土壤学报2016，Vol.53Issue(1)：103-116,14.DOI:10.11766/trxb201505130096
咸水滴灌下塔克拉玛干沙漠腹地人工防护林土壤水盐动态
Dynamics of Soil Water and Salt in Soil under Artiifcial Plantation Shelterbelt Drip-irrigated with Saline Water in the Center of the Taklimakan Desert
摘要
Abstract
Soil water,as the major component of water in desert ecosystems,is the most important environmental factor which limits the growth and productivity of the vegetation. Specifically,soil water plays a significant role in the development,evolution and productivity of sand soils,as well as in maintaining the structure stability and function of desert ecosystems. Besides,it can make a great difference on the windbreak and sand-fixation,etc. The Tarim Desert Highway,crossing the Taklimakan desert,is protected by the artificial plantation shelterbelts along the highway. Due to high evaporation demand and extremely low rainfall in this region,it is very difficult to maintain the water balance of the sandy soil along the plantation shelter, thus leading to failure in meeting the normal water demand of plants without irrigation. Consequently,how to meet the water demand of plants is the key problem to sustain the plantation shelterbelt. Currently,pumped saline groundwater has been utilized to supplement the soil water loss in the shelterbelt. However,the soil salinization,caused by the long-term saline water(especially the saline water of high salinity)irrigation, inevitably hampers the construction and maintenance of the plantation shelterbelt. Solution for this problem is highly dependent on the understanding of the soil water and salt dynamics. Based on these,it is very necessary to carry out the dynamics of the soil water and salt in this region,and so on. In order to reveal the laws of spatial and temporal dynamics of the soil water and salt in the soil under artificial shelterbelt drip-irrigated with saline water in the center of the Taklimakan Desert,a field study was carried out to monitor temporal variation and two-dimensional spatial distribution of soil water and salt in the soil between April and July during which four irrigation events occurred at the interval of 15 days. Results show that(1)in the soil under artificial shelterbelt drip-irrigated with saline water,dynamics of the soil water and salt displayed an obvious periodic rule,that is,within an irrigation cycle(15 days),soil water dropped rapidly in content during the first period from D1 to D4,slowed down in changing during the second period from D4 to D10 and leveled off during the third period from D10 to D15,and the variation as a whole fitted the law of diminishing power function(y=8.746t-0.270,t=1,2,3…),while soil salt was being leached out in the first 7 days and then accumulating in the following 8 days(7~15 d),and the variation as a whole fitted the equation of Parabolic Function(y=0.009t2-0.138t+2.269,t=1,2,3…);and(2)in the 0~60 cm soil layer,soil water displayed a monistic linear diminishing pattern in horizontal distribution,while soil salt,a monistic linear increasing pattern;and in the 0~120 cm soil profile,the distribution of soil water displayed a single-peak curve with the peak appearing at 20 cm in soil depth,while the distribution of soil salt fitted the inverse function model,and salt accumulated in the surface of soil(0~5 cm)forming a circle around the nozzle 45~60 cm in radius,where the salt content might reach as high as 10~20 g kg-1. Our results suggest that the dynamics of soil water and salt in the artificial plantation shelterbelts,affected by varying environmental factors such as irrigation,evaporation,air temperature,precipitation,vegetation,as well as the spatial variability of the soil properties,exhibit both generality and differentiation,regardless of spatio-temporal scales. Thus our study may provide theoretical basis for predicting dynamics of the soil water and salt, evaluating soil salinization and further optimizing the present irrigation regime for the artificial plantation shelterbelts in this region.关键词
咸水滴灌/水盐动态/人工防护林/塔克拉玛干沙漠Key words
Saline water drip-irrigation/Dynamics of water and salt/Artificial plantation shelterbelt/Taklimakan Desert分类
农业科技引用本文复制引用
丁新原,周智彬,徐新文,王永东,江源,鲁晶晶,常青..咸水滴灌下塔克拉玛干沙漠腹地人工防护林土壤水盐动态[J].土壤学报,2016,53(1):103-116,14.基金项目
水利部公益性行业科研专项(201401049)、中国科学院战略性先导科技专项(XDA05050504)、国家自然科学基金项目(41271341)共同资助 Supported by Ministry of Water Resources'Special Funds for Scientific Research on Public Causes (No. 201401049),Strategic Priority Research Program of the Chinese Academy of Sciences(No. XDA05050504),and the National Natural Science Foundation of China(No. 41271341) （201401049）
