不同施肥制度对土壤固定态铵含量的影响

Effect of different fertilization regimes on content of fixed ammonium in soil

依托长期定位试验(包括6个施肥处理:CK,不施肥;M,施循环猪圈肥;NP,施N、P化肥;NPK,施N、P、K化肥;NPK+M,N、P、K化肥+循环猪圈肥;PK,施P、K化肥),研究了不同施肥制度对下辽河平原地区潮棕壤固定态铵含量的影响及其变化过程。结果表明:随着种植时间推移,不同施肥模式下固定态铵含量均呈先降低而后逐渐稳定的趋势。与试验初期固定态铵含量相比,试验进行22年后,不同施肥处理固定态铵有18.0%~38.7%的释放。施用氮肥会导致土壤固定态铵含量降低;钾肥则能阻碍固定态铵释放,延缓其降低过程;单纯施用循环猪圈肥对固定态铵含量无显著影响;而施用N、P、K化肥基础上配施循环猪圈肥不仅可提高作物产量,且可使土壤固定态铵库保持在较高水平,有利于构建土壤氮素养分库,应为本地区旱田农业生产中的最佳施肥模式。

The aim of this study was to investigate the effect of different fertilization regimes on contents and dynamics of soil fixed ammonium in the low reach of Liaohe River plain based on a long-term in-situ experiment （ 22 years） , including six treatments, i.e. CK （ unfertilized con- trol）, M （recycled pig manure）, NP （mineral fertilizer NP）, NPK （mineral fertilizer NPK）, NPK＋M （recycled pig manure with mineral fertilizer NPK）, and PK （mineral fertilizer PK）. The results showed that the contents of soil fixed ammonium in the different fertilization treatments all decreased and then leveled off. Compared to the initial value, the release of soil fixed ammo- nium ranged from 18.0% to 38.7% in the different treatments. Application of nitrogen fertilizer would reduce the content of soil fixed ammonium, while potassium could retard the release of fixed ammonium. Recycled pig manure applied alone had no significant effect on the content of fixed ammonium, whereas combined application of recycled pig manure and NPK could increase crop yield, as well as maintain a high level of fixed ammonium, helping to build a great soil ni- trogen pool. Therefore, it can be s^ggested that application of recycled manure coupled with N, P and K fertilizers is an optimum fertilization regime in this region.