Why should soft water rather than hard water be used to dilute pesticides

(Agricultural Wealth Network)    In the prevention and control of pests and diseases, because some farmers are not careful about the water they use to dilute pesticides, the pesticides cannot exert their proper control effect, which leads to control failure and even phytotoxicity, causing losses to agricultural production. As is well known, water is divided into hard water and soft water. So-called hard water refers to water such as well water, salt water, seawater and so on that contains more calcium, magnesium and other substances, with hardness generally at 18-20 degrees. If such water is used to dilute pesticides, the calcium, magnesium and other substances contained in the water can reduce the suspension rate of wettable powders or combine with the emulsifiers in emulsifiable concentrates to form calcium and magnesium precipitates, destroying the emulsifying performance of the emulsifiable concentrate. This will not only reduce the control effect of the pesticide, but also cause phytotoxicity. Soft water, such as river water, lake water and other fresh water, contains fewer calcium, magnesium and other substances, with hardness of about 7.5 degrees. It will not destroy the performance of the pesticide or reduce the control effect.