Effects Of Biochars In Black Soil On Physiological Characteristics Of Maize Seedlings Under Atrazine Stress

Atrazine is widely used as a selective herbicide in the black soil region of northeastern China.While controlling weeds,it has long-term stability and can be easily degraded in deep soil due to its stable nature.A large amount of residual atrazine can migrate in the soil,and entering rivers poses a direct threat to human health.It can also lead to potential risks to the human body through the food chain through the absorption and utilization of plants.Atrazine has a long half-life,so effective governance and mitigation of its risks to the environment have become an important issue of immediate concern.Biochar is a functional material with a wide range of pores and high aromatization degree.Due to its low price,good performance,ease of production,and ease of use,it has made outstanding contributions in recent years in the ability to repair and improve soils,increase crop yields,and reduce the accumulation and migration of pesticides in soils and crops.To further analyze and understand the effects of biochar on seed germination,vegetable crop growth,physiology,and ease of plant-to-pesticide accumulation.The effects of biochar with different pyrolysis temperatures on seed germination,seedling growth and physiological characteristics of maize under atrazine stress were studied.The experimental results are as follows:Under the anaerobic environment,biochar has different influence on the structure and properties of biochar under different pyrolysis temperatures.The low-temperature biochar has more functional groups.With the increase of pyrolysis temperature,the ash,pH,and carbon content of the biochar significantly increased,and the carbon frame structure became more stable.The higher temperature promotes the aroma of biochar,the aliphatic function gradually disappears,and the polarity decreases.At the same time,high temperatures greatly increase the number of micropores and specific surface area of biochar.With the increase of the concentration of atrazine stress solution,the seed germination rate of corn gradually decreased.Under the effect of atrazine(30-50 mg/L),the application of biochar can significantly increase the germination rate.In particular,the effect of high-temperature biochar on seed germination is more pronounced.The application of four doses of biochar with different temperatures in the soil of atrazine contaminated soil(50 mg/kg)was conducted in a pot experiment.When the application amount of biochar was ?0.5%,the effect on plant height of maize seedlings was not significant.When the application amount was 1%,the plant height of the BC250,BC550,and BC8500 treated groups was significantly increased by 9.74%,17.37%,and 24.43% compared with the control.The gradual increase of the biochar application rate promoted the accumulation of biomass in the plant.In the application of 0.5% to 1%,the three kinds of biochar significantly increased dry matter accumulation.Applying a small amount of medium-low temperature biochar can promote root enlargement and dry matter accumulation in the roots.With continued use,the root to shoot ratio decreases significantly when the amount of application is >0.5%.The three groups of biochar treatment played a more obvious role in accelerating the accumulation of dry matter in aboveground parts.The ratios of root to shoot of BC250,BC550,and BC850 were reduced by 62.98%,57.92%,and 58.96% respectively compared with the control.The differences among the three groups were not significant.Increased application of biochar can significantly increase the content of chlorophyll and carotenoids in the body and promote the photosynthesis of the value.Atrazine caused membrane lipid peroxidation of leaves and roots,and the addition of biochar,which could inhibit the production of oxidative free radicals,reduced the MDA content in leaves of BC250,BC550 and BC850 treatment groups by 48.61%,49.2% and 50.47%,respectively.And the effect of relieving the poison to the root is more obvious than the effect of the blade.In the BC250,BC550,and BC850 treatment groups,when the application amount was 0.1% to 0.5%,the proline content in the leaves increased by 118%,197%,and 207%,respectively,compared with the control,and had a good effect on the regulation of leaf osmotic pressure.At an application amount of 0.5%,the soluble sugar content increased by 68.34%,190.75%,and 177.34%,respectively.Atrazine accumulation in roots was greater than accumulation in leaves.When applied at 1%,BC250,BC550,and BC850 treatment groups had a significant effect on the accumulation of atrazine in plants,compared with the treatment group.Reduced 58.01%,59.47%,60.23%.The contents of the leaves were reduced by 58.94%,65.7%,and 67.34% respectively,which improved the safety of the crops and alleviated the toxic effects.