LEY farming is a system in which grasses and legumes are cultivated in proper rotation for hay, silage and pasture to meet maximum livestock needs and improve and conserve soil fertility.

Leys are temporary, short-term (two to five years) especially sown pastures comprising grasses and legumes. They are used for grazing in succession of ploughs and the land is ploughed again after a predetermined period. It is a dynamic and integral system of agriculture which encompasses soil, plants and livestock together. In this system emphasis is placed on the value of grass-legume mixture to get fodder for livestock and improve soil fertility for obtaining higher yields of arable crops.

For maximum crop yield, the best use of available land has to be made and the latest methods of crop husbandry are put into practice. But this depends on the availability of scientific information on different aspects of agriculture in an easy applicable form.

Farmers have recognised that yields of arable crops are the highest after ploughing up of old grasslands. They tend to decrease with successive crops. In primitive agriculture when the land was in abundance, the cultivated fields were abandoned when yields started to decline, and new fields were taken over for cultivation.

After this stage of ‘shifting cultivation’, the system of ‘following of land’ came in vogue. In this system when fertility declined, the land under cultivation was left as fallow for some time to recover and was prepared for farming again. The fallow was frequently ploughed to wipe out weeds, maintain proper tilth and conserve soil moisture and nutrients.

In the next stage of agrarian development, ‘legumes’ were introduced in place of fallow. The practice of ‘crop rotation’ was thus initiated to obtain better yield with maintenance of soil fertility. At present ‘leys’ are also recommended as a well-managed sequence of crop rotation.

In a subtropical country, residual and added organic manure get oxidised rapidly. Consequently, the soil is rendered poor in organic matter and nitrogen. Organic matter, therefore, must continuously be replenished while nitrogen can be added through fertilisers. Organic matter is one of the most important indices of soil productivity, as it provides energy for microbial activity, besides being the source of plant nutrient.

Moreover, the soil which is rich in organic matter has been found to respond better to the application of nitrogenous fertilisers. But only 40 per cent of the cattle dung is available for manuring, the rest being wasted or used as fuel. Green manuring for adding organic matter to soil has not been accepted by farmers on a large scale, since it involves sacrifice of one crop. As an alternative, inclusion of grass-legume ‘ley’ in crop rotation can be introduced without the loss of an economic crop. The advantages of such a cropping system are manifold.

The production of grass-legume mixtures for fodder to provide the required amount of proteins and carbohydrates in cattle feed would also be the basis of an improved livestock industry to provide more milk and better draught power for cultivation. A cut and carried ley crop would, therefore, be helpful in producing more food for animals and enhancing soil fertility.

Continuous cereal cropping depletes soil fertility. Legumes, however, in ley farming vary in their capacity of fixing nitrogen. Lucerne and clovers enrich the soil nitrogen appreciably, while soybeans and beans grown for seed had little effect on the soil nitrogen. The land laid down to grass could accumulate nitrogen even if the pasture has no legumes. Legumes alone can accumulate much more nitrogen as compared to grasses in a definite period of time.

Leaf, stem and root stubbles of plants contribute organic matter to the soil. Fibrous and deep growing roots of grass and legumes increase organic matter appreciably. Perennial grasses contribute glue like material as root exudates. Microbe in the rhizosphere converts them into organic colloids, endowed with cementing properties. Upon their death the initial decomposition products give again a cementing organic material.

A combination of lucerne and quack grass increase the organic matter content of a chernozem soil from eight to 8.6 per cent after one year and to 8.9 per cent after two years. In another study, one year of growing a grass legume mixture, the organic matter content increased by 0.3 to 0.6 per cent.

Roots of grass or grass legume sod improve soil structure through one of the following mechanisms: pressure exerted by growing roots, which affects a separation of particles adjacent to the roots and a pressing together of these particles into aggregates; granulation accomplished by changes in moisture in the vicinity of the root system as a result of water intake by the plant, which produces localised dehydration, bringing about shrinkage and surface fracture; production of organic colloids during root decomposition serving as stabiliser of soil granules.

Water stable aggregates are remarkably increased due to annual grass and legume/Napier mixture as compared to fallow plots. Organic matter added by roots and stubble residue is responsible for the improvement of soil aggregates. It was observed that soil aggregates were increased by addition of compost and farm yard manure in the soil. Besides depleted soil fertility, monoculture for several years also predisposes crops to attack of insect pests and diseases, which multiply on their favourite food crop year after year.

Therefore, it becomes necessary to alter the cropping pattern to get rid off them. Wheat in continuous cereal rotation was severally affected by “Take all” disease, the ley systems were the most effective in controlling this disease. Ley acts as ‘break’ to control pests and diseases of arable crops. Yields in arable cropping system, as compared to ley system, were lowered only by incidence of potato root eel worm, which has reached a high level of infestation on some of the arable plots.

Ley systems are more profitable than continuous cropping. As the intensity of ley increased, the profit per year is also enhanced. When the land is put under ley, cost of cultivation is low due to reduced cultivation operation, unlike cultivation of cereal crops, where these costs are considerable.

Having an experience of ages, the people of Balochistan are utilising this system which is a profitable, eco-friendly and very relevant to the arid and infertile soil profile to achieve progress. The technology is not specific for the undermined areas and ecosystems, so it is to be adopted everywhere to raise the outputs for the betterment of socio-economic conditions of the farming community.