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41.
42.
在大同县罗庄村玉米地进行洪水灌溉与清水灌溉的大田灌水试验,研究在不同的灌水定额下,用洪水与清水灌溉后,土壤剖面上盐分的运移规律。研究结果表明:用洪水与清水灌溉后,土壤中盐分的运移规律基本相同;盐分随水分运动而向下运移的深度随灌水定额的增大而增大。 相似文献
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不同降雨年型下水分处理对大穗型小麦品种籽粒灌浆及产量的影响 总被引:33,自引:0,他引:33
在大田条件下,探讨了不同降水年型不同水分处理条件下大穗型小麦品种籽粒灌浆及产量的变化。结果表明:通过用不同方程对籽粒生长动态进行拟合,Cubic方程最精确。2000~2001干早年型W和Ws与两个灌浆持续期参数(Se、S)相关性显著.2001~2002丰雨年型W和Ws与3个灌浆速率参数(V、Vs、Vmax)间相关性达显著水平。两年度相比,2000~2001年度籽粒灌浆持续期短,灌浆速率小,导致粒重降低。灌水对灌浆参数的效应年际间存在差异,2000~2001年度随灌水次数增多,S和Se延长,灌浆速率降低;而2001~2002年度随灌水次数增多,S和Se缩短,灌浆速率以灌—水处理最小.灌两水处理最高。灌水对产量的影响,2000~2001年度显著增产,2001~2002年度处理间无显著差异,灌三水处理较灌两水处理反而减产。 相似文献
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Although ‘sewage farming’ or wastewater irrigation started in Australia in the latter parts of the 19th century, it was in the late 1960s that a considerable interest was revived in arid and semi-arid parts of the world due to scarcity of alternative water sources and the urgency to increase local food production. The practice has manifold benefits in the form of water conservation, nutrient recycling, surface and ground water pollution prevention. But for arid and semi-arid regions like many parts of Australia, while wastewater irrigation can be an attractive solution to irrigation water problems, it might not be the ideal solution for the common soil types encountered in these regions. Due to characteristic low rainfall, high evaporation and low leaching, these soils tend to have higher salt accumulations. This paper examines the soil salinity and sodicity effects of wastewater irrigation in soil types typical to South Eastern Australia and takes the soils of Western Treatment Plant (WTP) as a case study to highlight these issues. 相似文献
47.
Ian Moorhouse 《Irrigation and Drainage Systems》1999,13(2):165-187
This paper presents a case study of Goulburn-Murray Water's approach to the development and implementation of its asset management program for irrigation infrastructure. The success and effectiveness of asset management is not a matter of technical aspects only, rather it depends on an integrated package of institutional, organisational, technical and financial aspects. 相似文献
48.
Yield and growth characteristics for cotton under various irrigation regimes on sandy soil 总被引:1,自引:0,他引:1
W.R. DeTar 《Agricultural Water Management》2008,95(1):69-76
Over-watering cotton wastes a valuable and scarce resource; it can also lead to rank growth, nutrient leaching, and contaminated groundwater. Since under-watering can decrease yields, the question becomes one of finding the optimum application regime. An irrigation experiment was set up to apply water at six different application rates, ranging from 33% to 144% of normal, with hopes of identifying the regime that produces maximum yield. Two cultivars, Acala Maxxa and Acala PhytoGen-72 (Gossypium hirsutum L.), were planted on sandy soil and irrigated daily with a highly efficient subsurface drip irrigation system for four seasons. The results showed that on the average there was no significant difference in the yield of the two cultivars and there was no significant difference in the yield for the three wettest treatments. The driest of the three wettest treatments, treatment 4, was a critical point on the water production function curve. It represented the least amount of water applied that still produced essentially maximum yield, and it had the highest water use efficiency. This critical level of water application during mid-season was found to be, on the average, 95% of Class A pan evaporation; it corresponded to a total seasonal application of 654 mm of water. Any application less than this critical level decreased yields. Reducing the water application by 5% below the critical level caused about a 4.6% reduction in yield. The critical level produced a soil moisture level that remained nearly constant throughout the season. The final plant height was closely related to the depth of water applied, with the wettest treatment producing plant heights of 2.0 m, and the driest treatment producing plant heights of 0.6 m. At the extremes of the water application rates there were some small differences in the early-season growth rate of the plants, but the main cause of differences in final plant height was the date of cutout (cessation of main stem node production). The length of season for the driest treatment was about 4 weeks shorter than for the wettest treatment on both cultivars. Results showed that deficit irrigation of cotton on sandy soil can greatly reduce yield, and the practice should probably be avoided. 相似文献
49.
随着我国农业科技的发展,滴灌施肥智能化控制技术越来越引起人们的关注,成为未来优质高效设施农业的发展趋势。为此,通过市场调研,采用PLC控制技术,进行了自动化灌溉施肥系统的设计开发;通过性能测试,实验取得了较好的效果,为将PLC技术引入到灌溉施肥控制系统的后续研究提供了借鉴。 相似文献
50.
水分和氮素管理对提高作物产量具有重要作用。笔者研究尿素类型与灌溉管理对玉米节水保肥的影响以达到玉米高氮肥利用效率和高产田的生产目标。本研究在2016—2017年开展2年完全随机区组设计试验,讨论了尿素类型(普通尿素和控释尿素)及灌溉对玉米土壤和氮素利用的影响。每种尿素类型设置2种氮素水平,分别为75、150 kg N/hm2,以不施氮肥为对照。水分设置2种灌溉水平,分别为全生育期不灌水和灌浆阶段灌水85 mm。结果表明:在灌溉与施氮水平相同下,0~40 cm土层应用控释尿素处理氮含量较高,但在更深的土壤层低于普通尿素处理;相对于不灌溉,灌溉增加了硝态氮的损失,但施用控释尿素的处理硝态氮损失低于施用普通尿素处理;灌溉条件下施用控释尿素可以提高玉米氮素吸收,并使更多的氮向籽粒中转移;与普通尿素相比,控释尿素提高了氮肥利用率,降低土壤对氮需求的依赖。控释尿素低氮的释放可以减少硝态氮在土壤中的存留时间而迅速被玉米吸收,从而降低硝态氮的损失风险,提高了土壤氮肥利用效率。综上,控释尿素与少量灌溉相结合适用于华北半湿润地区达到玉米高氮肥利用效率和高产田的生产目标。 相似文献