Effects of agricultural wastes ash on nutrients concentration and yield of maize (Zea mays l) in Haplic Acrisol of Southeastern Nigeria

Abstract

Field trials and a pot experiment were conducted during the 2005 and 2006 cropping seasons at Michael Okpara University of Agriculture, Umudike, Nigeria, to assess the effect of various agricultural wastes ash on nutrient concentration, growth and yield of maize in a Haplic Acrisol. The treatments comprised palm bunch ash, kitchen residues ash, cocoa pod husk ash, saw dust ash, calcium carbonate, oyster shell ash and a control. Each of the ash was applied at five levels: 0, 2, 4, 6 and 8 tonnes per hectare. They were replicated three times in a split plot completely randomized design for the pot experiment and randomized completely block design for the field trials. The effects of the treatments were measured on nitrogen, phosphorus, potassium, calcium, and manganese and iron concentration in maize crop. Other plant parameters measured were maize height at 8 weeks after planting, stem diameter, stover weight and grain yield weight in the field trails. The results obtained showed that all the agricultural wastes significantly (P < 0.05) increased the concentrations of nitrogen, phosphorus, potassium and calcium. They also significantly (p<0.05) reduced the concentration of iron and manganese in the plant. The wastes applied significantly increased the plant height at 8 WAP, maize stem diameter, stover weight and grain yield. Among the treatments tested, 6t/ha of cocoa pod husk ash significantly (P<0.05) increased nitrogen concentration in the maize from 0.49 in the control to 5.17%. Plant height, stem diameter and stover weight were also increased by the application of 6t/ha of cocoa pod husk ash. While 4t/ha of kitchen residue ash, 4t/ha of oyster shell ash and 4 t/ha of cocoa pod husk ash significantly (P<0.05) increased the concentration of phosphorus from 1.01% to 4.98%, calcium from 0.4% to 6% and potassium from 0.19% to 0.42% respectively. The soil pH correlated negatively with iron and manganese concentration, positively with phosphorus and calcium concentration. These results show that maize can be grown successfully on Haplic Acrisol of the Southeastern Nigeria using waste from agricultural products.

Key words: Agricultural wastes ash, nutrient concentration, growth, grain yield, HaplicAcrisol