Abstract:
Properties of biochar prepared from Acacia wood and coconut shell by slow pyrolysis under nine different conditions (pyrolysis temperature was varied from 300-500 oC, pyrolysis time was varied from 1-3 hours) have been investigated in order to identify the suitable initial biomass of biochar applied for sandy soil in rain shadow applicate and increase sesame yield using respond surface method (RSM). Properties of Acacia wood biochar indicate it is more suitable than coconut shell biochar to be applied as sandy soil amendment due to its higher surface area, higher CEC, and slightly lower pH. The optimum condition for preparing Acacia wood biochar using the laboratory electrical furnace is at 434.8 OC and 1 hour of slow pyrolysis time. The prepared Acacia wood biochar was mixed with Huaysai soil for planting sesame. A complete Randomized Design (CRD) was used with 5 replicates and 10 treatments consisting of; Huaysai soil (control), soil with chemical fertilizer (CF), soil with 5% biochar (BC1), soil with 10% biochar (BC2), soil with 15% biochar (BC3), soil with 20% biochar (BC4), soil with CF and 5% biochar (CFBC1), soil with CF and 10% biochar (CFBC2) soil with CF and 15% biochar (CFBC3), soil with CF and 20% biochar (CFBC4) was applied. Sesame was planted for 3 crops. The results showed that the growth and yield of sesame in crop 1 was obviously higher than crop 2 and crop 3. In addition, the yield of sesame in crop 2 and crop 3 was not significantly different at 95% confident interval. Furthermore, CFBC2, CFBC1, and CFBC3 showed the highest growth and yield of sesame in crop 1. It can be concluded that both 5-10% by weight of biochar and chemical fertilizer should be applied to sandy soil in order to increase sesame yield. The overuse of biochar ratio can decrease sesame yield.