Soil and manure management and crop nutrition

Correct soil management is crucial on an organic farm, as it must provide the bulk of the nutrients for crop and grass growth.

Sources of nutrients

Soil and the rock minerals and organic matter contained in soil provide many of the nutrients for plant growth on an organic farm.

Legumes, particularly clovers, are a key fertility building element in this as they work with rhizobial bacteria, which produce special nodules on their roots, to convert atmospheric nitrogen into soluble nitrate ‘fertiliser’.

This is utilised in two main ways:

Nitrogen ‘leaks’ out from the clover root nodules into the surrounding soil to feed other non-legume plants. This is evident where clover provides nitrogen for grass growth in a grass-clover sward.
When a legume crop or legume based sward is ploughed up, considerable quantities of nitrogen are released to the following crop along with organic matter containing a wider range of nutrients.

As a supplement to this, farmyard manures, composts and slurries are incorporated into the soil, and are an important source of phosphate, potash and other nutrients, particularly for crops demanding a high level of nutrients.

Soil management

Some key elements in soil management at Greenmount are:

Correct timing of ploughing and cultivation to minimise nutrient losses through leaching
Liming to provide the optimum pH for nutrient release
Avoiding bare ground over winter, thus reducing leaching
Use of a 'shakerator' to break up soil pans and improve drainage on a regular basis.

Manure and slurry management

It is very important that nutrients are retained in the system. Key to this are:

Provision of storage facilities which prevent nutrient losses
Composting manures to provide a more stable product