Effects of biochar amendment in soils from Kisumu, Kenya

Abstract: Agriculture in Kenya consists mainly of smallhold farming that produce the majority of the total agricultural products. Until the late 1900s soil fertility was maintained through good farming practices with fallow periods, crop rotations and fertilization with livestock manure. Due to the increasing demand for food and the scarcity of land the present agricultural production cannot maintain these practices. Agricultural land is therefore losing soil fertility as most farmers cannot afford to buy fertilizers and often lack the knowledge of other alternative practices. A possible measure to increase soil fertility and carbon content is by biochar amendment. Biochar is produced through pyrolysis, a process when organic material is turned into carbonaceous material during heating with low to no access of. Biochar consist of both stable and easy degradable parts. This is a Minor Field Study concerning biochar amendment in smallhold farming where the maize mixed farming system is utilized. The aim was to examine the effect of biochar as a soil amendment on decomposition of organic matter and on plant growth of maize under varying soil moisture conditions in Kisumu, Western Kenya. Soils from two nearby farms were used in a pot trial. The results from soil analyses showed that the amendment of biochar significantly increased pH, carbon content, the total amount of magnesium and calcium in both farms. I the plant growth trial with a water level of 90 % of field capacity there were no significant differences between the control and biochar treated soil, but both trial showed signs of nitrogen deficiency. For the plant trial with 40 % of field capacity both the control and biochar treated trial showed signs of drought stress but it were more severe in the control than in the biochar treated.