Crop variety mixtures in marginal environments

Intensive agriculture supported by good infrastructure has in recent decades come to be associated with uniform monocultures of crop varieties. These varieties are chosen for their characteristics of adaptability and stability under conditions of high inputs of labor and chemicals. As a result significant widespread increases in yield and harvest stability have been achieved. Yet in marginal environments the situation is quite different. Here the variability between production sites is high, climatic conditions are erratic within seasons and between years, and infrastructural development is poor. Farmers often respond by enhancing diversity, both of crops and varieties of crops. Diversity allows versatility; it also contributes to greater household security.