Utilising agricultural waste to enhance food security and conserve the environment

The rapid increase in the world's population coupled by urban migration has resulted into an increased demand for food which has in turn led to the production of large amounts of agricultural wastes, both at the farmer, municipality and city levels. The bulk of the agricultural food in developing countries is transported to cities in its raw forms, thus compounding the net effect on large deposits of waste in urban markets, around homes and in slums as well as in various dumping grounds. In Kampala alone, over 1000mt of waste accumulate in the city and only about 30% of it is collected by the City Council leaving the rest to rot and pollute the environment. Although it is recognized that the accumulation of waste has enormous ill effects on humans and the environment, such wastes, if properly managed could be considered an important bio-resource for enhancing food security in the small holder farming communities that would not afford use of expensive inorganic fertilizers. These organic wastes contain high levels of Nitrogen, Phosphorus, Potassium and organic matter important for improving nutrient status of soils in urban agriculture. Various factors amplify the agricultural waste problem, especially in developing countries where there are limited waste recycling facilities. Most of the nutrients are leached from the dampfills and end up polluting water bodies and this has been associated with the invasion of water weeds. Most importantly, there is lack of planning, poor public awareness, poor government policy and laws, and lack of or insufficient utilization of resources. In Kampala, many small holder farmers have improved milk production by feeding animals with various combinations of agricultural wastes. Others have increased nutrient supply in soils by applying organic compost leading to improved crop yields, especially vegetables and maize which fetch high prices for the farmers thus reducing poverty levels and enhancing food security. This alternate method of removal of these wastes for agricultural production by farmers has also reduced the rate of accumulation with subsequent reduction on environmental pollution thus improving on environmental health. This paper briefly reviews how agricultural wastes can be used to enhance food security and conserve the environment.