中文摘要：

以科尔沁沙丘-草甸相间地区表层土壤为对象,选用4种不同测试方法,对不同地貌与植被类型组合区土壤的田间持水量进行综合测定,并对其影响因素和影响过程进行系统分析。结果表明：1在不同地貌类型区4种试验方法得到的田间持水量变化的规律大体一致,但数值差异很大。威尔科克斯法结果比围框淹灌法和天然降水法测定结果大。2草甸地受地下水位埋深的影响很大,围框淹灌法及天然降水法测定结果不可用;沙丘区地下水位埋深大,围框淹灌法与天然降水法获得的田间持水量对实践更具指导意义,天然降水法在地下水位深埋大的沙丘区表层40 cm以内基本可以获得较准确的田间持水量,取样时间可以在降雨后12~24 h。3科尔沁沙地实施田间持水量测量时建议选用天然降水法,对漫灌型农田土壤小面积也可选择围框淹灌法,大面积测量宜选择威尔科克斯法,但应建立威尔科克斯法与天然降水法和围框淹灌法之间的转换关系,利用威尔科克斯法测量田间持水量时,沙性土壤的测量时间可选择36~40 h、草甸区壤沙土与沙壤土可选择44~48 h。

英文摘要：

In order to make a reasonable irrigation regime,it is important to get the field capacity quickly and accurately,which can be used to determine the water capacity and drought index. In this study,the topsoil in the sand-meadow land in Horqin was regarded as the research subject,four test methods were used to measure the values of field capacity under the different combinations of landform and vegetation,and the affecting factors and process of field capacity were systematically analyzed. The results are as follows： 1 The variation pattern of field capacity obtained from the four different test methods under different combinations of landform and vegetation were generally consistent,but the values varied considerably. The results got from the water characteristic curve method based on the pressure plate and chose appropriate negative pressure were consistent with those from the Wilcox method. The box flooding irrigation method and natural precipitation method were both influenced by the depth of sampling,sampling time,landform,vegetation types,groundwater depth,and so on,especially the field capacity of meadow was affected by groundwater depth significantly,therefore the results were unavailable. Moreover,the field capacity obtained from the box flood irrigation method after rainfall was slightly higher,thus the test should not be conducted after rainfall; 2 The results measured by box flooding irrigation method and natural precipitation method in meadow area were unavailable because they were significantly affected by groundwater depth; the values of field capacity measured by box flooding irrigation method and natural precipitation method in the dune area where the groundwater depth was deep were of guiding significance,and the accurate values of field capacity of 40-cmdepth topsoil in the dune area where the groundwater depth was deep could be obtained by the natural precipitation method,and the measurement could be carried out after rainfall for 12- 24 hours; 3 It was recommended to measure the field capacit