Effect Of Paraquat And Glyphosate On The Amount Of Microorganisms And The Activities Of Enzymes In Purple Soil

Pesticides can effectively protect the agricultural harvest, and it is essential for agricultural production. Since the emergence, pesticides have been widely used to provide effective protection for agricultural development all over the world. Pesticides play an important role in agricultural production, but the loss of pesticides cause pollutions and dangers to environmental elements, including human, animal, environmental biotechnology, water, air, soil, and so on. With the development of the society, people are increasingly concerned about environmental issues; the impact of pesticides to the environment has also attracted people's great attention. Countries around the world regulate the production of pesticides, and develop a rapid and convenient inspection technique for pesticide residues, thus to provide a strong basis for evaluation about environmental safety of pesticides. Environmental safety assessment of pesticides contains a huge workload. This study observed the effects of soil microbial quantity and enzymes of purple soil affected by paraquat and glyphosate, and provide the necessary data of overall safety evaluation for these two herbicides.The main results are as follows:1. Paraquat has inhibitory effect on soil bacteria, actinomycetes and fungi of potted wheat. After 1 day's treatment with 10～40 mg/kg of paraqua, we can have inhibition rates on actinomyces qty were 31.9%,41.1%,31.0%. And on day 4, the inhibition rates of bacteria qty reached their maximum levels, which were 37.6%,51.4%, and 64.4%. Treatment with 10mg/kg of paraquat on dayl received a highest inhibition rate on then number of fung, which was 27.8%.2. Paraquat has significant inhibitory effect on soil bacteria, actinomycetes of potted cabbage, and has certain stimulation on fungi of potted cabbage. The higher the concentration of paraquat was used, the more obvious inhibition rate on bacteria we got. For impact on actinomycetes, there was no significant difference when using in different concentrations of paraquat.3. Glyphosate on has obvious inhibitory effect on soil bacteria, actinomycetes of potted wheat, and has certain stimulation on fungi of potted cabbage. The higher concentration of paraquat was used, the stronger inhibition effect on bacteria we go inhibition t, and actinomycetes did the opposite.4. Glyphosate has inhibitory effect on soil bacteria, actinomycetes and fungi of potted cabbage. Different concentrations of glyphosate on the bacteria, actinomycetes and fungi have different inhibitory effects, which can be described as:80mg/kg> 20mg/kg> 40mg/kg. The higher concentration of paraquat was used, the stronger inhibition effect on fungi we got.5. Paraquat showed strong inhibition on catalase activity of potted wheat and cabbage soil. In the 7th day, the inhibition rate reach maximum of 39.0%～56.5% after application of different concentration's paraquat. The Influence of paraquat on catalase activity is initially inhibitory and then recovery. Glyphosate's influence on catalase activity in soil has the same trend with paraquat, and has comparatively low impact.6. Paraquat's influence on urease activity in soil has the same trend with influence on catalase activity.20 mg/kg of glyphosate on day 1 have a slight stimulus on soil urease activity of potted cabbage, and 40 mg/kg on day 4 of glyphosate have a slight stimulating effect on soil urease activity of potted cabbage, and in the 13th day,20 mg/kg of glyphosate have a slight stimulating effect urease activity in soil of wheat plants.7. The influence of paraquat on acid phosphatase activity had a trend of initially inhibition and then stimulation. Glyphosate's influence on acid phosphatase activity in soil was trend begins with inhibition then to recovery, but recovery is slow.