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[摘要]
通过测坑及田间试验,探究地下膜调控润灌条件下冬小麦各生育期的耗水量、耗水强度及模系数,研究不同 供水条件对作物产量和水分利用效率的影响,提出该灌水技术条件下所研究作物的适宜灌水定额和灌溉制度。 研究表明:在试验设定的灌水量范围内,较小的灌水定额可获得较高的水分利用效率;综合考虑产量和水分利用 效率,地下膜调控润灌条件下冬小麦较优的灌水处理为 SM处理,即灌水定额为 450?m 3/hm 2,灌水时期分别是返青、 拔节、抽穗、灌浆 4 个时期,灌水次数为 4 次,灌溉定额为 1?800?m 3/hm 2;在 SM处理下,冬小麦产量可达到 9?520.03 kg/hm 2,水分利用效率可达到 2.85?kg/m 3。该试验结果可为缺水地区冬小麦种植探究高效可行的灌溉方式提供合 理的参考依据。
[Key word]
[Abstract]
Underground film control irrigation is an irrigation technique that combines drip irrigation and film mulching technology by burying the drip irrigation pipe underground. The upper and lower layers of the control film are square impermeable polyethylene film, 25 cm x 40 cm, with a permeable substrate layer of filter cotton in the middle and the same size as the upper film. The drip head is designed for a flow rate of 2.0 L/h and a spacing of 80 cm. After the drip irrigation pipe is placed in the ground at 35 cm, the upper and lower films are placed at the top and bottom of the drip head respectively, and the symmetrical centres of the upper and lower films coincide with the drip head. The principle of underground film regulated wet irrigation is to use the water absorption force of soil water to make water and fertilizer stay and evenly distribute in the main root layer of the crop, which will help the root system to fully absorb and use water resources, thus reducing the loss of ineffective water and fertilizer, and play an important role in promoting the solution of the problem of water scarcity in agriculture in the North China Plain. This experiment was divided into a pit test and a field test. The pit test used 9 pits of 2 m×3.33 m, and the test factor was total irrigation control, with three treatments of total irrigation level: 4 500 m3 /hm2 (T1 ), 4 200 m3 /hm2 (T2) and 3 900 m3/hm2(T3 ). The plots were randomly arranged in nine test pits. The trial field was 44.2m wide from east to west and 64 m long from north to south, covering an area of about 4 acre. The three irrigation level treatments were 540 m3/hm2 (H), 450 m3/hm2 (M) and 360m3/hm2 (L), using an orthogonal test design with six treatments, each replicated three times, in a total of 18 plots, each 30 m long and 5 m wide, with a plot area of 150 m2 . The pit and field tests were conducted to investigate the water consumption, water intensity and modal coefficients of winter wheat at various stages of fertility under underground film-controlled wet irrigation, to investigate the effects of different water supply conditions on crop yield and water use efficiency, and finally to propose suitable irrigation quotas and irrigation systems for the crops studied under underground film-controlled wet irrigation technology. The results of the pit test showed that the water consumption and yield of winter wheat increased with the increase of irrigation water within a certain irrigation range, the crop yield was the highest in the high water treatment T1 , but the water use efficiency was the highest in the medium water treatment T2 . The analysis of variance showed that the treatment with the highest irrigation amount achieved the highest yield but did not reach a significant difference with the medium water treatment. In the field trials, the water use efficiency of SH , SM and SL with a lower irrigation limit of 55% field water holding capacity was generally higher than that of NH, NM and NL with a lower irrigation limit of 65% field water holding capacity. The NH treatment had the lowest water use efficiency of 2.33 kg/m3 and the SM treatment had the highest water use efficiency of 2.85 kg/m3 . This shows that the SM treatment was the better irrigation treatment under the experimental conditions. This is in line with the results of the pit test, which showed that a smaller irrigation rate can achieve higher water use efficiency. Under the SM treatment, the yield of winter wheat could reach 9 520.03 kg/hm2 and the water use efficiency could reach 2.85 kg/m3, which could provide a reasonable reference for exploring efficient and feasible irrigation methods for wheat cultivation in water-scarce areas.
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