Long term fertility builders are the ultimate green manures providing significant and long lasting benefits. Grasses and deep rooting legumes grown over a one to three year period can add massive amounts of organic matter and leave the structure of the soil in excellent condition. They also build up very high levels of nitrogen which will be used by subsequent first wheat and root crops. Therefore, substantially reducing the need for artificial fertiliser.

The ultimate soil improving technique

Deep Roots - Top Soil
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 ranging from light and brashy land to the heaviest clay.

Plant roots and plant root aftermath that penetrates to a great depth vastly increases 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 crops is made possible. Creating a soil profile with an increased water holding capacity can not only help to reduce run off and lesson the effect of flooding but it can also provide a valuable reserve of moisture in drier times.

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 leguminous plants. 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.

Hardpan and compaction can be caused by machinery or it can form naturally at any depth. By far the easiest, cheapest and most natural way to break up and control the development of this troublesome condition is to include the strongest rooting species of plant in the rotation. Some herbs, legumes and grasses have root structure very capable of this task. For example chicory, the ability of its roots to penetrate even the thickest of hardpan is well documented.

There can be many minerals and nutrients locked in the subsoil that are beyond the reach of shallower rooting plants. It is possible to extract this valuable resource by exploiting deep rooting herbs in a ley. Many herbs absorb minerals and nutrients from a great depth. These are transferred to the surface and are made available once incorporated during a rotation. This action can be of benefit to both animal and soil health and should be more widely utilised.