Demand-Driven Technologies for Sustainable Maize ... - IITA

125Farmers in Nigeria use a wide range of locally derived organicmaterials for soil management, principally in the form of crop residuesand animal manure. Other materials such as prunings from trees,green manure, industrial wastes, municipal wastes, and sewage sludge,have not been extensively used in the Nigerian savanna because ofproblems with collection, processing, transportation and application.The objective of the present study was to determine the effect ofcow dung, maize crop residue, Mucuna pruriens vines and Leucaenaleucocephala prunings on the response of extra-early maturing maizeto inorganic fertilizer in the Nigerian savanna.Materials and MethodsField experiments were conducted during the cropping seasons of1998, 1999 and 2000 on a sandy loam soil (Alfi sol) at the researchfarm of the Institute for Agricultural Research (IAR), Zaria, Nigeria(lat 11 0 11’N, long 7 0 38’ E and altitude 686 m asl). The fi eld waspreviously cultivated to Vigna unguiculata (L.) Walp and left to fallowfor three years, a typical practice of farmers in the northern Guineasavanna of Nigeria. Rainfall distribution at this location is characterizedby distinct wet and dry seasons in alternation (Fig. 1).The treatments consisted of factorial combinations of four differentorganic material sources (cow dung, maize stover, L. leucocephalaprunings, M. pruriens vines, applied at 5 t ha -1 each), four rates ofchemical fertilizer treatments (0, 25, 50 and 100% recommendedrates of NPK), and a control. The current fertilizer recommendation foropen-pollinated maize in the Nigerian savanna is 120-60-60 N, P 2O 5,and K 2O kg ha -1 . The cow dung was obtained from dairy cattle at theNational Animal Production Research Institute, Shika, Nigeria.The maize stover, M. pruriens vines and L. leucocephala pruningsused in this study were obtained from research fi elds of the Institute forAgricultural Research, Zaria, Nigeria. Daudu et al. (2005) have reportedin greater details the methodology, including the chemical properties ofthe organic materials. Equivalent amounts of the organic materials on dryweight basis, corresponding to 5000 kg ha -1 were applied as appropriateand properly incorporated into the soil before ridging. Similarly,phosphorus levels (P 2O 5) at 0, 25%, 50% and 100% recommended ratesof single super-phosphate were also applied on the appropriate plotsbefore ridging. Potassium levels of muriate of potash (K 2O) and the fi rstsplit (dose) of nitrogen (urea at 0, 25, 50 and 100% of the recommendedrate) were applied at planting using factorial arrangement. The secondsplit dose of N was applied at 4 weeks after planting. The study wasconducted on the same site and treatments were repeated on the sameplots in each of the three years. In the fi rst year, the fi eld was ploughed,harrowed and ridged using a tractor, while in the second and third years