-kill is a major source of loss of both bumble-bees and the birds which will be attracted to such areas. Neither should such areas be created by additional sowing into remnants of unimproved vegetation, which are best managed by light, rotational grazing or cutting and will provide foraging areas naturally.
The creation of nesting and hibernation sites requires
little management input. A rough, tussocky grass- land, such as develops naturally
on unglazed or unmown headlands, is suitable. Such areas should be cut, with
cuttings removed, or grazed every three to five years to stop the accumulation
of excessive plant litter and the development of stands of false oat-grass.
Management should be carried out on a rotation, with only parts of the habitat
managed each year. Occasional rough ploughing of parts, sufficient to turn
over the grass, but not bury it fully, can provide further opportunities for
voles and mice to nest, which then provide future bumble-bee nest sites.
This type of habitat will also be good for barn owls and provide winter cover
for partridges. The modern decline of previously common farm- land birds is
of great concern.
Changing times
The provision of foraging areas requires a little more effort as the regular
grazing or cutting of such areas helps maintain the flowers. If cutting is
used then it is important that the mowings are removed. If they cannot be
picked up and baled then a silage cutter, or even a flail used on a windy
day, can be used to blow them away. It is also important that cutting or grazing
is carried out on a rotational basis throughout the farm. This ensures that
the bees always have places to forage. These areas will also provide habitat
for partridge and skylark.
A suitable grassland, with clovers, birdsfoot trefoil and black knapweed, may well develop on its own if the area is managed as above, especially
if there is not a high level of fertilisers present. However, on very intensively farmed areas, sowing a suit- able seed mixture will hasten the process considerably. Seed may be obtained by scattering cuttings from a meadow which already contain these plants; black knapweed seed may be hand collected and scattered during the autumn. Alternatively, suitable seed mixtures are increasingly available through commercial seed merchants. In this case it is preferable to use the native varieties, rather than the often cheaper continental ones.
For those considering organic farming or possibly in nitrate restricted areas, the restoration of a clover based ley may return as an essential part of farming practice. The successful production of clover seed, and that of many other legume crops, depends upon the presence of suitable bumble-bees or honey bees are not suited. Hence the provision of bumble-bee habitat becomes part of the essential management of the farm.
Habitat restoration as outlined above may qualify for one of the existing agri-environment payments. It requires the removal from cash- cropping of a relatively small percentage of the intensively farmed area and will benefit other formerly common farmland wildlife as well as bumble-bees.
Pests and Diseases - How to recognise and control problems in newly sown leys
Newly sown grass seldom fails totally as a result of attack by pests and dis- eases. However, pests or diseases often and needlessly impair establishment to a worrying extent. Failure to establish a vigorous, even cover soon leads to patchiness, the subsequent invasion of weeds and the rapid decline of the sward. Consequently it is essential to ensure that as many of the seeds as possible germinate, establish quickly and grow rapidly. To get the seedlings off to a good start, attention must be paid to correcting any deficiencies and this includes liming where necessary and providing adequate levels of N, P and K.
The time of sowing is also important. In central Southern
England spring sowings should be made in March-April and autumn sowings
in mid August - mid September. It is far too late to sow white clover after
early September for it to be reliable. Also, producing a fine firm seedbed
encourages the young seedlings to establish, grow quickly and be better able
to withstand attack by pests and diseases. Heavy rolling closes the nooks
and crannies in which slugs lurk and crushes leatherjacket burrows, making
life more difficult for them.
During the establishment phase, little green material is present and pest and disease attack is concentrated on it. Several pest species including slugs and leatherjackets attack grass seedlings. More important than these though are the larvae of frit fly. The only disease of significance to grass seedlings is Fusarium culmorum. Red and White clover seedlings are attacked by sitona weevils and slugs, but diseases seem unimportant.
Frit fly
By far the most important pest of newly sown perennial and Italian ryegrass
is frit fly. Damage usually appears as patches of seedlings within the sward
emerging poorly and growing only slowly. Affected seedlings often appear weak
or stunted. The larvae which cause the damage can be seen by the naked eye,
but only after careful laboratory dissection of a sample of tillers. It is
not practicable to search for and count larvae in the field.
Grass seedlings are at their most attractive to egg-laying females, when they have 2-3 leaves. Unhappily for farmers, in autumn, seedlings often reach this stage at about the time the frit adult population reaches its peak. Eggs are laid on and around the seedlings and the minute larvae burrow-in and mine within the base of the developing plants. Larvae can also burrow-up from the ploughed-in turf of a previous sward and infest the re-seed (or a following cereal crop). In direct- drilled grass, frit larvae migrate easily from the desiccated remains of the old sward to the emerging seedlings of the re-seed and cause great dam- age.
