ORGANIC FARMING SYSTEMS IN ZAMBIA

摘要

About 70 percent of Zambia's working population is engaged in agriculture, largely subsistence farming. The agricultural sector accounts for 20 percent of the country's gross domestic product (FAO, 2006). This sector however, faces numerous challengesranging from declining soil fertility, lack of high quality germplasm, inadequate rural infrastructure, extreme weather conditions and unsupportive policies (Keil er al, 2004). Declining soil fertility is one of the greatest of these constraints to increasing and sustaining agricultural productivity, especially among smallholder farmers (Vanlauwe and Giller, 2006). This is primarily caused by three interlinked factors: a breakdown of the traditional fallow system as a result of an increasing populationand decreasing per capita land availability (Kwesiga ef al, 2003); inadequate adoption of sustainable soil fertility management options; and sub-optimal use of mineral fertilizers by the majority of smallholder farmers due to high cost and supply difficulties (Howard and Mungoma, 1996). With this background it is clear that the standard mineral fertilizer-seeds subsidy alone will not sustainably increase agricultural productivity especially among smallholder farmers in Zambia.Long-term improvement in soil fertility has become a very important issue in the research and development agenda (Scoones and Toulmin, 1999) because of the strong linkage between soil fertility and food insecurity and the implications to the economic well-being of the country (Ajayi ef al., 2007).