水氮互作对旱地春小麦氮肥利用效率和经济产量的影响

Effect of Interaction between Water and Nitrogen on Nitrogen Utilization Efficiency and Economic Yield of Spring Wheat in Dryland Region

为明确水氮互作对旱地春小麦氮素利用效率和经济产量的影响,通过盆栽试验分析了不同水氮处理下春小麦关键生育期茎秆、叶片、麦穗(不含籽粒)和籽粒的全氮含量及经济产量。结果表明,水氮互作下,春小麦茎秆、叶片和麦穗(不含籽粒)的全氮含量均随生长发育进程的推进而呈现下降趋势;正常水分条件(土壤含水量为最大持水量的75%～85%)下,春小麦茎秆、叶片、麦穗(不含籽粒)和籽粒的全氮含量均表现为中氮处理(每公斤土壤施纯氮0.15g)>高氮处理(每公斤土壤施纯氮0.25g)>空白对照(不施氮肥),且中氮处理的氮肥利用率、农学效率和生产效率均显著高于高氮处理(P<0.05),但经济产量却显著低于高氮处理(P<0.05);水分胁迫条件(土壤含水量为最大持水量的35%～45%)下,春小麦茎秆、叶片、麦穗(不含籽粒)和籽粒的全氮含量均表现为高氮处理>中氮处理>空白对照,但中氮处理的氮肥利用率、农学效率和生产效率及经济产量均显著高于高氮处理(P<0.05)。说明正常水分条件下,增加氮肥用量有利于提高旱地春小麦的经济产量,而水分胁迫条件下,减少氮肥用量更有利于旱地春小麦的生产。

In order to clarify the effects of interaction between water and nitrogen on nitrogen utiliza- tion efficiency and economic yield of spring wheat in dryland region, the total nitrogen content in stalks, leaves, ears without grains and grains of spring wheat during key growth periods as well as e conomic yield were studied by pot-culture method. The results showed that the total nitrogen con- tent in stalks, leaves and ears without grains of spring wheat was generally decreased with the growth process under the circumstance with interaction between water and nitrogen. Under normal soil mois- ture conditions, the total nitrogen content in stalks, leaves, ears without grains and grains ranked as medium nitrogen fertilizer〉high nitrogen fertilizer〉no nitrogen fertilizer. Nitrogen use efficiency and agronomic efficiency as well as production efficiency under medium nitrogen fertilizer were significant ly higher than those under high nitrogen fertilizer, but economic yield under medium nitrogen fertilizer was lower than that under high nitrogen fertilizer. Under water deficient conditions, total nitrogen content in stalks, leaves, ears without grains and grains ranked as high nitrogen fertilizer〉medium nitrogen fertilizer〉no nitrogen fertilizer, but nitrogen use efficiency, agronomic efficiency and pro- duction efficiency as well as economic yield under medium nitrogen fertilizer were significantly higher than those under high nitrogen fertilizer. It can be concluded that under normal water conditions, the increase of nitrogen application can improve the economic yield of spring wheat in dryland region; un-der water deficient conditions, the decrease of nitrogen application is beneficial to the production of spring wheat.