There are three generations of frit fly each year. Adults
of the third generation are on the wing in August/September and it is larvae
arising from eggs laid by them that cause the damage. Dow Agro Sciences in
collaboration with IGER have produced a risk assessment chart that gives clear
guidelines on when to use chlorpyrifos (eg.Dursban 4) at full or half dose
rate to control frit fly. Clover, timothy and coltsfoot are not affected by
frit fly. The major risks are to perennial and more especially Italian ryegrass.
spring sowings are seldom if ever affected, but sowings made in autumn are
usually damaged to some extent. There is a major risk to swards sown in mid-late
August. Direct drilling almost always leads to significant damage by frit
larvae (even in spring sowings) which migrate easily from the old desiccated
sward to a reseed.
Leatherjackets
The risk of dam- age to newly-sown grass and clover by leatherjackets stems
from these large insects surviving seed-bed preparation and being carried
for- ward from the previous crop. Clearly previous cropping history will have
an important bearing on this carry- over. There are likely to be few or no
leatherjackets in a previous arable crop and the risk to a sward following
them will therefore be very low. However, established grassland is often heavily
infested and there is a far greater risk. Symptoms of dam- age are bare patches
appearing in the new sward often associated with large numbers of birds (especially
crows, rooks and starlings) probing for the larvae. The larvae are a dull
olive green, with no distinct head and no legs. They may be up to 35 mm long
and have a rubbery feel they are difficult to squash between thumb and forefinger.
Again Dow Agro sciences have produced a risk assessment chart and this gives
clear advice on when the application of chlorpyrifos may be necessary.
Leatherjackets may also feed on and damage clover seedlings. The risk of damage by leatherjackets is greatest when grass follows grass especially if the interval between crops is less than two reeks. Problems are also more likely in predominantly grassland areas and where damage has been noted on previous occasions.
Slugs
Slugs are voracious feeders and may destroy grass or clover seedlings. Damage
caused by them is patchy. A tell-tale sign of attack is the slime trails that
they leave behind. Since they are nocturnal, a visit to the field after dusk
with a torch will reveal their presence. Prevention is better than cure and
is best achieved by producing a fine, firm seedbed with no cracks, crevices
or clods where they can lurk. Exposed on the soil surface with nowhere to
hide slugs soon fall prey to birds and various mammals or they simply desiccate.
Should chemical control be needed there are several proprietary products available
based on methiocarb or metalde-hyde.
Weevils
Sitona weevil larvae attack the root systems of mature red and white clover
plants, but the adults attack seedlings as well as leaves of older plants.
The adults which are the size of a match head can graze seedlings down to
stump. There are no chemical control methods approved specifically for the
control of sitona on clover seedlings, but chlorpyrifos (e.g.
Dursban 4) applied to control frit fly or leather- jackets in accompanying
grass seedlings will also control the weevils.
Fusarlum eulmorum
Spores and other propagules of this disease are present in virtually every
crumb of soil in the UK. A1l that is needed for this pathogen to become a
problem is a susceptible host, e.g. ryegrass and appropriate environmental
conditions (dry and warm). The disease attacks seedlings after germinating,
but before emergence. The only symptom of attack seen in the field is the
failure to emerge of many seedlings. Extensive work by IGER has shown that
on average across a wide range of soils, sowing dates and sites on average
some 20% of ryegrass seedlings are killed by Fusarium. Sowing deeply and in
dry conditions exacerbates problems and a good method of avoiding problems
is to sow shallowly (1 cm) and when the soil is not dry.
Investigation into Nitrogen recovery using Green Manures.
Project Brief:
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Currently Joanna Doel from The Royal Agricultural College is using a number of our test plots to research the use of short and long term green manures as a source of nitrogen for the following test crop. She hopes to establish the influence of different species, sowing legumes and cultivation techniques on nitrogen recovery. |
The Data will then be fed into a model for predicting Nitrogen yields and the pattern of release from the green manure into the subsequent crop.
Crops being tested:
Ryegrass/Red Clover
Cocksfoot/Red Clover
Phacelia fallow after Sweet Clover
Field trials being explored:
Cultivation treatments: glyphosate v rotavating
Early/late cultivations followed by ploughing
Test crops will be winter and spring wheat
Data being recorded:
Species yield
C:N ratios
Nodulation
..with the aim to gather information regarding the quantity of nitrogen generated.
