Agricultural use of municipal solid waste on tree and bush crops

The effects are evaluated of agricultural applications of compost from municipal solid waste (MSW) to tree and bush crops. Eight experimental plots were established in 1993 and 1994 on agricultural soils of Cordoba in South West Spain. The crops included in this study were vines and olive (rainfed), and citrus (irrigated). Preliminary results of this study showed that application of MSW improved the fertility of the soil. In the case of olive plantations there was an average increase in yield of around 50%, but oil yield (%) and olive fruit mass were not affected. The application of compost to vine in doses of 30 t/ha produced an average increase in yield of 30%, with no change in Baume degree. The increase in yield of citrus fruits was around 17%. Leaf analysis was used to study the nutritive condition of the crops, and significant differences were found in olive and vine leaves in the year following application of MSW to the soil. Drought, which has been suffered for the last few years, may have influenced the results, together with the usual slow response of woody crops to fertilizers. (C) 1997 Silsoe Research Institute.