土囊分辨（To distinguish between soil sac）.doc

土囊分辨（To distinguish between soil sac） The questioner adopted acid soil mainly in the southern region, including: brown soil, brown earth, loess, gray brown earth, filling soil and so on. The basic soil is divided into the northern region, such as alkaline earth, yellow soil, black soil, brown earth, chestnut soil, etc. The main soil types: 1. The brown soil, brown soil and brown forest soil, mainly distributed in semi-humid and semi-arid region of mountain in the perpendicular band spectrum, such as the north slope of qinling mountains, lu-liang mountains, zhongtiao mountains, LiuPanShan during Chinas mountain and river basin of alum coniferous forest or needle mixed forests. Above the brown earth distribution. It has a well-developed profile of 1.5-2m, with litter, humus accumulation layer, viscose transition layer and loose maternal layer. The surface layer is about 15-20cm thick and the texture is mostly medium soil. Below is argillic firm heart soil, clay aggregation, thick about 30 to 40, rich in colloidal substance and clay, is an obvious nuclear shape or edge block structure, on the surface structure has obvious iron manganese by film. Then gradually transition to a lightly sticky substrate. K, Ca, Mg and Mn have significant accumulation in surface humus. Soil colloidal absorption is strong, soil substitution is about 5 to 25 equivalent / 100g soil, soil absorptive complex is mostly salt base saturation, salt base saturation is above 80%. The soil is slightly acidic, with a PH of around 6.5. The brown soil developed in the base of acid bedrock, with a PH value of 5.5 to 6, and the base saturation of salt is also low, about 60-70%. Brown loam nutrient release quickly, due to the heavy soil, structure and poor permeability, moisture infiltration not easily, in the high slope, vulnerable to drought threatened, in low-lying areas, and easy to form the waterlogging. 2. Brown soil, brown soil distribution area for the warm temperate semi-arid sub-humid mountain and