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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。
In order to study the profile structure and water characteristics of the sand field, the profile structure, soil moisture content, bulk density and the maximum water holding capacity of available sand field and abandoned sand field were analyzed and determined. The simulated sand field was established to study the influence of different gravel covering conditions on soil moisture. The results show that the common sandstone section is divided into five layers, named as cover layer, mixed layer, root dense layer, leaching layer and calcium layer. Gravel covering can significantly increase soil water content and deepen the lower limit of leaching layer. Sandy area with complete section structure is better than soil with incomplete structure. The lower soil moisture content is significantly affected by the upper soil moisture content. Cover with a small particle size of gravel and cover the thickness of 9cm, the optimum soil moisture accumulation. The content of soil moisture was the lowest in the first year of sand mulching and then gradually increased. From 6 to 12 days after the sand mulching, the soil moisture content reached the maximum and then gradually decreased. After covering the sand about 6a, the soil bulk density is the smallest, and the water holding capacity in the field reaches the maximum. Since then, as the service life of the sand field increases, the soil bulk density gradually increases and the water holding capacity in the field decreases gradually.