Effects of Humic Material, Compost, Chicken Manure, Deetoka, Vigriphol, Agrostemin, and Chemical Fertilizers on Corn, N-fertilizer Efficiency and Soil Hardness

Abstract

An experiment was conducted using large pots and low-fertility soil to compare the effects of humic material, compost, chicken manure, Dectoka, Vigriphol, Agrostemin and foliar chemical fertilizers on corn, the efficiency of N from urea and soil hardness. Planting was done in three successive croppings. The humic material at 42.5 1 ha^-1 and the vompost at 6.25 ha^-1 when applied alone were equally effective but superior to low-rate chemical fertilizer in their growth-promoting on corn. However, chicken manure at 6.25 t ha^-1 was about twice as effective as those two materials. The humic material, compost, Deetoka, Vigriphol, Agrostemin, foliar K fertilizer and foliar NPK fertilizer, when applied in combination with adequate rate of chemical feritlizers, were not effective in promoting growth of corn plants whereas chicken manure when applied in combination with adequate-rate chemical fertilizers were much less effective than when applied alone. The growth-promoting effects of humic, compost and chicken manure were primarily due to the supplies of the fertilizer elements thereof. The humic material was more effective in decreasing soil hardness than the compost and the chicken manure. The humic material, compost, Deetoka, Vigriphol and Agrostemin did not affect the assimilation of mineral N in soil whereas chicken manure reduced the assimilation of mineral N in soil through dilution effect of mineral N released thereof. Considering both the cost of materials and crop response, chicken manure should be most recommended to use for corn production.