Abstract:

It has become a general consensus that overapplication of common nitrogen fertilizer causes low crop benefit and soil environmental pollution. Regulating nitrification process is an effective way to ensure stable crop yield， reduce fertilizer dosage and soil nitrogen loss. On the basis of the same amount of phosphorus and potassium fertilizer， 6 nitrogen gradients were set： no nitrogen fertilizer （N0）， farmer fertilization （N130）， optimal fertilization （N100）， optimal reduction of common nitrogen fertilizer 20% （N80）， optimal reduction of slow release nitrogen fertilizer 25% （N₄₅75）， optimal reduction of slow release nitrogen fertilizer 40% （N₄₅60）.The effects of slow-release nitrogen fertilizer on winter wheat yield and soil nitrate/ammonium nitrogen content were analyzed under drip irrigation under the condition of reducing common nitrogen fertilizer. The results showed that the effective panicle number， kernel number per spike and 1 000-grain weight of winter wheat did not decrease significantly by applying slow release nitrogen fertilizer under the condition of reducing total nitrogen input， and the yield was still high. The agronomic efficiency of nitrogen fertilizer of N₄₅75 treatment was higher than that of other treatments， especially the increase of 44.57% compared with N130 treatment. The nitrogen partial productivity of optimal reduction treatment was higher than that of N130 treatment， and the nitrogen partial productivity of slow release nitrogen treatment was higher than that of common nitrogen treatment. The nitrogen partial productivity of N₄₅60 and N₄₅75 treatment was higher than that of N130 treatment by 79.08% and 63.32%， respectively. Nitrogen reduction treatment improved nitrogen use efficiency， and N₄₅75 treatment had the highest nitrogen use efficiency， which was 29.53% higher than that of N130 treatment. Reasonable application of slow release nitrogen fertilizer could reduce the content of nitrate/ammonium nitrogen in deep soil layer， thus reducing the risk of nitrogen leaching into deep soil layer. Therefore， the rational application of slow release nitrogen fertilizer could be an effective choice to stabilize the yield of winter wheat under drip irrigation and reduce environmental pollution. Above results provided theoretical support for the rational fertilization of winter wheat with drip irrigation， and had important significance for improving the production capacity of winter wheat and ensuring environmental safety.

Key words: slow release nitrogen fertilizer, winter wheat, yield, nitrate/ammonium nitrogen

摘要：

过量施用普通氮肥造成作物效益低及土壤环境污染已成为普遍共识，调控硝化过程是保障作物稳产、减少化肥用量及土壤氮素损失的有效途径。在磷、钾肥用量相同的基础上设置6个氮肥梯度：不施氮肥（N0）、农户施肥（N130）、优化施肥（N100）、优化减施普通氮肥20%（N80）、优化减施缓释氮肥25%（N₄₅75）、优化减施缓释氮肥40%（N₄₅60），分析在减少普通氮肥情况下施用缓释氮肥对滴灌冬小麦产量及土壤硝/铵态氮含量的影响。结果表明，在减少总氮投入的情况下施用缓释氮肥，冬小麦的有效穗数、穗粒数与千粒重未显著下降且产量仍较高，N₄₅75处理的氮肥农学效率高于其他处理，较N130处理提高44.57%。优化减施处理的氮素偏生产力均高于N130处理，并且施用缓释氮肥处理的氮素偏生产力均高于施用普通氮肥处理，其中N₄₅60和N₄₅75处理较N130处理分别提高79.08%和63.32%。减氮处理均提高了氮肥利用率，其中N₄₅75处理氮肥利用率最高，较N130处理提高29.53%。合理施用缓释氮肥会降低土壤深层硝/铵态氮的含量，从而减少氮素向土层深处淋溶的风险。因此，合理施用缓释氮肥可以作为一种既稳定滴灌冬小麦产量又减少环境污染的有效选择。以上研究结果为滴灌冬小麦合理施肥提供了理论支撑，对提升冬小麦生产能力、保障环境安全具有重要意义。

关键词: 缓释氮肥, 冬小麦, 产量, 硝/铵态氮