What is the most important factor for microbe action on herbicides?

Temperature and moisture are indeed critical factors influencing the activity of microbes on herbicides. Microbial activity in the soil is highly dependent on these two factors because they affect the metabolic processes of the microbes responsible for the breakdown of herbicides.

Temperature plays a vital role in enzyme activity and overall microbial growth rates. Higher temperatures generally increase microbial activity until a certain threshold is reached, beyond which microbial activity can decline due to stress conditions. Meanwhile, moisture is necessary for microbial survival and function; it facilitates nutrient transport and the biochemical reactions that help in the degradation of substances such as herbicides. Inadequate moisture can lead to a decline in microbial populations and slowing down of herbicide decomposition.

While organic matter contributes to enhancing microbial populations and pH can affect microbial activity by influencing nutrient availability and toxic compounds, they are not as directly impactful or critical to immediate microbial action on herbicides as temperature and moisture. Thus, understanding the relationship between these environmental conditions and microbial actions helps in managing herbicide application and ensuring effective degradation in agricultural practices.