小麦适宜地下水位试验

STUDY ON SUITABLE GROUNDWATER LEVELS FOR WHEAT GROWTH

本文主要研究小麦的适宜地下水位控制指标及土壤水分指标。水位指标采用动态和静态水位相结合的方法进行试验；耐渍、耐旱土壤水分指标应用土壤水分能量测试技术取得了能量指标。试验得出：小麦全生长期适宜地下水埋深指标为０．８ｍ，播种期如遇干旱抬高至０．５ｍ有利出苗齐苗，分蘖后至２月底逐渐降至０．８ｍ，小麦生长中后期３—５月间在雨后３—４天能由田面降落控制于０．８０ｍ；小麦生长中后期耐渍土壤水分指标为４０ｃｍ土层内的土壤水分吸力＞３ｋＰａ，耐旱土壤水分指标为４０ｃｍ土层内朵穗—抽穗开花期的吸力≤８０ｋＰａ，灌浆—成熟期吸力≤１００ｋＰａ。土壤通透性的通气孔隙指标为：耕层８—１５％，犁底层≥４％，淋溶层≥５％。昆山重壤土地区采用暗管排水，暗管埋深为１．０ｍ，间距１５ｍ可满足上述各项指标要求。

he suitable groundwater level and soil water indexes for wheat are mainly dis-cussed in this article,the groundwater level index was studied by the combined dy-namic and static water ievel method,while the energy indexes of both waterloggingand drought-enduring soil water were got using the technique of soil water energymeasurement.The suitable groundwater depth for wheat was 0.8 meter during thewhole grotVing season,if it's drought during planting,the depth shoued beraised to 0.5 meter for the full emergence of seedlings;during the period of af-ter tilling to the end of feberuary the depth should be cut down to 0.8 meter pro-gressively;and during the middle and later growing periods of wheat(March-May),the depth should be controled at 0.8 meter 3-4 days after rainfull.During the mi-delle and iater growing periods of wheat, the waterlogging enduring soii water in-dex was the lvater suction of>3kPa in the 40cm soil horizon,and the drought-enduring soil water index was the suction of≤100kPa in the 40cm soil horizon atbooting-heading and flowering stages.The aeration porosities for creating a goodaeration status of soils could be 8-15%in plowed layer≥4%in plow sole,and≥ 5% in B-horizon.In the heavy loam soil area of Kunshan, the pipe drainagewith a pipe depth of 1.0 meter and a distance of 15 meters could meet the needsof all indexes mentioned above.