Experimental mathod
Five fertilizer treatments included vermicompost (VM), chicken compost (CM), horse compost (HM),chemical fertilizer (CF) and no fertilizer (CK). Warmcast, chicken manure and horse manure were respectively composted with crushed maize straw and rice chaff at the ratio of 1:1:1 to be completely decomposed as vermicompost (VM), chicken-compost (CM) and horse-compost (HM). The nutrient contents in various manures