Effect of different levels of bio char, cattle manure and npk fertilizer combinations on maize yields in Bbamba-kiteezi wakiso district

Abstract

Soil nutrient depletion is a major constraint to maize production in Uganda, especially following the release of high yielding varieties like DKC9089 which was not backed by fertilizer recommendations needed to sustain high yields. Hence farmers’ yields have continued to decline averaging to 1.5t ha-1. A study was conducted to determine the effect of different levels of biochar, in combination with cattle manure, and NPK in closing the yield gap of maize, during the first rain season of 2019 in Bamba - Kiteezi, Wakiso district, in central Uganda. The experiment was laid in Randomized Complete Block Design (RCBD) with three replicates. Each block contained nine plots to accommodate the treatments which were; biochar + cattle manure, cattle manure + NPK, biochar + cattle manure + NPK, and control. Data was collected at an interval of 3, 5, 7, 9, 11, and 13 weeks from planting. Data collected was on growth and yield parameters; leaf area index, leaf length, leaf width, number of leaves, plant height, stem girth, number of cobs, ear diameter, ear length, number of lines per ear, weight of 100 seeds and yield. Analysis of variance (ANOVA) was done to assess the effect of the treatments on growth and yield performance of maize. Results showed that all inputs increased maize growth and yield significantly (p<0.05) in comparison with the control. Different levels of Biochar, cattle manure and NPK (T2, T3, T4, and T9) had a greater effect with highest weight of 100 seeds and mean yield of 10,000 kg/ha while control had the lowest mean yield 0f 7350 kg/ha. Biochar, cattle manure and NPK in combination (T2, T3, T7, and T8) also increased maize growth parameters compared to control. The inputs also improved the soil conditions which was a reflection in the yields obtained. Therefore, the use of biochar, cattle manure and NPK in combination is vital for sustainable production of maize and reduces quantities and costs of other inputs especially of chemical fertilizers.