1. Continuous cropping: It is the main artificial factor for the formation of diseased soil. The main reason is that due to the continuous cultivation of a class of crops, certain pathogens can be propagated year after year, accumulate in the soil, form diseased soil, and develop on an annual basis. For example, continuous cropping of solanaceous vegetables causes serious diseases such as epidemic diseases and blight. If the strawberry is used for more than 2 years, dead plants will be 30%-50%. 2, improper fertilization: a large number of application of chemical fertilizers, especially nitrogen fertilizer can stimulate the growth of soil-borne pathogens Fusarium, Verticillium and Rhizoctonia, thereby accelerating the occurrence of soil-borne diseases. Since the outbreak of cotton verticillium wilt in China in 1993, it has occurred almost consecutive years. It has been associated with the large amount of chemical fertilizers used in cotton fields and a large reduction in the amount of organic matter in the soil. 3. Nematode infestation: Soil nematodes are closely related to diseases. Soil nematodes can cause wounds in the roots of plants, and the disease can be aggravated by infection with pathogens. Nematodes and fungal diseases can occur at the same time. For example, cotton wilt and soil nematodes are inseparable. Cotton wilt in the United States is known as a wilt-nematode compound disease. Disclaimer: Some articles in this website have been transferred from the Internet. If you are involved in third party legal rights, please inform this website. phone Mask-Peel Off Mask,Face Mask,Approved Mask,Approved Facemask Guangzhou Lingxue Cosmetics Co., Ltd , https://www.lxgj188.com