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我省冬季严寒少雪,早春冷暖骤变,寒旱交加,冬小麦每年的冻害死苗,已成为小麦生产上的主要灾害。浇冻水是防御冻害最有效的措施之一。小麦专家认为冻水是“必浇之水”。浇冻水,首先是改善土壤的物理状况,缓解土壤、特别是分蘖节处的温度变化。据测试,浇冻水麦田分蘖节处土壤温度比不浇的高1—1.5℃。其次是增加土壤含水量,我省冬季干旱少雪,蒸发量大,越冬期间土壤含水率下降2—6%。实践证明,如果土壤含水量仅满足小麦越冬始期的安全指标(沙壤16%、壤土、18%、粘壤20%),翌年小麦返青后,就不能满足小麦对水的需要。又由于温度低,欲浇不能,死苗就会大量发生。第三是缓和了小麦与春作物的需水矛盾。我省生产条件较差,春作物主要是棉花播种与浇小麦返青水矛盾愈来愈突出。如果小麦浇了冻水,则可冬水春用,推迟返青水,从而缓解这一矛盾。
Cold and snow in winter in our province less snow, sudden warming and cold in early spring, cold and drought, cold winter annual frost damage dead seedlings, wheat production has become the major disaster. Chilled water is one of the most effective measures to prevent frost damage. Wheat experts think frozen water is “must pour water.” Cold water pouring, the first is to improve the physical condition of the soil to ease the soil, especially the tiller node temperature changes. According to the test, pouring frozen wheat field tillering section of the soil temperature higher than the non-irrigated 1-1.5 ℃. The second is to increase the soil moisture content. The winter drought and snow-less in our province, the evaporation is large, the soil moisture content decreased by 2-6% during the winter. Practice has proved that if the soil moisture content only meets the safety index of winter overwintering (16% of sandy soil, 18% of loam soil and 20% of viscous soil), wheat will not be able to meet the water requirement after it returns to green in the following year. And because of low temperature, want to pour can not, dead seedlings will occur in large quantities. The third is to ease the contradiction between water demand of wheat and spring crops. Production conditions in our province is poor, the main spring crop cotton planting and turning green water contradictions more and more prominent. If wheat is poured with cold water, it can be used in winter and spring, delaying the rehydration of water, so as to alleviate this contradiction.