How long does paraquat lose its toxicity in soil

The volatilisation time of paraquat's toxicity in soil is usually one week, but the residue in soil may take years to be completely removed. Paraquat is a highly toxic pesticide and the time for its toxicity to disappear depends on a number of factors, such as the nature of the soil and environmental conditions. Paraquat contains mainly a polyamine salt, which can only exist stably in an acidic environment, while the soil is alkaline, and paraquat will rapidly passivate and lose its toxicity upon contact with the soil. According to the instructions for paraquat, the residual period is 7-10 days, i.e. most of the toxicity of paraquat will volatilise and disappear in 7-10 days after it has been used and air-dried, but the little toxicity that remains may take a longer time to disappear completely.

How long does it take for glyphosate to lose its toxicity in the soil*?
Glyphosate has a relatively short residual time in the soil and can even be used to plant crops the same day. Glyphosate binds quickly to metallic substances such as iron and aluminium in the soil after contact and thus becomes inactive, with less impact on the soil and the next crop. However, to be on the safe side, farmers are advised to wait three to seven days after a glyphosate shot before starting a crop.

Comparison of the time for different types of herbicides to lose their toxicity in the soil*
Different types of herbicides have different dissipation half-lives and persistence periods in soil. For example, the dissipation half-life of Haloxyfop-methyl in soil is about 20 hours, whereas the dissipation half-life of Quizalofop in soil is within one day. Some herbicides, such as ethoxyfluorfen, are slow to dissipate in soil, with dissipation half-lives of up to 30 days. Therefore, when selecting herbicides, it is necessary to take into account their dissipation rate and persistence period to avoid adverse effects on crops and the environment.

Influence of soil type on the time of disappearance of herbicide toxicity*
Soil type has an effect on the disappearance time of herbicide toxicity. Different soil types have different rates of herbicide disappearance and holding periods. For example, under the same conditions, the rate of dissipation of ethofluralin was faster in yellow soil and slower in black soil and red soil.

Influence of environmental conditions on the disappearance time of herbicide toxicity*
Environmental conditions such as temperature, humidity, and light also affect the rate of herbicide dissipation and holding period in soil. For example, some herbicides are rapidly hydrolysed in moist soils and have shorter dissipation half-lives. In addition, if rain occurs in the middle of the day, the disappearance time of the toxicity of the herbicide will also be much shorter.

In summary, the disappearance time of herbicide toxicity in soil depends on a variety of factors, including herbicide type, soil type, and environmental conditions. These factors need to be taken into account when using herbicides to ensure the safety of crops and the environment.