1.Organic matter decrease in soil
Without manure and straws returning, coupled with excessive use of chemical nitrogen fertilizer, the carbon content in soil exhausted, organic matter in soil decreased. It leads to the problem of soil acidification and salinization, which causes destroyed soil structure and low fertility.
2. The damaged soil structure
Due to the lack of organic fertilizer supplements in the soil, as well as unreasonable farming and irrigation, the surfeit use of chemical fertilizers has aggravated the destruction of the soil structure, resulting in more and more serious soil compaction, which directly affects the natural vitality and self-regulating ability of the soil.
3. Soil denudation
The main manifestation of soil denudation in cultivated land, water erosion, wind erosion and tillage erosion. There is excessive reclamation on hillside soil. For the hillside field especially with slope gradients steeper than 15%, soil erosion is serious. On the other hand, while the hillside soil was cultivated, it does not take any conservation tillage, such as sloping ladder, horizontal ditch farming, hedgerow protection, it surely aggravated the decreasing of fertility and water holding capacity.