Methods:
Indications of Nitrogen availability and recovery are obtained from regular
mineral N sampling as well as vegetation yield sampling at the test crop.
Information regarding nitrogen processes within key plots is obtained from the use of mineralization cones and leaching probes.
The following images were taken at our trials ground at Moreton-in-Marsh 20th September 2007, and show Joanna in the process of setting up the experiments using specialized machinery to take core-samples from the soil and plant the measurement apparatus. Please click the thumbnails to view the larger images.
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• Nitrogen Fertilizer – Dramatic rise in price – now approaching £300.00 per tonne.
• Cost of bought in protein zoom
• Wheat price trebled in last two years
What should farmers do to mitigate these DRAMATIC extra costs?
ANSWER – Produce home grown protein feeds
Legumous plants are the best source owing to their ability to utilise the plentiful supply of free nitrogen available (80% of AIR IS NITROGEN). We are referring to :
Firstly the larger legumes of which the most popular is RED CLOVER . This is now estimated to occupy 60,000 hectares in the UK and is the main stay for those farmers currently utilising forage legumes. Besides providing large yields of high quality silage, red clover is a wonderful preparation for growing a cereal crop.
Other more specialised large legumes are LUCERNE, primarily a cutting crop with very high yields of high protein material and SAINFOIN which is suitable for both cutting and grazing.
SAINFOIN is a particularly good feed for young growing stock owing to its very high palatability.
WHITE CLOVER for grazing is still the most important source of home grown protein. Owing to its palatability there is an increased intake by animals compared to grass.
Of course the symbiosis of white clover and grass means a high yield WITHOUT ANY NITROGEN applied. In research by SAC it was shown that grazing a mixed sward of clover and grass cost two thirds of grazing a pure sward of grasses. This was before the present DRAMATIC increase in cost of Nitrogen fertilisers.
Again a further benefit is using the ploughed up sward to grow cash crops at reduced cost.
IntroductionClover plants are able to extract nitrogen from the air,
which itself is three quarters nitrogen, indirectly into the soil via bacteria
in nodules on plant roots. Red and white clovers are the two key forage legumes
and these at high proportions in grass leys can fix 150-250kg of useable nitrogen
per hectare/year. Scientific trials at research institutes such as IGER and
SAC have shown that high clover leys are capable of producing reasonable yields
at very low cost and therefore offer a real alternative to the more expensive
fertilised grass only leys. Clover plants are also high in protein and therefore
can reduce the need for bought in feed. When sown with grass, clover increases
the protein content of forage by about 20%.
There are also concerns about the effects of increasing diesel costs which
affect the very application of fertiliser itself. Coupled with this is the
burden of record keeping and even the disposal of polypropylene and plastic
bags. Finally, imminent changes to NVZ’s mean that grass farmers will
be restricted by a further reduction of 30kgN per hectare.
For all of these reasons and the likelihood of higher oil and agricultural
commodity prices the move to clover is likely to accelerate.
How much nitrogen can
clover fix?
Pure clover crops can fix as much as 250-400 kg N/ha. But as red and white
clovers, the two most important forage legumes in the UK are planted with
grass the amount of nitrogen fixed reduces to between 150-250 kg N per hectare.
Red clover usually fixes more nitrogen than white clover during the first
two years but beyond this both types are similar. There is much scientific
evidence to support the case for clover as a nitrogen fertiliser replacement.
The LEGSIL Project, for example, which was carried out between 1997 and 2001
concluded that red clover yields were comparable to grass receiving 200 kg
N/ha.
To fix enough nitrogen it is necessary to have sufficient clover in the sward.
IGER have consistently maintained that leys need to contain between 30-50%
clover to effectively produce high levels of nitrogen. Breton dairy farmer
André Pochon, who modeled the French high clover system for beef production,
also held the same opinion. Leys with low clover contents will not provide
an alternative and will only offer high yields to achieve reasonable stocking
rates if they receive artificial nitrogen fertiliser.
The cost of nitrogen fertiliser
In order to compare conventionally fertilised grass against a high clover
ley it is necessary to calculate the cost of nitrogen fertiliser. (High clover
ley seed mixtures cost between £10-25 per hectare more than grass only
leys.)
