干旱半干旱地区砂田结构及水分特征  

Soil Profile Structure and Moisture Character of Gravel-Sand Mulched Field in Arid and Semiarid Area of China

作　　者：逄蕾[1,2,3] 肖洪浪[2] 路建龙[1] 周茂先[2] 谢忠奎[2] 李彩芝[2] 赵良菊[2] 柴守玺[1] 常磊[1] 任娟[2] 

机构地区：[1]甘肃农业大学农学院,甘肃兰州730070 [2]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000 [3]甘肃农业大学甘肃省干旱生境作物学重点实验室,甘肃兰州730070

出　　处：《中国沙漠》2012年第3期698-704,共7页Journal of Desert Research

基　　金：公益性行业(农业)科研专项(200903007-07);国家科技支撑计划项目(2012BAD14B10);国家公益性行业(农业)计划项目(201103001)资助

摘　　要：为研究砂田的剖面结构和水分特征,对可用砂田和废弃砂田的剖面结构、土壤含水量、容重和田间最大持水量进行分析测定;建立模拟砂田,研究不同的砾石覆盖条件对土壤水分的影响。结果表明,具有共性的砂田剖面分为5层,分别命名为覆盖层、混合层、根系密集层、淋溶层和钙积层。砾石覆盖可以显著增加土壤含水量,加深淋溶层的下限,剖面结构完整的砂田比结构不完整的砂田的土壤水分状况好。下层土壤含水量显著受上层土壤含水量的影响。以小粒径砾石覆盖且覆盖厚度9cm,最适土壤水分积累。砂田在覆砂的第一年土壤水分含量最低,之后逐渐增加,至覆砂后的6～12a,土壤水分含量达到最高,之后逐渐降低。覆砂后6a左右,土壤容重最小,田间持水量达最大值,此后随着砂田使用年限的增加,土壤容重逐渐增大,田间持水量逐渐减小。Soil profile, soil moisture content （SMC）, soil bulk density and soil water holding capacity both of in-using gravel-sand mulched field （GSMF） and abandoned GSMF in arid and semiarid area were determined to study soil profile structure and soil moisture characters of the GSMF. The effects of different gravel-sand mulching conditions on SMC were also studied through GSMF simulating experiment. The profile of GSMF has five layers, they are gravel-sand mixed layer, soil and gravel-sand mixed layer, roots dense layer, eluvi- ating layer and calcium accumulation layer, respectively. Gravel-sand mulching can increase SMC signifi- cantly, and makes the eluviating layer deeper. The soil moisture condition in the GSMF which has full soil profile is better than in the GSMF which hasn＇t full soil profile. The SMC in upper soil layer is influenced significantly by deeper soil layer. The thickness of 9 cm and the small diameter of gravel-sand can help SMC accumulation. The SMC was the lowest in the first year after gravel-sand mulching, and then it increased slowly with the mulching duration increased. During the mulching year from the sixth to twelfth, the SMC reached the highest level, and then it decreased slowly with the mulching duration increased. When the mulching time is at the sixth year, the soil bulk density reached the lowest, and the water holding capacity reached the highest level, then with the gravel-sand mulching duration increased, the soil bulk density in- creased and the water holding capacity decreased slowly.

关 键 词：砂田 剖面结构 土壤水分 容重 田间最大持水量 

分 类 号：S152.7[农业科学—土壤学]