Pesticide persistence in soil is affected by which two factors?

Pesticide persistence in soil is primarily influenced by the application rate and organic matter concentration. The application rate determines how much pesticide is introduced into the environment, and higher rates may result in longer persistence as there is more chemical residue present. On the other hand, the concentration of organic matter in the soil is critical because organic matter can bind to pesticides, affecting their breakdown and availability to microorganisms that typically degrade them. When pesticides are more tightly bound to organic matter, they are less likely to leach away or break down quickly, thereby increasing their persistence in the soil.

The factors related to temperature, humidity, soil pH, moisture levels, wind speed, and sunlight exposure also have roles in pesticide dynamics but are secondary in terms of persistence compared to the application rate and organic matter concentration. Each of these secondary factors can influence the degradation processes or mobility of pesticides in the environment but do not directly dictate their longevity in the soil to the same extent as the two key factors of application rate and organic matter concentration.