The amount of nitrogen fertiliser required for grass only leys depends largely
on stocking rates. Other factors such as soil type, previous cropping and
availability of other sources of nitrogen such as slurry, FYM and waste products
will affect application rates. For the purposes of comparison stocking rate
figures and N application rates have been drawn from John Nix (Farm Management
Pocketbook).
Dairy - Nitrogen fertiliser requirement.
Those with 2 cows per hectare will need around 220 kg N to provide sufficient
grass from a ryegrass only sward for grazing and silage. At a higher intensive
stocking rate of 2.5 cows per hectare 350 kg N would be necessary to provide
enough grass.
Sheep and beef - Nitrogen fertiliser requirement.
For lowland sheep and beef production 14 ewes or 1.8 cattle per hectare have
been used as average stocking rates for these calculations. To provide sufficient
forage from grass 200 kg N will be required.
Cost of nitrogen fertiliser per hectare at varying stocking rates
|
Fertiliser price |
Dairy |
Dairy 2.5 cows/ha 350 kgN |
Sheep/Beef 14 ewes/1.8 beef/ha 200 kgN |
|
£150/tonne |
£96 |
£152 |
£87 |
|
£300/tonne |
£191 |
£304 |
£174 |
|
£500/tonne |
£319 |
£507 |
£290 |
At Application costs are not included. Cost of N fertiliser at 22nd July 2008 £340 per tonne.
Protein
Protein sources After the 1996 BSE crisis when mammalian animal products were
withdrawn from the market, farmers had to find alternative sources of protein.
In those difficult years there existed relatively cheap and good supplies
of soya, fishmeal and other specialised grains which were readily bought by
farmers. Today, again we see protein as a restricting factor with gross margins
under pressure. One solution put forward by many farmers is to grow high protein
crops and therefore become more self sufficient with less need for bought
in feed. Almost 90% of home grown protein comes from grass silage (ref R Jones,
IGER). The remainder is mainly from maize, whole crop silage and lucerne and
it is unlikely that there will be any more new protein crops becoming available.
So, improving the protein content of grazed grass and silage is likely to
be the best way of increasing profitability in the immediate future. This
can be done by growing mixtures of grass with clover instead of pure stands
of grass. Clovers are rich in protein and when included in a ley at high levels
the forage will typically contain 20% more protein than a grass only crop.
Additionally, according to Jones, the available protein in legume silage is
much greater. His work showed losses in ensiled grass leave only 40% available
protein, the rest being degraded, but with a well fermented clover rich silage
the amount left in an available form is 60%.
Digestibility and palatability
Clovers are more digestible than grass and this is one reason why livestock
perform well when fed clover. Clovers are generally found to be palatable
to sheep and cattle. This is important as it enables productive animals to
consume more forage. More forage intake with a high protein content leads
to greater live weight gain and milk yields.
| Characteristics of white clover and perennial ryegrass |
||
|
White Clover |
Perennial Ryegrass |
|
| Crude Protein % |
27 |
17 |
| Digestibility - % D-Value |
75-82 |
66-75 |
| Amount eaten by sheep (DM intake kg/day) |
1.9 |
1.4 |
Choosing between red
and white clover
Clovers come in different forms and the first decision to make when deciding
to grow clover is which one to grow. From an agricultural perspective there
are two main forms; Red and white clover. These account for more than 90%
of the current clover seed sold. They grow successfully on most soils throughout
the UK, are drought resistant, high in protein and fix nitrogen. (Other forage
legumes such as lucerne, sainfoin, birdsfoot trefoil, crimson and alsike clovers
are available for specialist use but for the purposes of clarity will not
be discussed further here.)
Red clover is for silage
This has a high yield of around 15t DM/ha and is most commonly used for silage
production. It is an upright plant which can yield up to 30% more than white
clover. Red clover leys are cut for silage at the end of May. Two or three
more cuts follow throughout the summer and autumn. It is sown in leys to last
between 1 and 4 years. Red clover grows well on most soils and is drought
resistant.
There is a wealth of published scientific research on the subject. John Frame, a past President of the British Grassland Society was an authority on red clover having done some classic research work on it while working for SAC. This work was carried out during decades of agricultural intensification and has now become an extremely valuable reference to those now looking to exploit legumes. Additionally, the LEGSIL trials, which ran for four years at many European institutes including IGER, showed red clover to have the lowest cost of production making it a very economical crop to grow.
Types of red clover
Red clovers can be broken down into two distinct types; Early and late flowering.
