微咸水非充分灌溉对土壤水盐分布与冬小麦产量的影响

Effects of deficit irrigation with brackish water on soil water-salt distribution and winter wheat yield

为了实现高效用水,缓解北方地区水资源紧缺的状况,根据河北省中科院南皮生态农业试验站2003-2005年的冬小麦微咸水非充分灌溉田间试验资料,研究了微咸水非充分灌溉对土壤含盐量、冬小麦产量和产量构成因素以及水分利用效率的影响。结果表明,从拔节前到麦收后的冬小麦主根区土壤含盐量随着生育期的发展呈明显升高趋势;随着缺水阶段的后移,0～100cm深度土壤积盐程度逐渐增大;穗粒数对缺拔节水敏感程度最高,缺抽穗水对单位面积穗数的影响最大,缺灌浆水对千粒重的负效应最大;总的来说产量随着缺水阶段的后移,水分胁迫的负效应逐渐减小,水分利用效率随着缺水阶段的后移有所提高,微咸水非充分灌溉的灌水优先顺序应为拔节水、抽穗水和灌浆水。该研究为黄淮海地区冬小麦在微咸水非充分灌溉下的适宜灌溉次数和灌溉水量的确定提供了科学依据,有利于合理开发利用当地微咸水资源。

For the sake of improving water utilization efficiency and relieving the shortage of water resource in North China,field experiments on deficit irrigation with brackish water were carried out at Nanpi Ecological Experimental Station of Chinese Academy of Science in Hebei province from 2003 to 2005,which aimed at exploring the impact on soil salt content,winter wheat yield and yield constitute factors as well as water use efficiency caused by brackish water irrigation.The results showed that, soil salt content in winter wheat main root area had an increasing trend with growth duration development, salt accumulation in O-100 cm soil layer increased gradually in company with water shortage stage postponement. Yield constitute factors most sensitive to water deficit in jointing period was the number grains per spike, water deficit in the tassel stage was the most influential factor to spikes per unit, water deficit in the grouting stage had critical negative effects to 1000-grain weight. In general, with water shortage stage postponement, negative effect of water stress on winter wheat yield gradually decreased, and water use efficiency increased, the preferred order of deficit irrigation with brackish water was jointing stage irrigation, tassel stage irrigation and grouting stage irrigation. The study provides the scientific basis for determining suitable irrigation frequency and the normal amount of irrigation in winter wheat growth stage under condition of deficit irrigation with the brackish water in Huanghuaihai Plain, which is favorable for the rational exploitation and utilization of local brackish water resources.