In northern Pakistan and Nepal, field trials have shown widespread nitrogen (N) deficiencies in rain-fed cereal crops. Potential yields based on known water-use efficiencies (WUE) are 23 times higher than those in rain-fed which were (0.9 t/ha for wheat in northern Pakistan; 1.4 t/ha for cereals in Nepal). Economic pressures prevent the optimal use of N fertiliser.

Legumes fix atmospheric N which allow them to grow in N-impoverished soils, and the root nodules and plant remains after harvesting help replenish the soil. When cereals are grown in rotation with legumes, yields almost always increase - often by as much as 80%. Reduction in diseases and pests and improved soil structure also follow.

Legumes have been used extensively in the western and southern regions of the Australian cereal belt since the 1980s, but in the northern cereal belt of eastern Australia farmers prefer to grow cereals to the exclusion of legume crops and use little N fertiliser.