There is a difference of around 10-14 days between the two with the earlier
types flowering (67D) in England at the end of May. Generally the early varieties
e.g. Milvus, Merviot and Global are the most commonly used for silage as they
re-grow well to provide a second cut. The late varieties e.g. Altaswede can
be used on late or wet ground or where just a single cut is required. Late
red clovers are more suited to grazing.
Typical red clover seed
mixtures
It is important to obtain the correct balance between the grass and clover.
One quarter of the seed mixture should be red clover with the remainder grass.
The overall sowing rate should be 12-14 kg per acre (30-35 kg per hectare).
Red clover is very competitive and is best grown with aggressive, high yielding
short term grasses such as the Italian or hybrid forms of ryegrass. When grown
with clover these high yielding grasses significantly increase yield and this
is the reason why red clover is not sown alone. When red clover is sown at
high proportions in a ley and with less productive grasses such as late heading
ryegrasses, meadow fescue or timothy, red clover can create a canopy and dominate
the sward.
One-Two Year Red Clover
Mixture
3.00 kg MILVUS red clover
3.00 kg GEMINI tetraploid Italian ryegrass
3.00 kg FOX Italian ryegrass
3.00
kg FABIO tetraploid Italian ryegrass
12.00 kg per acre £35.60 (30 kg/ha
£89.00)
Three-Four Year Red Clover Mixture
3.00 kg MILVUS red clover
3.00 kg ABERECHO
tetraploid hybrid ryegrass
3.00 kg ABEREXCEL tetraploid hybrid ryegrass
3.00
kg CALIBRA tetraploid perennial ryegrass
12.00 kg per acre £40.57 (30
kg/ha £101.43)
(Price and mixture ref. Cotswold Seeds. Autumn Catalogue 2008)
Making red clover into
silage
Red clover is low in dry matter and contains a low amount of water soluble
carbohydrates. This means that for satisfactory fermentation to take place
it will need to be properly wilted. It is usually worthwhile fine chopping
the wilted material and applying an effective additive. Red clover can also
be made into hay. Leaf loss can be a problem if hay is on the ground for too
long.
Place in rotation
When red clover was at the height of popularity thirty years ago some farms
had a problem with ‘clover sickness’. This was a combination of
the soil borne disease sclerotinia and the pest stem eelworm. To avoid these
problems red clover leys should have a gap of five years. As with many crops,
problems can build up if the same species follow too closely in a rotation.
White Clover is for Grazing
White clover is a low growing, persistent plant that is lower yielding than
red clover. It is therefore principally used for grazing leys which are expected
to last for two years or more. When grown with perennial ryegrass, yields
can be expected to be in the region of 10-13t DM/ha. It was thought that white
clover grows later in the spring than grass receiving N fertiliser. This situation
changed during the 1990’s with the successful introduction of earlier
growing varieties of clover such as Aberherald. Trials over eight years by
J Bax on SAC’s Acrehead System Study at Crichton Royal Farm showed that
there was only a 2.4 day difference in the date of turnout between clover/grass
and grass only swards. Also, where necessary for very early spring growth,
30kg N (artificial) can be ‘tactically’ applied without significantly
damaging or reducing clover content. Alternatively, an area of grass plus
N could be maintained specifically to provide very early grass.
Types of white clover
White clover is classified by leaf size. Broadly speaking there are three
categories; very small, medium and large leaved clovers. The very small, low
yielding but extremely persistent type is known as ‘wild white’.
These little clovers fill the base of the sward and can be grazed hard especially
with sheep. Original varieties such as S184 and Kent which have been used
for over fifty years are still very popular today. Medium leaved varieties
such as Aberherald and Crusader are more modern introductions and offer yields
well in excess of the wild whites. They are also more competitive, persistent
and offer good early spring growth than older varieties such as NZ Huia. The
large leaf types such as Barblanca and Alice are the highest yielding. However,
these large leaved varieties do not survive well when grazed hard with sheep.
Therefore these are best sown in silage or cow grazing leys only. For most
situations it is best to sow a mixture of types to allow for grazing and/or
silage.
Typical white clover
seed mixture
White clover seed is about half the size of red clover and is included at
a lower weight for this reason. At an inclusion rate of 1.5kg per acre (3.75kg
per hectare) the white clover content of the sward should be between 30-50%.
