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一、黑土的形成条件 高密县位于胶东半岛的西部,胶莱河谷的南部,境内南部为低山丘陵区,中部及北部为低洼平原,北以胶莱河为界,东有胶河及墨水河,西有五龙河,河网密布,全县处于山河环抱之中。年雨量为700毫米左右,集中于七、八、九三个月,占年雨量的2/3。地下水位在1～4米左右。雨季南部丘陵区山洪下泄不畅,自古即在境内常泛滥成灾,并形成许多季节性积水洼地,这是为黑土形成的主要条件。 黑土为本县低洼地区的土壤,表土呈黑色,故农民称为黑土,主要分布于胶莱河,五龙河,柳沟河,胶河,墨水河等河流两侧的“河套”洼地内,约占全县耕地面积的一半,为本县的重要粮棉地。
First, the formation of black soil Gaomi County is located in the western Jiaodong Peninsula, south of the Jiaolai Valley, southern territory of the hilly area, the central and northern low-lying plain, north of the Jiaolai River as the boundary, east of the plastic river and ink River , West Wulong River, river network, the county is surrounded by mountains and rivers. Annual rainfall of about 700 mm, concentrated in seven, eight, nine three months, accounting for 2/3 of the annual rainfall. Groundwater level in the 1 to 4 meters. During the rainy season, mountain torrents in the southern hilly area were not well released. Since ancient times, floods and floodplains have often flooded the territory and many seasonal hydrophyla depressions formed. This is the main condition for the formation of black soil. The black soil is the soil in the low-lying area of this county. The surface soil is black. Therefore, the peasants are called black soil. They are mainly distributed in the “Hetao” depression on both sides of rivers such as the Jiaolai River, Wulong River, Liugou River, Accounting for about half of the county’s arable land, the county’s major grain cotton.