Integrated Manure and Fertilizer Use, Maize Production and Sustainable Soil Fertility in Sub Humid Zone of West Africa

摘要

In the sub-humid zone of northern Ghana, maize is a high rated crop and farmers use various technologies for soil fertility maintenance and to increase grain yield. Technology chosen usually depends on the resources available to the farm household. Weconducted a three-year field study (1996-1998) at Nyankpala, Ghana in the sub humid zone of West Africa. The study evaluated the effect of manure applied at 0, 4 and 8 t ha~(-1) with or without inorganic fertilizer at suboptimal rate of 60-17.5-33 kg ha~(-1) N-P-K, respectively. Corn yield was increased from 55.6% in 1996 more than 120% in 1998 because of manure application compared with corn yield from control. Application of manure plus fertilizer resulted in significant corn yield increases over thecontrol. Manure plus fertilizer application resulted in increased fertilizer use efficiency compared with application of fertilizer alone. Sustainability yield index, a quantitative assessment of yield sustainability overtime, was highest with manure plus fertilizer. Soil fertility indicators such as soil organic carbon, cation exchange capacity and soil pH improved with repeated manure application.