不同矿化度滴灌水对沙漠公路防护林土壤微生物的效应分析

在塔里木沙漠公路防护林区,选取四种滴灌用水矿化度值2.58/g.L-1、5.75/g.L-1、8.90/g.L-1和13.99/g.L-1的防护林地,采集0-5cm、5-15cm、15-30cm和30-50cm土层的土壤,分析了土壤微生物在不同矿化度滴灌水作用下的变异规律,结果表明:滴灌用水矿化度值不同的防护林地土壤微生物数量差异明显,微生物数量随矿化度值增大而减少;不同土层间土壤微生物数量亦出现差异,中层土壤最大;当滴灌用水矿化度值增大时,土壤盐分含量会升高;由于高矿化度滴灌水的作用,土壤物理结构变差,从而影响速效养分的积累。由此可见,高矿化度滴灌水会使土壤积盐、板结硬化,不利于土壤团粒结构形成和养分活化积累,土壤质量下降,从而抑制土壤微生物生长和发育。

Effects of Drip Irrigation Water with Different Salinity on Soil Microbes in Tarim Desert Highway Forest

Four types of forest were selected which was irrigated with the water with different mineralization degrees of 2.58/g L-1,5.75/g·L-1,8.90/g·L-1 and 13.99/g·L-1 in the region of Tarim desert highway forest belt,and soils were sampled from depths of 0-5cm,515cm,15-30cm and 30-50cm.The variation law of soil microbe under the different mineralization degree of irrigation water was studied.The main results showed: the differences of the quantities of soil microbe among the forests with different mineralization degrees of drip irrigation water were obvious,and with the increase of the mineralization degree of drip irrigation water,the soil microbe quantities decreased;furthermore,the quantities of soil microbes in the different soil depths were also different,the highest value appeared in middle soil depth;soil salty content increased as the mineralization degrees of drip irrigation water elevated;soil physical structure bad under higher mineralization degree of drip irrigation water,thus soil available nutrient content declined.So we can conclude that the irrigation water with higher salinity would damage soil aggregate structure and active nutrient formation owing to salt accumulation,consequently,soil quality declined and went against soil microbe growth and development.