pH, nitrogen mineralization, and KCl-extractable aluminum as affected by initial soil pH and rate of vetch residue application: results from a laboratory study

摘要: Initial soil pH determines the direction and magnitude of change after residue addition. This study aimed to evaluate relative importance initial rate application in determining subsequent change, nitrogen (N) mineralization, soil-exchangeable aluminum (Al). An incubation experiment was conducted for 102 days on a Plinthudult Paleudalf soil, where gradients were produced direct current (DC). Rates vetch applications 0, 5, 15, 30, 50 g kg−1 soil. Increasing rates caused greater increases pH, but no consistent increase at higher range (4.40∼6.74), because nitrification. There positive correlation between alkalinity production day 14, while correlations became negative days 56 102. Mineral N accumulated as NH4 +–N low soils, due limited nitrification, NO3 −–N dominated soils. Application decreased KCl-extractable Al, probably complexation Al by organic matter precipitation result increased reductions concentration with increasing application. However, this amelioration effect weakened time can significantly concentrations mineral reduce exchangeable Al. These effects are enhanced addition vary depending