农田秸秆覆盖条件下冬小麦增产的水氮条件

通过田间试验建立了冬小麦产量与灌水量及施氮量的关系模型,并作了模拟分析,以期研究旱地农田秸秆覆盖条件下冬小麦增产的水氮条件.结果表明:秸秆覆盖的冬小麦能否增产与水肥供应关系密切.生育期间没有补充灌水时,覆盖增产主要取决于氮肥用量,氮肥投入较少时覆盖冬小麦经济产量能取得显著的增产效果;氮肥用量较高时产量低于未覆盖处理.因此,在雨养农业区,通过配合适量的氮肥完全能够做到秸秆覆盖下增产增收.在不同氮肥用量前提下,覆盖的增产效果除了与生育期总灌水量有关外,还与灌水量在各生育期间的分配有关.因此,在有灌溉条件的地区,根据氮肥投入情况,将有限的水分配在作物最需要的时期才能取得秸秆覆盖下的节水高产.

Requirements of water and nitrogenous fertilizer to increase winter wheat yield under straw mulch

The field experiment was conducted to investigate the requirements of irrigation and nitrogen fertilizer to increase wheat yield under straw mulch after the models of yield were created. The results showed that the increase of yield depended greatly on N fertilizer and irrigation water when straw mulch was applied. If no irrigation water was supplied, the increase of yield in straw-mulch treatment depended on the amount of N fertilizer. The yield of straw-mulch treatment was much higher than that of no-mulch treatment when 240 kg/hm^2 N fertilizer was applied. The reverse was true when too much N fertilizer was applied. Higher wheat yield under straw mulch could be reached in rainfed areas based on appropriate N fertilizer. The increase of yield depended on the distribution of irrigation water at the different stages of wheat growth as well as the total amount of irrigation water when amount of N fertilizer was a constant. A water-saving way to obtain higher yield is to distribute the limited irrigation water to the key stage of wheat growth based on the N fertilizer when irrigation is available.