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为优化紫花苜蓿人工草地的非充分灌溉方式,逐步提高水分利用效率。本实验采用田间观测法,遵照以水定草、最大调亏的逆向思维,参照紫花苜蓿SPAC水分运移规律,对灌溉定额3 600 mm3/hm2(近似于360 mm降水)和1 800 mm3/hm2(近似于180 mm降水)进行了比对试验。结果表明在日均高温大于23℃的高耗水阶段减少充分灌溉定额的50%水量,在理论上放弃第二茬紫花苜蓿的产量,以最低灌溉量维持其主根颈以下免于严重失水导致萎蔫,度过高温高耗水时期再将灌溉量的余额分配于第三茬,最终减产率为29.1%,节水率50%。
In order to optimize the non-sufficient irrigation methods of alfalfa artificial grassland and gradually increase the water use efficiency. In this experiment, the field observation method was used to observe the water transport law of alfalfa (SPAC) under the water flowering grass and the maximum loss-adjusted reverse thinking. The irrigation quota of 3 600 mm3 / hm2 (similar to 360 mm precipitation) and 1 800 mm3 / hm2 (Similar to 180 mm precipitation) for the comparison test. The results showed that reducing 50% of the full irrigation quota during the high water consumption period with the daily average high temperature above 23 ℃ could theoretically abandon the second crop of alfalfa and maintain the lowest irrigation below the main root neck to avoid serious water loss Wilting, over the period of high temperature and high water then the amount of irrigation allocated to the third crop, the final reduction rate of 29.1%, water-saving rate of 50%.