不同秋眠级数苜蓿品种吸水规律研究

以地下根系生长、地上生物量和土壤含水量之间的关系为对象,研究了8个不同秋眠级数苜蓿品种的吸水规律。结果表明:休眠和半休眠苜蓿品种的时空变化特征表现出一致性;随着生长年限的增加,土壤含水量呈递减趋势;年刈割3茬,地上生物量与苜蓿耗水量密切相关,呈“V”字型分布;生育期内,分枝期历时最长、耗水最多,开花期耗水速率最快;3年内,苜蓿根系主要分布在60 cm土层,侧根主要发生于0~40 cm层,60 cm层下无侧根发生。根系主要依靠侧根在120 cm土层内吸收土壤水分。

Regulation on Water Uptake of Different Fall Dormancy Alfalfa Cultivars

In order to find the regulation on water uptake of 8 different FD alfalfa cultivars,we studied on the relationship of root system,up ground biomass and soil moisture.The results showed that dormancy and semi-dormancy cultivars had the same characteristics in space-time.Water moisture had the decreasing trend with years going.When harvested three times one year,up ground biomass was closely related with water consumption.Both of them were distributing "V".During the bearing time,the most water consumption and the longest growing time were in branching stage,and flowering stage had the fastest water consumption speed.In three years,local roots of alfalfa mainly developed in the top 60 cm of soil and the secondary roots 40 cm while there were no secondary roots bellowing 60 cm of soil.Water uptake of root system of alfalfa mainly occurred from top layer to 120 cm layer of soil.