无机与有机肥配施麦田(紫色土)铵态氮及硝态氮的时空变异

Temporal-spatial variations of ammonia and nitrate under application of inorganic and organic fertilizers in purple soil of winter wheat

试验研究无机与有机肥配施冬小麦紫色土NH4^＋-N及NO3^--N的时空变异特征结果表明，冬小麦不同生育期施肥后第15d和第120d紫色土NH4^-—N含量有两个显著的降低、升高转折点，第15d与N素的硝化作用和挥发作用有关，第120d受此阶段冬小麦的强烈吸收和肥料的矿化释放作用影响较大；土壤NH4^＋—N和NO3^--N含量在不同剖面（0～15cm、15～30cm、30～50cm土层）的分配明显受施用有机肥的影响，有机肥对NO3^-N有一定固持作用，阻碍了NO3^-—N向下迁移，各处理对NO3^-N迁移的固持作用表现为秸秆＋化肥〉猪粪＋化肥〉鸡粪＋化肥〉纯化肥处理；土壤NH4^＋-N与NO3^--N含量时空变异有较强的此消彼涨相关性，且施纯化肥处理最明显。

The temporal-spatial variations of ammonia and nitrate were studied under application of inorganic and organic fertilizers in purple soil of winter wheat, The results show that there are two obvious reduction and-increase turns for soil ammonia and nitrate during different growth periods of winter wheat, which are 15 days and 120 days after fertilizers application. The former （15th day） is believed to be related to nitrification and volatilization. The latter （120th day） is affected by both the strong absorption of plant and mineralization release. The trends of ammonia and nitrate in purple soil at different soil profiles （0- 15cm, 15-30cm, 30-50cm） are affected by organic manure, which means that the nitrate is retained to move slowly to some degree. The nitrate-retaining effect of each treatment behaves as straw ＋ fertilizer〉 pig manure＋ fertilizer〉 chicken manure ＋ fertilizer 〉pure fertilizer, There is significantly negative correlation between the quantity of ammonia and nitrate, and the pure fertilizer treatment is the most significant.