Potential effects of biochar on the availability of phosphorus — mechanistic insights

摘要: Abstract Potential supply shortages of phosphorus (P) rock reserves call for a more efficient use P fertilizer and exploring new ways recycling the nutrient within agro-ecosystems. Conditioning arable land with biochar might contribute to achieving both goals. We examined three putative mechanisms governing availability in amended soils. direct inputs from eight biochars differing feedstocks production techniques were assessed using sequential fractionation. Phosphorus sorption on one pyrochar hydrochar was also studied. Finally, competitive between biochar-derived dissolved organic matter (DOM) goethite studied at pH levels. Total varied 0.6 4.0 mg g − 1 derived phytomass, 47 mg sewage sludge. In two slightly acidic hydrochars most 0.1 M NaOH extractable, Fe-associated, while remaining alkaline pyrochars 1 M HCl Ca-associated. Biochar intrinsic mostly intermediate stability slowly replenish labile Both weak sorbents phosphate. show that DOM released biochar, however, can inhibit depending initial pH, ratio order sorbate addition. Strong competition biochar-DOM sites especially low values suggests enhance efficiency acidic, highly weathered strongly fixing