Herbicide is a kind of pesticide commonly used by farmers. It is mainly used to remove weeds in the field. Some herbicides remain in the soil for more than one year, which makes the sensitive crops suffer from different degrees of pesticide damage. For example, the herbicides mainly composed of Metsulfuron methyl, Chlorsulfuron methyl and amisulfuron methyl used in various places can easily cause yellowing, Dwarfing and other symptoms in the growth period of the following rice, which must be paid attention to and avoided as far as possible.

1、 Different herbicides should be selected according to different soil characteristics, microbial species, climate and irrigation conditions: herbicides containing Chlorsulfuron methyl are mainly degraded by hydrolysis in soil. When the field is alkaline soil, the amount of rainfall in the year of medication is low, and the soil is dry, their residual period in the soil is often prolonged, and the subsequent crops are vulnerable; on the contrary, the residual period of acid soil, wet soil or irrigated farmland is shortened, and the subsequent crops are relatively safe.

2、 Before planting the next crop, it is necessary to know whether the herbicides applied in the previous crop are harmful to the following crops: if the herbicides containing Chlorsulfuron methyl and Metsulfuron methyl were applied in the previous crop, such as maicaoping, maicaolin, etc., the next crop can not be planted with corn, soybean, cotton, peanut and other crops, and can not be used as seedling field. In recent years, the use of tribenuron methyl (also known as giant star, broadleaf Jing) in some places has caused different degrees of pesticide damage to the next peanut, resulting in difficult emergence, slow growth and low yield of peanut.

3、 To improve the application method and reduce the soil residual amount: first, the dosage should be accurate, the spraying should be uniform, and there should be no leakage or re spraying. If the herbicide containing Chlorsulfuron methyl was applied year after year, it would not only cause harm to the following crops, but also to the crops in the current season. Second, the use period should be flexible. It can be treated before and after planting, and can also be sprayed after sprout. At present, PST, Guang Ling Ling and atrazine should be sprayed early after seedling so as to reduce the dosage and reduce residues. When used after emergence, adjuvants or synergists should be added to improve the efficacy and reduce the dosage. Third, rational application of pesticides. When Chlorsulfuron methyl was mixed with 2,4-D butyl ester, the dosage of Chlorsulfuron methyl could be reduced by 50%. It can reduce the dosage by more than 30%.