Phosphorus Transformation in Biochar and Poultry Litter Amended Soils.

Biochar is considered as a promising soil amendment to sequester atmospheric carbon as well to enhance crop productivity by improving soil physical, chemical, and biological properties. Current interest in biochar as a soil amendment is mainly due to its potential to sequester atmospheric carbon and to mitigate climate change. The concurrent benefits of biochar amendments include improved soil fertility, crop yields, and reduced nutrient leaching This study is focused on preliminary investigation of utilizing biochar as a P source in P deficient soils in southeastern US. Laboratory incubation studies were performed to study the possible P transformations in biochar amended soils with time compared to poultry litter amended soils. Biochar treated and untreated soils were analyzed for pH, CEC, Mehlich 3 extractable P after incubation for specific times. Soils were also subjected to a P fractionation method which allowed quantification of changes in water soluble P, labile P, Fe/Al oxide bound P, Ca bound P, and residual P. The study will generate preliminary information pertaining to transformation of P forms in biochar amended soils due to changes in soil pH and activity or availability of cations such as Al, Fe, and Ca. It will also provide information on possible use of biochar amendments for P mitigation in manure applied soils.