‘POCHON’
Type Two-Four Year White Clover Silage/Grazing Ley
2.00 kg ABEREXCEL tetraploid hybrid ryegrass
3.00 kg CALIBRA
tetraploid perennial ryegrass
2.50 kg ABERSTAR perennial ryegrass
3.00 kg
DUNLUCE tetraploid perennial ryegrass
0.60 kg ABERHERALD white clover
0.60
kg CRUSADER white clover
0.30 kg BARBLANCA white clover
12.00 kg per acre
£38.25 (30 kg/ha £95.63)
‘POCHON’
Type Long Term White Clover Grazing Ley
2.50 kg TWYSTAR perennial ryegrass
2.50 kg PORTRUSH perennial ryegrass
3.00 kg MAGICIAN tetraploid perennial ryegrass
2.50 kg DUNLUCE tetraploid
perennial ryegrass
0.60 kg ABERPEARL white clover
0.60 kg ABERHERALD white
clover
0.30 kg S184 wild white clover
12.00 kg per acre £39.51 (30 kg/ha
£98.78)
(Seed mixture formulations based on M. Pochon. Price and mixture ref. Cotswold Seeds. Autumn Catalogue 2008)
Sometimes red clover is sown with white clover leys. Red clover is quicker to get established and is more productive during the first two seasons. It must not be included at more than 1kg per acre (2.5kg per ha) or it may become dominant.
Sowing clover seed mixtures
Clover seed can be sown much in the same way as grass only seed mixtures except
more attention must be paid to timing and depth of sowing. Clover requires
at least 7°C before satisfactory germination and therefore sowing should
take place from mid March in most districts. Clover can be sown at any point
through the summer provided that sufficient soil moisture is available but
it must not be sown too late in the autumn. Mid September is considered by
most to be the latest safe time but not clovers can grow later if warm conditions
allow. Ryegrass only leys can often be sown later than this with satisfactory
results. Clover will not germinate satisfactorily if it is sown too deep.
The chart below illustrates the need for shallow sowing.
Clover leys can be sown directly or undersown to spring cereals. (If undersown it is important to reduce the cereal rate to two thirds so that the cereal is not too competitive.) The seed can be broadcasting or drilled. Although very accurate, cereal drills should be used with care as they can bury the seed too deeply.
Lack of consolidation at sowing time can result in poor establishment. Too frequently, it can be observed that headlands and wheeling’s have establishing clovers, but elsewhere there may be none. This is often attributed to a lack of consolidation. Clover seeds are smaller than most grasses and need to be sown into a well prepared and consolidated seedbed so that moisture can travel from soil particles to the seed. Clovers are more vulnerable to drought after sowing than grasses. This is because grasses have several root tips which emerge at different times whereas clovers have just one. It is therefore essential to roll before and after sowing for a successful take. Robert Handy of Andoversford, Cheltenham had three golden rules when it came to sowing clover leys. 1. Roll. 2. Roll and 3. Roll again. Robin Hill of Cotswold Seeds claims that you should be able to ride a bicycle across the seedbed prior to sowing. These illustrate the requirement to roll.
Over-Seeding
A further method of utilising clover is to introduce it into existing grass
without re-seeding. The main advantages are that there is not much interruption
to the use of the field and with seed costing in the region of £15 per
acre (£37.50 per hectare) clover content can be increased at minimal
expense. Timing is important. It is best to avoid sowing when the existing
grass is growing vigorously during May and June, so either sow March-April
or July-September. If there is excess growth on the existing grass this should
be removed by grazing or cutting before sowing.
The seed can be drilled or broadcast. Comb harrows with
seeders such as the ‘Opico’ or Einbock’ give good results
and are widely available. Alternatively, a grass drill such as the ‘Moores’
or ‘Aitchison’ may be used. Heavy direct drills with discs designed
for cereals do not produce such good results. If the seed is to be broadcast
a little tilth should be obtained by harrowing first. For low sowing rates,
a suitable applicator will be needed. The electronically driven spinners e.g.
‘Stocks’ are good for applying these low rates and will distribute
clover seed 10-12 metres.
Once the seed is sown it should be rolled in with a heavy roll or stocked
heavily but for a short time with sheep. (If left on too long, sheep can overgraze
clover seedlings.) Good results have also been obtained from set stocking
with low numbers of cattle until the clover has established. Nitrogen applications
should be ceased.
Fertiliser requirements
for new clover leys
Phosphate and potash levels need to be at an index of 2. Clover production
will be severely restricted if these elements are too low.
Newly sown clover leys can benefit a small amount of applied N (30kg per hectare) especially when following a cereal rotation. Although not essential, this promotes initial growth on both clover and grass until the clover plants become estab