Rice Husk charcoal and its Combined Uses with Conventional Chemical and Organic Fertilizers influencing Corn Growth in Sandy and Lateritic Soils

Abstract

Rice husk charcoal (RHC) used as a soil amending material has potential to improve fertility of degraded tropical lateritic and sandy textured soils. Two greenhouse experiments were conducted to investigate effects of RHC and its combined application with other conventional fertilizers, including chemical fertilizer (CF), cow manure (CM), and compost (CP), on sweet corn growth in the lateritic and sandy soils. In the lateritic soil, RHC produced significantly higher corn shoot dry biomass (2.77 g pot-1) than unamended soil (0.40 g pot-1), while the RHC treatment produced comparable corn biomass to the CF (3.41 g pot-1). Shoot dry biomass of corn under CM (1.14 g pot-1) was not significantly different from that under unamended soil. Meanwhile in the sandy soil, fertilizers in combination with RHC brought about higher biomass than fertilizers applied alone, i.e., CF+RHC (9.25 g pot-1) vs CF alone (6.99 g pot-1); and CM+RHC (4.22 g pot-1) vs CM alone (2.18 g pot-1). Regarding CP, there was no significant difference in corn shoot dry biomass between CP+RHC (4.32 g pot-1) and CP alone (4.25 g pot-1) in the sandy soil. Mechanisms underlying plant negative and positive responses to RHC and the conventional organic and chemical fertilizers were discussed. The use of combination of charcoal with different rates of chemical fertilizer with the aim of lowering amount of chemical fertilizer used is to be further investigated.