不同水肥调控对冬小麦群体动态及产量的影响

为探索渭北旱塬冬小麦高产高效栽培措施，通过大田试验研究渭北旱塬干旱气候条件下优化水氮管理、有机无机肥结合和秸秆覆盖对冬小麦群体数量与产量的影响。结果表明，各处理冬小麦群体数量从出苗期不断增加，到返青期达最大后开始下降。返青期以前，各处理群体数量没有显著差异，且以返青期漫灌的农户传统耕作处理最高；返青期后经拔节期追氮补灌，小麦群体数量和干物质量出现显著性差异，最终以增加秸秆覆盖和有机肥的优化水氮处理OM3最高。从经济效益上看，小麦籽粒产量和利润以有效穗数最多的OM3处理最高，分别为4500 kg/hm2和4534元/hm2，产量较传统耕作方式和对照分别提高了33.4%、127.8%，利润分别提高了22.7%、322.2%。因此，在渭北旱塬有限灌溉条件下，优化水氮管理不仅节约大量水资源，而且显著提高了小麦产量和农民的收益，具有很大的推广潜力。

Effects of Various Water and Fertilizer Controlling Measures on the Yield and Population Dynamics of Winter Wheat

A field experiment was carried out to study the effect of optimized nitrogen with supplementary irrigation, straw mulch, combination of organic manure and inorganic fertilizer on the population dynamics and yield of winter wheat. And it was to provide theoretical basis for the cultivation measures of grains yield and resource using efficiency in winter wheat of arid and semiarid areas. The results showed that the population amount of the each treatment were all increased after emergence, reached the highest at revival stage, and decreased afterwards. Before the revival stage, dry biomass was the highest in the conventional farming treatment, while there was no significant difference among all the treatments on the population amount. After the revival stage, significant differences were showed in the population amount and dry biomass; dry biomass was highest in the optimized mode 3 because of topdressing nitrogen and supplementary irrigation in jointing stage. Nitrogen and irrigation could improve the population and dry biomass. The economic benefit showed that the maximum yield was 4500 kg/hm2 in the optimize modes 3 which was 33.4%, 127.8% higher than the conventional farming and control treatment, respectively. The maximum profit was 4537 yuan/hm2 in the optimize modes 3 which was 22.7%, 322.2% higher than farmer mode and control treatment, respectively. In short, under the limited irrigation condition of Weibei dryland, optimized mode 3 could effectively save great amount of water resource , increase the grain yield and profit of winter wheat, so it has a great promotion value.