Soil Colloidal P Release Potentials under Various Polyacrylamide Addition Levels

• Published in: Land degradation & development 2017-10, Vol.28 (7), p.2245-2254
• Main Authors: Liang, Xin‐Qiang, Liu, Zi‐Wen, Liu, Jin, Chen, Ling‐Ling, Tian, Guang‐Ming
• Format: Article
• Language: English
• Subjects: anionic polyacrylamide rate; colloidal P; Colloids; Erosion; Loam; Loam soils; Material requirements planning; Molybdenum; Phosphorus; polyacrylamide; release potential; Sandy loam; Sandy soils; Silt; soil colloids; Soil erosion; Soil properties; Soil texture; Texture
• ISSN: 1085-3278; 1099-145X
• DOI: 10.1002/ldr.2752

Anionic polyacrylamide (PAM) can prevent soil erosion, but its effect on fine particulate phosphorus (P), such as colloidal P, has not been thoroughly examined. The effects of PAM on the release potentials of water‐dispersible colloids (WDC) and total P, molybdenum‐reactive P (MRP), and molybdenum‐unreactive P (MUP) in the colloidal and truly dissolved phases (i.e., TPcoll, MRPcoll, MUPcoll, TPtruly, MRPtruly, and MUPtruly) from six soils across South China were tested in this study. The results showed that the release potentials of TPcoll in the control treatments were 6·9–46·1 mg kg−1 and generally highest in sandy loam soil. Following low (12·5 kg ha−1), middle (25 kg ha−1), and high (50 kg ha−1) levels of PAM application, the release potential of TPcoll decreased by 41·7, 63·2, and 77·4% compared to the control group, respectively. Additionally, PAM may trigger MRPcoll and TPtruly releases in sandy loam and/or silt soils, and for most soils, MRPtruly and MUPtruly showed the highest release potentials at middle or high PAM levels. A significant PAM application level by soil site interaction for the release potentials of WDC and colloidal P was observed. Multiple linear regression showed that the PAM rate combined with soil sand content can successfully predict the release potentials of WDC (R2 = 0·552, p