Organic Farming

The central feature of all organic cropping systems is the rotation (it is possible to have an organic livestock system based on permanent grassland).

The design of the rotation is the major influence not just on nitrogen supply to the crops, but also on weed control and on soil-borne diseases and pests. The crop rotation must have a balance between fertility building crops (e.g. grass/clover ley) and exploitative crops (e.g. cereals, potatoes).

For example:

The foundation stone for most successful organic farms is the grass/clover ley. N fixation by clover provides an N fertiliser factory on the farm. Soil fertility is built up under the ley for subsequent exploitation by the following arable crops when the ley is ploughed, through the release of N from soil organic matter by the mineralisation process.

Leys require ruminant livestock for their utilisation and ruminants produce FYM, the currency by which nutrients are re-cycled around the farm to priority crops e.g. silage, roots and vegetables, 2nd and 3rd year cereals after ley.

Organic farming practices aim to minimise loss of nutrients from the system, and maximise the efficiency of nutrient recycling within the farm (e.g. avoidance of losses from manure heaps, optimising mineralisation of soil organic N).

Basic soil fertility inputs of natural materials (e.g. lime and rock phosphate) are permitted within the standards.

Weed control strategies in organic arable crops should be based firstly on a rotational design which restricts weed seed build-up in the soil and secondly on techniques which enhance the competitiveness of individual crops, such as choice of species and varieties which have rapid ground covering ability.

Disease and pest control strategies should also be based on prevention: correct choice of rotation and, at the level of the individual crop, crop varieties or mixtures of varieties which have good disease resistance, e.g. for foliar and tuber blight resistance in potatoes.

Insect pest populations should be minimised by encouraging natural pest predators, e.g. by the provision of appropriate vegetation in field margins and in-field strips to provide cover for ladybirds.