滴灌棉田根区水分对棉花干物质生产及水分利用效率的影响

【目的】研究滴灌条件下根区水分对棉花干物质生产、分配及水分利用效率的影响,为制定滴灌棉花水分精确管理制度提供依据。【方法】选用对水分敏感性不同的棉花品种为试材,分别设置常规滴灌和充分滴灌处理,在灌水前后监测土壤水分变化,同时测定棉花根系生长与分布、株高、叶面积指数及生物量等生理指标。【结果】常规滴灌量条件下土壤水分活动层集中在0～60 cm的土层中,且滴水前耕层土壤相对含水率均低于55%、滴水后可保持70%～80%的水分状况,有利于诱导根系纵向生长,维持生育后期较高的叶面积指数,并促进光合产物向产量器官蕾铃分配,从而提高了经济产量水分利用效率。不同品种对根区水分的反应差异较大,新陆早6号常规滴灌条件下皮棉产量低于新陆早8号,经济产量水分利用效率与新陆早8号无明显差异;充分滴灌条件下总生物学产量水分利用效率高于新陆早8号,经济产量水分利用效率显著低于新陆早8号。【结论】滴水总量在4 050～4 275 m3/hm2,依据品种对水分响应的差异,通过协调相关栽培技术,调控干物质生产及其在器官中的分配,可实现滴灌棉花产量与水分利用效率协同提高。

Effect of Water Around Root Zone on Dry Matter Production and Water Use Efficiency of Cotton Under drip Irrigation

【Objective】The aim of this text was mainly to study the influence of water around root zone on dry matter production and distribution,and water use efficiency of cotton and to give the base for making the accurate management regulation of field water under drip irrigation.【Method】The cultivars with different water-sensitivity Xinluzao 6 and Xinluzao 8 were selected as the experimental materials.Cotton roots and root-shoot ratio were studied with conventional drip irrigation and sufficient drip irrigation method,and at the same time,the indexes of the growth and distribution of cotton roots,plant height,leaf area and indexes of phisiological parameters of biomass were deterinined.【Result】The results show that the soil water activity layer of cotton in conventional drip irrigation chiefly concentrated on the layer of 0-60 cm and before drip irrigation soil relative water content in layer of 0-40 cm soil was lower than 55%,after drip irrigation soil relative water content can be kept by 70%-80% which promoted the root longitudinally grow and distribution proportion of photosynthetic products to bolls,economic yield water use efficiency was increased.The differences of response to water around root zone among varieties were great,lint yield of Xinluzao 6 was lower than that of Xinluzao 8 under conventional drip irrigation,however,there were no significant differences between economic yield water efficient of Xinluzao 8 and Xinluzao 6.Xinluzao 6 total biological yield water use efficiency was higher than that of Xinluzao 8,but economic yield water use efficiency was significantly lower than that of Xinluzao8.【Conclusion】These results suggest that both yield of cotton with drip irrigation and water use efficiency could be increased when total irrigation was controlled in 4 050～4 275 m3/hm2,dry matter production and their distribution in organs were well controlled based on the related culture technies.