CO2 Evolution and Phosphorus availability in Sandy Loam Soil as Influenced by Levels of Poultry Litter and Peanut Hull Char Mixture

Soil management practices like increasing soil organic carbon content by application of organic material like biochar and improving soil biodiversity can play an important role in sequestering C in soil. Twenty eightdays of incubation experiment was conducted to determine the effects of biochar on CO2 evolution andsoil chemical properties of sandy loam soil. There were 7 treatments (T1 = Control, T2 = 50 g PLC kg-1 soil, T3 = 50 g PHC kg-1 soil, T4 = 40 g PLC + 10 g PHC kg-1 soil, T5 = 30 g PLC + 20 g PHC kg-1 soil, T6 = 20 g PLC + 30 g PHC kg-1 soil and T7 = 10 g PLC + 40 g PHC kg-1 soil which were laid out in RCBD with three replications. The results showed that application of biochar enhances microbial respiration but there were no significant differences between the treatments (P < 0.05) on the CO2 evolved in sandy loam soil for about 28 days of incubation experiment. Some chemical properties of sandy loam soil after the incubation experiment such as soil pH, % organic carbon and extractable P were significantly increased by the application of different proportions of biochar (P < 0.05). However, the addition of different proportions of biochar (T4, T5, T6, and T7) and biochar alone (T2, T3) resulted in lower soil pH than the control (T1) due to the production of NH4+, CO2 and organic acids during microbial metabolism. The result of the experiment revealed that addition of 30g PLC Kg-1 soil + 20g PHC Kg-1 soil could enhance microbial respiration and promote nutrient availability in sandy loam soil.

Keywords –CO2 evolution, Phosphorus, sandy soil, biochar