Abstract

The paper reviews and analyzes agricultural resource problems and management strategies in the tropics, as identified and recommended by ecologists, soil and land management specialists, biological and chemical scientists, meteorologists, and conservationists. The rapid increase in atmospheric concentration of CO2 and other greenhouse gases like methane and dinitrogen oxide since about 1850 has been partly due to inappropriate agricultural management practices. If the concentrations are not controlled or reduced, they could lead to significant global warming and climate change. The application of appropriate agricultural conservation methods will result in the enhancement of tropical ecosystems as sinks of atmospheric carbon, reduction in the rates of emission of carbon dioxide, methane, and other greenhouse gases from these ecosystems to the atmosphere, and the realization of certain ecologically beneficial processes such as the sequestration of carbon in tropical soils which will help reduce atmospheric carbon levels. Sustainable and productive measures to control or reduce greenhouse gas emissions from tropical agricultural ecosystems into the atmosphere were also discussed in this paper. They include the restoration of organic matter to the soil through additions of crop residue mulch, farmyard manure, compost, etc. to the soil; growing leguminous and cover crops; addition of plant nutrients through chemical fertilizers and organic amendments; and use of less intensive tillage practices. In tropical grazing systems, introduction of exotic pasture species, especially legumes, have enhanced pasture productivity of grasslands and often resulted in increased organic carbon in the soil. In addition, improved pasture productivity through fertilizer inputs, renovation, reducing stocking rates, and eliminating or reducing the incidence and frequency of veld fires are necessary for increasing organic carbon in the soil. Poverty reduction should also be a critical component of action to reduce greenhouse gas emissions and support mitigation of climate change.