View article

Plant availability and risk for leaching and/or runoff losses of phosphorus (P) from soils depend among others on P concentration in the soil solution. Water-soluble P in soil measures soil solution P concentration. The aim of this study was to understand the effect of wheat residue char (biochar) addition on water-soluble P concentration in a wide range of biochar-amended soils. Eleven agricultural fields representing dominant soil texture classes of Swedish agricultural lands were chosen. Concentrations of water-soluble P in the soils and in biochar were measured prior to biochar incorporation to soils in the laboratory. Experiments with three dominant soil textures—silt loam, clay loam, and an intermediate loam soil with different rates of biochar addition (i.e., 0.5, 1, 2, and 4 %; w/w) showed that the highest concentration of water-soluble P was achieved at an application rate of 1 %. At higher application rates …