ABSTRACT
Agriculture is the means of ensuring household and national food security and a driving force for economic transformation. Sustainable agriculture is aimed at improving the productivity of smallholder agriculture through adopting soil and water conservation techniques. This contributes to food security in the country. Sustainable agriculture is increasingly gaining recognition in southern Africa as involving a group of technology interventions that have the potential to increase yields from a wide range of crops, through the conservation of soil, water, nutrients, and farm power.
Water and soil nutrient management form a critical component of agricultural production. The most important constraints to rain-fed crop production are drought and poor soil fertility. Secondary factors that worsen the food security plight among poor and vulnerable members of the smallholder farming community that are usually assisted by relief organizations include late planting as a result of lack of draft power for timely tillage and poor access to inputs like manure and fertilizer to ameliorate the effects of exhausted soils with low organic matter content on crop growth and yield. To improve crop production in marginal rainfall regions, cultural practices that conserve and extend the period of water availability to the crop are essential, if the full benefits of soil fertility improvements through organic and inorganic fertilizers are to be realized.
Thus, sustainable agriculture is needed to develop farming systems that are productive and profitable, conserve the natural resource base, protect the environment, and enhance health and safety, and to do so over the long term. It aims at achieving creative and innovative conservation and production practices that provide farmers with socially acceptable, economically viable, and 332environmentally sound alternatives or options in their farming systems. Climate and soil are the two most critical factors that determine the ultimate sustainability of agricultural systems. As temperature increases and precipitation decreases, the development of sustainable farming systems becomes difficult. The potential for erosion by water and wind also tends to increase with increasing temperatures. Both these degradation processes progressively accelerate with increasing aridity because of the associated decline in soil organic matter and less natural vegetation to control erosion. This chapter focuses on strategies to improve rainfall management in sustainable agriculture practices.
