干旱区杨树人工用材林灌溉量与土壤水分的关系

The Relationship between Different Amounts of Irrigation and Changes of Soil Water Content in Populus ×xiaozhuanica cv.‘popularis’Plantation in Arid Area in lnner Mongolia

对内蒙古干旱河套黄灌区，群众杨人工用材林灌溉量与土壤水分试验表明：（１）在１５００～７５００ｍ３／（ｈｍ２·ａ）供水量范围内，灌溉效果以７５００ｍ３／（ｈｍ２·ａ）灌溉量最佳。（２）１５００ｍ３／（ｈｍ２·ａ）灌溉量的有效浸润层为２０～５０ｃｍ；４５００ｍ３／（ｈｍ２·ａ）的有效水分层为５０～７０ｃｍ；７５００ｍ３／（ｈｍ２·ａ）为５０～１００ｃｍ；２２５００ｍ２／（ｈｍ２·ａ）为０～７０ｃｍ。（３）７５００ｍ３／（ｈｍ２·ａ）灌水量与１５００、４５００、２２５００ｍ３／（ｈｍ２·ａ）灌水量相比；在２０ｃｍ土层内最大吸湿量分别提高２．２５、０．４４、０．６７ｍ３；３０ｃｍ土层提高３．７１、１．１２、１．６３ｍ３；土壤含水量占田间持水量百分比分别提高２６．９％～２３．３％、５．７％～５．０％、１６．２％～７．１％；土壤总蓄水量分别提高３１０．４、４５６．６、１１９０．２ｍ３。（４）０～１００ｃｍ各土层的水分亏缺值（Ｋ）分别降低２３．３％～２６．８％、５．１％～５．８％、７．２％～１６．３％。（５）土壤盐分变化随灌溉量增大而加剧。

The Research on the relationship between different amounts of irrigation andchanges of soil water content in Populus ×xiaozhuanica cv. ‘popularis’was conducted inthe arid area,Inner Mongolia. The results showed that :(1)the best irrigation amount was7500 m3 /(hm2 ·a );(2)the effective absorbed moisture soil layer with an irrigation of 1 500m3/(hm2·a),was 20～25 cm deep ,while those with irrigation of 4 500,7 500 and 22 500m3/(hm2·a),were 50～70 cm, 50～100 cm, and 0～70 cm deep respectively;(3)in the soillayer of the former(0～20 cm deep),the maximum capacity of absorbed moisture was raisedby 2. 25,0.44,and 0. 67 m3 respectively as compared with those plots with irrigation amountof 1 500,4 500,and 22 500 m3/( hm2·a);while in the soil layer of 0～30 cm deep of theformer that was raised by 3.71,1.12,and 1.63 m3 as compared with those plots mentionedabove. The percentage of soil water content in field moisture capacity of the former ones wasraised by 26.9%～23.3%,5.7%～5.0%,and 16.2%～7.1 %respectively;The total soil water storage capacity of the former was raised by 310.4,456.6,and 1190.02 m3 respec-tively,The water shortage value(K)in the soil layer from 0～100 cm of the former was de-creased by 23. 3%～26.8%,5.1%～5.8%,and 7.2%～16.3%respectively;(4)finally themore the irrigation,the bigger the salt content.