Effect of Biochar Soil Amendment on Soil Properties and Yield of Sesame Varieties in Lafia, Nigeria

The experiments were conducted during 2011 and 2012 rainy season at the research and teaching farm of the college of agriculture, Lafia, Nasarawa state, Nigeria; to evaluate the effect of biochar amended soil on soil properties and yield of sesame varieties. The treatments consisted of three rates of rice husk biochar (0, 5 and 10 t/ha) and three rates of sawdust biochar (0, 5 and 10 t/ha) and two varieties of sesame (Yandev 55 and local variety) which were factorially combined and laid in a Randomized Complete Block Design (RCBD) and replicated three times. The result showed that the soil is low in major nutrients before the incorporation of biochar. The soil was also acidic in nature (pH: 5.98). After incorporation of biochar and two y ears of cropping. Result revealed that both rice husk and sawdust biochars rates did not showed any significant effect on sand, clay and silt; but had a significant effect on % soil moisture content, bulk density, % porosity and % soil water-filled pore space. Application of 10 t/ha produced the highest value of 10.697% and 10.77% soil moisture content, 36.47% and 35.58% of soil porosity, 50% and 50.6% soil water filled pore space in both rice husk and sawdust biochar. This is at par with application of 5 t/ha of both biochars, but it is higher than the control treatment. However, bulk density decreases with increased rates of biochar application. Therefore, the control produced soils with the higher bulk density of 1.67 g/cm3 and 1.69 g/cm3 with rice husk and sawdust biochar respectively. Also, Rice husk and sawdust biochars rates had a significant effect on all the chemical properties in the soil. 10 t/ha of rice husk and sawdust biochar produced the highest levels of pH, = 6.80:6.74; %TN, =0.15: 0.14; K, =0.59: 0.65; %OC, = 0.68:0.75; Mg, = 0.75: 1.14; Na = 0.71:0.79 and CEC= 7.83:8.05, respectively. This is at par with application of 5 t/ha, but higher than the control. Increased biochar application resulted in a gradual increase in all the chemical properties in the soil except H+Al which displayed an opposite trend. Application of 10 t/ha of sawdust and rice husk biochar produced the highest seed weight of 0.93: 0.83 t/ha and 0.90:0.95 t/ha in both years, respectively. This is at par with application of 5 t/ha of both biochars in the two cropping season, but higher than control. Sesame varieties also showed a significant effect in both cropping season; Yandev 55 demonstrated its superiority against the local variety by producing 0.76 t/ha and 0.77 t/ha in 2011 and 2012 cropping season. However, the combine effect of sawdust biochar and rice husk biochar did not produce any significant effect on the soil properties and sesame yield.