Magnesium-doped biochars increase soil phosphorus availability by regulating phosphorus retention, microbial solubilization and mineralization

作者：Muhammed Mustapha Ibrahim, Huiying Lin, Zhaofeng Chang, Zhimin Li, Asif Riaz, Enqing Hou · 发表于：Biochar · 年份：2024 · DOI：10.1007/s42773-024-00360-z · 被引用次数：29 · 研究领域：Phosphorus and nutrient management、Soil Carbon and Nitrogen Dynamics、Soil and Water Nutrient Dynamics

Abstract Despite fertilization efforts, phosphorus (P) availability in soils remains a major constraint to global plant productivity. Soil incorporation of biochar could promote soil P availability but its effects remain uncertain. To attain further improvements in soil P availability with biochar, we developed, characterized, and evaluated magnesium-oxide (MgO) and sepiolite (Mg 4 Si 6 O 15 (OH) 2 ·6H 2 O)-functionalized biochars with optimized P retention/release capacity. Field-based application of these biochars for improving P availability and their mechanisms during three growth stages of maize was investigated. We further leveraged next-generation sequencing to unravel their impacts on the plant growth-stage shifts in soil functional genes regulating P availability. Results showed insignificant variation in P availability between single super phosphate fertilization (F) and its combination with raw biochar (BF). However, the occurrence of Mg-bound minerals on the optimized biochars’ surface adjusted its surface charges and properties and improved the retention and slow release of inorganic P. Compared to BF, available P (AP) was 26.5% and 19.1% higher during the 12-leaf stage and blister stage, respectively, under MgO-optimized biochar + F treatment (MgOBF), and 15.5% higher under sepiolite-biochar + F (SBF) during maize physiological maturity. Cumulatively, AP was 15.6% and 13.2% higher in MgOBF and SBF relative to BF. Hence, plant biomass, grain yield, and P uptake w...