Effects of Biochar, Rice Husk and Rice Straw on Productivity of Maize (Zea mays L.) and Sustainable Soil Fertility Restoration

Integrated soil fertility management technology fits into the status of resource poor farmers in the Guinea savannah zone of Ghana. A field experiment was conducted at Nyankpala during the 2014 cropping season, to investigate the effects of Biochar, Rice husk and Rice straw and subsequently the residual impact on yield components and grain yield of maize. The study was a 3×3×3 factorial experiment consisting of three organic materials at three levels (2.5, 5 and 7.5 t ha-1 on dry matter basis) and three NPK rates (0-0-0, 45-30-30 and 90-60-60 kg ha-1) laid out in a Randomized Complete Block Design with four replications. The highest grain yield was obtained with 7.5 t ha-1 biochar (4825 kg ha-1) plus at 90-60-60 kg NPK t ha-1, but 7.5 t ha-1 a biochar plus 45-30-30 kg NPK t ha-1 gave similar yield making the dose more acceptable. Longest cob was obtained with 5 to 7.5 t ha-1 of biochar (22.60 cm), or rice husk (20.69 cm), or rice straw (21.45 cm) plus at least 45-30-30 kg NPK ha-1. Shortest days to 50% flowering was found in 5 to 7.5 t ha-1 biochar (48.7), 5 to 7.5 t ha-1 rice husk (49.1) and 5 to 7.5 t ha-1 rice straw (49.6) plus at least 45-30-30 kg NPK ha-1 applications. Overall, organic materials supplemented with NPK fertilizer gave better results than sole organic materials or NPK fertilizer. The correlation coefficient of grain yield with stover weight and 100 seed weight were (r=0.757**) and 100 seed weight (r=0.678**) respectively. Organic materials plus at least 45-30-30 kg NPK ha-1 increased soil organic carbon content (72.8%), Nitrogen (95.6%), Phosphorus (54.6%) and Potassium (17.2%) for maize production.