Nitrogen mineralization controlled by N/P ratio of plant residues from riparian buffer strip

摘要: Soil nitrogen (N) transformation rates are mostly likely related to chemical composition and element ratio of plant residues while contradictory results also reported. We conducted a laboratory incubation experiment for 100 days under controlled conditions (25 °C 50% water holding capacity) investigate the relationship between N mineralization initial characteristics 11 diverse from riparian buffer strip Danjiangkou Reservoir. The had wide range N, cellulose (CE), hemicellulose (HC) lignin (LG) contents, carbon/N (C/N), N/phosphorus (N/P), LG/N CE/N ratios. A principal component analysis (PCA) showed that mean content was negatively associated with LG LG + CE contents highly positive correlated C/N Net ranged widely (5.1–120.3 mg N kg−1 soil) (r2 = 0.71, P < 0.01), (r2 = 0.72, P < 0.001) N/P (r2 = 0.76, P < 0.001). critical levels, i.e. break point net immobilization were 9.4 g kg−1 content, 212.9 g kg−1 343.3 g kg−1 4.1 ratio, 43.8 16.5 19.9 34.6 (LG + CE)/N residues, respectively. multiple regression model demonstrates be most important factor predication effects residue on soil mineral dynamics.