Phosphorus availability in soils amended with wheat residue char

• Published in: Biology and fertility of soils 2013-02, Vol.49 (2), p.245-250
• Main Authors: Parvage, Mohammed Masud, Ulén, Barbro, Eriksson, Jan, Strock, Jeffery, Kirchmann, Holger
• Format: Article
• Language: English
• Subjects: Agricultural land; Agriculture; Agronomy. Soil science and plant productions; Biological and medical sciences; Biomedical and Life Sciences; Charcoal; Clay loam; Crop residues; Environmental Sciences related to Agriculture and Land-use; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Leaching; Life Sciences; Miljö- och naturvårdsvetenskap; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Phosphorus content; Short Communication; Silt loam; Soil amendment; Soil conditioners; Soil fertility; Soil science; Soil Science & Conservation; Soil sciences; Soil solution; Soil texture; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Wheat
• ISSN: 0178-2762; 1432-0789; 1432-0789
• DOI: 10.1007/s00374-012-0746-6

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, P concentrations decreased which coincided with a pH increase of 0.3–0.7 units. When the 11 soils were amended with 1 % ( w / w ) biochar, water-soluble P concentrations increased in most of the soils ranging from 11 to 253 %. However, much of the water-soluble P added through the biochar was retained (33–100 %). We concluded that wheat residue char can act as a source of soluble P, and low and high additions of biochar can have different effects on soil solution P concentration due to possible reactions with Ca and Mg added with biochar.