Animals Are A Crucial Link In Nutrient Cycles

Animals are a crucial link in nutrient cycles, returning nutrients to the soil in forms that plants can readily use. They can bring nutrients from pasture and rangeland and concentrate them on crop land through their manure and urine. The animal manure and urine that people in the developed world see as pollutants are vital fertilizers in the developing world.

Few smallholders can afford enough mineral fertilizers. Animals give farmers a reason to plant legumes as pastures and cover crops that protect the soil and restore its structure and fertility. According to a Winrock report in 1992, `The greatest threat to [the African rangelands] comes from human populations and expansion of cultivation. There is no solid evidence linking livestock to this process [desertification].’

Increasing the productivity of livestock systems and mixed crop-livestock systems motivates farmers to protect their rangelands and use them sustainably for raising livestock rather than putting them to the plough.

Productive livestock can add value to `idle’ land. Already, in many parts of the world mixed crop-livestock systems are the norm, but the importance of the livestock component has been overlooked. Even the language we use tends to reinforce this. When we talk about the non-grain parts of cereal crops, we tend to use terms like `crop residues’ or `by-products’. Yet in many farming systems, such as the barley-sheep system of the drier parts of West Asia and North Africa and the tef-based system in the Ethiopian highlands, the farmers value these `by-products’ as much as, if not more, than the grain. `Improved’ varieties or production packages that overlook the feeding value of these `residues’ will find little favor with the majority of farmers.