Modification Of Cotton Stalk Carbon And Its Biological Effect

Gray desert soil is the main agricultural soil in northern Xinjiang.Its low yield characteristics of "white,flat and dry" soil make nitrogen fertilizer can not be fully utilized.Biochar plays an important role in agricultural and environmental fields such as low-yield soil improvement,crop increase,remediation of soil pollution and greenhouse gas emission reduction.In this study,biochar was compounded with other materials to change the physical,chemical and biological properties of biochar,and to form functional biochar materials with new properties and structures.Xinjiang cotton accounts for nearly 80% of the planting area of the country,and returning the cotton straw directly to the field may lead to the increase of soil-borne diseases and affect the cultivation of the next year.However,it is a new way to improve the fertility of cotton straw after carbonization and modification into the soil.This study based on gray desert soil of xinjiang,of the tested soil for agricultural processing waste acid modified materials,will be modified,cotton stalk carbon,by adopting the method of indoor culture and analysis of cotton stalk carbon properties before and after modification,and modification of cotton stalk carbon into the gray desert soil,the soil characteristics,the influence of wheat yield and nutrient,clear modified cotton stalk carbon modified gray desert soil and its effect,The results provided the basis for improving low yield soil with cotton stem carbon.The main research results of this paper are as follows:(1)The physical,chemical and biological properties of cottonstalk carbon were improved by compound modification of cottonstalk carbon with monosodium glutamate waste solution,wood vinegar solution and tartaric acid solution.The p H value of cotton stalk carbon can be significantly reduced by using three modified materials.FTIR analysis showed that compared with the original cotton-stalk carbon,the acid functional groups on the surface of the modified cotton-stalk carbon increased.Scanning electron microscopy(SEM)results showed that there were obvious pore structures on the surface of tartaric acid modified carbon,but there were no obvious pore structures on the surface of monosodium glutamate waste liquid modified carbon and wood vinegar modified carbon.(2)The indoor static culture experiment of ammonia volatilization of nitrogen fertilizer showed that the main stage of ammonia volatilization was 1-8 days after nitrogen application,and the cumulative amount of ammonia volatilization accounted for more than 90% of the total amount of ammonia volatilization in this stage.AN200 treatment(monosodium glutamate waste liquid modified carbon +200 mg·kg-1 nitrogen fertilizer)could significantly reduce the ammonia volatilization rate of ash desert soil.The total nitrogen content of the modified carbon was increased by 73.65%,79.25% and 81.95%,respectively,compared with CK.The soil organic matter content was 8.00 ~ 23.97 g·kg-1.Compared with the basic soil organic matter content(8.00g·kg-1),the organic matter content of all the groups treated with modified carbon and nitrogen fertilizer was significantly increased than that of the group treated with unmodified carbon and nitrogen fertilizer.(3)Wheat was planted on the basis of applying modified cottonstalk carbon into ash desert soil.Soil analysis after wheat harvest showed that the application of both unmodified cottonstalk carbon and modified cottonstalk carbon significantly reduced the p H value of ash desert soil.The electrical conductivity of all treatments was higher than CK(without nitrogen fertilizer and without cotton stalk carbon).In particular,the conductivity of AN0,AN200 and AN400 were 2.28,2.09 and 2.41,respectively,in the modified carbon treatment group(p <0.05).Monosodium glutamate waste solution modified cotton-stalk carbon did not promote wheat growth with the increase of nitrogen content,but the soil total nitrogen content was the highest.(4)Pot experiment showed that the biomass of wheat did not increase with the increase of nitrogen application level.The yield of wheat was the highest at 400 g·kg-1 under all fertilization methods except for monosodium glutamate waste liquid modified carbon treatment.Under N0,N200 and N400 levels,the biomass of wheat under MN400,TN400,TN200,JN400 and WN400 treatments was 17.84,17.25,16.42,16.11 and 15.73 g,respectively.The yield of MN0,WN0,TN0,JN0 and AN400 treatments was the lowest,which were 3.79,5.3,5.48,5.84 and 9.29 g,respectively.In conclusion,the shortcomings of high p H,low nutrient content and low porosity of cotton stalk carbon can be improved through three kinds of modified materials.The application of modified cotton-stalk carbon into soil can effectively increase the content of organic matter and total nitrogen in soil and reduce the p H value of ash desert soil,so as to improve the fertility of ash desert soil significantly and promote the growth of wheat.When biochar was modified with monosodium glutamate waste solution,soil p H value was significantly decreased by 0.17(p <0.05)and soil salt content was significantly increased by 0.73(p <0.05).The contents of organic matter and total nitrogen increased the most,and wheat biomass was the highest,which had the best improvement effect on xinjiang gray desert soil.