半干旱区全膜玉米集雨补灌水分利用效率研究

Efficiency of Water Application of Maize Rainwater Zrrigation in Semi-arid Corn Area

会宁县属陇中半干旱黄土丘陵区,水资源严重缺乏,6月下旬至7月上旬正值玉米需水关键期的短期干旱,是玉米生产的主要不利气候因素,集雨补灌是应对短期干旱,保证玉米稳产高产的必要条件。玉米拔节与大喇叭口2个关键期补水与补水量试验表明:集雨补灌后较对照增产1791.36～4086.33kg/hm2,增产率34.3%～78.3%;补水时期以大喇叭口期最佳,产量可达8201.44～9316.55kg/hm2,较拔节期同水量增产19.6%～22.7%;增产率、水分生产效率随着补水量的增加而增加,补水生产效率随着补水量的增加而降低,补水量以225m3/hm2为好,大喇叭口期补水225m3/hm2较补灌112.5m3/hm2增产率提高21.4个百分点、水分生产效率提高0.31kg/m3、补水生产效率下降8.27kg/m3。

Huining county is a semiarid hilly area,a serious shortage of water resources. The last ten-day of June to the first ten-day of July is critical period of maize water requirement of short -term drought,which is the major adverse climate of maize produstion.Rainwater harvesting for supplemental irrigation is response to short-term drought conditions and necessary to ensure high and stable yield of maize. Jointing and the big bell maize water supply tests showed that rainwater harvesting for supplemental irrigation had produced 1 791.36~4 086.33 kg/hm2,production rate was increased 34.3%~78.3%. The greatest replenishment period was the big bell. The yield was 8 201.44~9 316.55 kg/hm2,it was higher than the jointing stage with 16.9% ~12.4% . Yield rate and water use efficiency increased with the added water increasing. Water supplement production efficiency increased with the decrease of water.The water complementarity of 225 m3/hm2 was enough. The production of the big bell of supplementary irrigation water supplement 225 m3/hm2 was higher than 112.5 m3/hm2 with 21.4 percentage point,with the water use efficiency increased 0.31 kg/m3,while replenishment productivity fell 8.27 kg/m3.