Effect of Biochar, Farmyard Manure and Nitrogen Fertilizers on Soil Chemical Properties in Sinana District, South Eastern Oromia, Ethiopia

摘要

Integrated soil fertility management could be a useful tool to maintain and improving soil fertility. Therefore, the experiment was conducted with the objective of investigating the influence of biochar, farmyard manure, and mineral nitrogen fertilizer on soil chemical properties. The disturbed soil samples were collected from five locations of each plot at optimum moisture conditions to a depth of 20 cm at the start of the experiment, after six months of farmyard manure and biochar treatments application. The treatments consisted of two levels of farmyard manure (0 and 6 tons ha~(-1)), three levels of biochar (0, 5, and 10 tons ha~(-1)) and three levels of nitrogen (0, 23 and 46 kg N ha~(-1)). The results revealed that the interaction effects of biochar, farmyard manure, and mineral nitrogen fertilizer significantly (P<0.001) influenced the soil chemical properties of major contents of soil available potassium, nitrate nitrogen and ammonium nitrogen after six months. Similarly, the analysis of variance showed that the interaction effect of biochar and farmyard manure levels significantly (P<0.05) influenced soil reaction (pH) and CEC. However, the interaction effect of biochar, farmyard manure and nitrogen levels and that of farmyard manure and biochar levels as well as biochar and nitrogen levels on soil available phosphorus were non-significant. Generally, the availability of plant nutrients concentration in the soil solution before treatments of farmyard manure and biochar application was lower than that of after six months. Likewise, farmer should be advised to add small amount of mineral fertilizer to farmyard manure and biochar to improve soil properties and enhance soil productivity and quality.