不同补灌次数对旱地高产小麦氮素运转及产量的影响
Effect of supplemental irrigation on nitrogen translation and high-yield wheat yield in drylands
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摘要: 试验研究了不同补灌处理对旱地高产田小麦氮素运转和产量的影响。结果表明: 增加补灌次数和灌水量, 导致小麦籽粒蛋白质含量降低, 旱地CK处理籽粒蛋白质含量最高, 其成熟期积累量虽然比灌1水和2水的处理低, 但显著高于灌3水以上处理。适量补灌, 可提高籽粒产量, 提高氮素利用率。补灌次数和补灌量过多, 小麦贪青晚熟, 氮素转移量小, 氮素转移率亦大幅度降低, 对产量提高的贡献并不大, 且产量和产量构成因素中千粒重、穗粒数反而下降, 低于灌2水和3水处理。综合考虑产量和水分利用效率、蛋白质积累等因素, 在本旱地高产试验田, 拔节期、灌浆期2水补灌120 mm的W2处理是最经济高效的补灌方案。Abstract: The effects of different supplemental irrigation schemes on nitrogen translation and high-yield wheat yield in the drylands of Qingdao were investigated via field experiments. The results reveal that increasing supplemental irrigation negatively influences grain protein content, while grain protein content is highest under CK (dry land treatment). Grain protein accumulation under CK is lower than those under treatments with only one or two irrigations, however, obviously higher than those with four or five irrigations. Appropriate supplemental irrigation enhances grain yield and nitrogen utilization efficiency, while nitrogen transfer rates and amounts reduce under excessive irrigation. There is an insignificant yield difference between W4 (a three-time irrigation treatment at wintering, jointing and filling stages) and W3 (a two-time irrigation treatment at jointing and filling stages). With increasing frequency and volume of irrigation, wheat yield, 1000-grain weight and per-spike grain decrease accordingly. Based on yield, water use efficiency and grain protein accumulation under W2 at 120 mm irrigation at jointing and filling stages are optimum.