Access to institutional credit sources is limited, and marketing restrictions reduce the profitability of some crops. On the other hand, government policies have made oilseeds more profitable, greatly benefiting farmers in the semiarid tropics. Infrastructure investments have generated marketing opportunities for these crops and also for milk, whose production has flourished under village-based marketing cooperatives. Soil nutrient deficits are widespread on rainfed land. Irrigated plots received most of the available manure and most fertilizer.
Soil erosion is also widespread.
Soil conservation programs have had limited impact, mainly because recommended practices were incompatible with existing farming systems. Farmers have indigenous methods to control erosion, but they often fail to adopt these methods because they are not profitable and because of factors such as short-term tenancy contracts and credit market restrictions. Investment is higher on irrigated plots because water management practices also have soil conservation benefits. Water may be the key to sustainable intensification of agriculture in the semiarid tropics, because farmers manage their soil better on irrigated plots. However, water sources are scarce and subject to degradation.