Effect of Biochar on Soil Properties and Organic Carbon Sink in Degraded Soil of Southern Guinea Savanna Zone, Nigeria

Abstract

Biochar incorporation into soil has been shown to improve the soil quality for crop production and sequestered organic carbon into the soil thereby mitigating climate change. The experiment was conducted during 2010 rainy season at the research and teaching farm of the college of agriculture, Lafia, Nasarawa state, Nigeria. To evaluate the effect of biochar on soil properties and the amount of organic carbon that can be sequestered in the soil. The treatments consist of biochar rates: 0, 5 and10t/ha laid in Randomized Complete Block Design (RCBD).10t/ha of biochar produced the highest levels of (pH, = 6.91; %Total Nitrogen, =0.38; K, =1.59; %Organic Carbon, = 0.56; Mg, = 2.50 and Cation Exchange Capacity = 11.35) compare to the other rate and control. However, application of 5t/ha of biochar did not show any significant effect compared with the control. Biochar application did not show any significant effect on sand, clay and silt; but had a significant effect on % organic matter, bulk density and %porosity. Application of 10t/ha of biochar produced the highest value of 7.67% silt and clay; but sand particles and bulk density decreases with increased rates of biochar application. Therefore, the control produced soils with the highest values of sand particles of 87.33% and bulk density of 1.68g/cm. Also, there is a significant difference in total quantity of carbon sequestered at the different rates of biochar application. 10t/ha sequestered a largest quantities of 1352.40t/ha of soil organic carbon. The lowest carbon stored of 926.85t/ha was reported in control plot. The result of this study suggest that biochar additions to the soil produced general improvement of soil qualities, with the possibility of lowering the soil acidity and increasing organic matter and organic carbon sink which has the capacity to improve crop production and mitigate climate change.