Conservation agriculture, improving soil quality for sustainable production systems?

Abstract

Human efforts to produce ever-greater amounts of food leave their mark on the environment. Persistent use of conventional farming practices based on extensive tillage, especially when combined with removal or in situ burning of crop residue, has magnified soil erosion losses and the soil resource base has been steadily degraded. It has been estimated that human activity is responsible for the loss of 26 billion tons of topsoil per year, which is 2.6 times the natural rate of soil degradation. Erosion has been estimated to cause USD $44 billion a year in damage to farmland, waterways, infrastructure, and health. Crop yields in the US would drop 8% per year if farmers failed to replace lost nutrients and water (Pimentel et al., 1995). Another direct consequence of farmers’ persistent use of traditional production practices is rapidly increasing production costs; the costs of inputs such as improved varieties and fertilizers continue to increase and farmers make inefficient use of them.