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蒙城县位于淮北平原南部,涡河流域下游,面积2052平方公里,耕地192.3万亩,砂姜黑土159万亩,占耕地面积的82.7％,这类土壤的特点是:耕层浅,砂姜多,物理性能差,肥力瘠薄。地表30厘米以下,混杂有大量砂姜颗粒,深80～90匣米处,砂姜含量每立米为193公斤,占土体重量的12.4％,深180～190厘米处,为552.5公斤,占35.5％。土壤结构多为棱柱形,膨胀、收缩系数大,就是在高度熟化的0～15厘米的土层中,胀缩系数仍达22.5％。因此,旱时土壤龟裂,纵横裂缝随旱情的发展而扩大,形成旱灾。而雨后,则土壤迅速膨胀,
Mengcheng County is located in the south of Huaibei Plain, the lower reaches of the river basin, an area of 2052 square kilometers, 192.3 hectares of arable land, 159 hectares of shajiang black soil, accounting for 82.7% of the arable land, these kinds of soils are characterized by: shallow tillage, More, poor physical properties, fertility infertility. The surface below 30 cm, mixed with a large number of sand ginger particles, deep 80 to 90 box office, sand ginger content of 193 kg per meter, accounting for 12.4% of soil weight, deep 180 ~ 190 cm, 552.5 kg, accounting for 35.5 %. The soil structure is mostly prismatic, expansion, shrinkage coefficient is in the highly matured 0 ~ 15 cm soil layer, the expansion coefficient still reached 22.5%. Therefore, when the dry soil cracks, cracks and cracks along with the development of the drought to expand, the formation of drought. The rain, the soil rapidly expanded,