Location Experiment Study On The Effect Of Rotten Straw On The Ecosystem Of Corn-wheat Rotation Field

With the long-term application of chemical fertilizers,the soil fertility of farmland has been exhausted,and excessive application of nitrogen fertilizer leads to high pollution,high consumption and low output.Rational use of agricultural waste such as straw and reducing the amount of nitrogen fertilizer applied are of great significance to the protection of agricultural ecological environment.Based on the background of the third year of the positioning experiment,this study investigated the effects of different proportions of fertilized wheat straw under aerobic composting on the summer maize-winter wheat rotation field under different nitrogen conditions.The main research work completed is as follows:(1)Study on the effect of adding microbial preservative on aerobic composting of wheat straw.The pH values of the treatment 1 and treatment 2 pile materials reached 8 and 7.4,respectively,which were higher than CK treatment;the seed germination rate of the treatment 1 and treatment 2 pile materials reached 87%and 90%,respectively,reaching the complete maturity standard;The total nitrogen content of the treated and bulk materials exceeds 16 g·kg-1.The results showed that compared with the addition of microbial preservative,the addition could significantly improve the efficiency of maturity and quality of wheat straw,and greatly shorten the time of straw maturity.(2)The effect of different proportions of decomposed straw on the growth index and yield of winter wheat under different nitrogen conditions.By comparing the differences in plant height,chlorophyll,leaf area index,photosynthetic index,biomass and yield of each treatment,the results showed that compared with single application of chemical fertilizer,under the condition of nitrogen,the proportion of decomposed straw exceeded 50%(excluding 50%).Substituting fertilizer significantly reduced the plant physiological index and yield index of winter wheat.The difference between 20%and 50%and single application of chemical fertilizer was not significant.The results were close to the previous year.The comprehensive results showed that the replacement of chemical fertilizer with 50%of decomposed straw contributed to winter wheat.Growth and yield increase.(3)Under different nitrogen conditions,the effects of different proportions of decomposed straw on the structure of arthropod community in winter wheat.By comparing the number of arthropod species and the number of individuals in each treatment,the effects of decomposed straw returning on the stability of arthropod functional groups and arthropod community were investigated.The results showed that compared with single application of chemical fertilizer,decomposed straw replaced fertilizer.The proportion of more than 50%(including 50%)significantly reduced the number of individual insect functional groups,20%to 50%of the difference with single application of chemical fertilizer is not significant;the proportion of decomposed straw replacement fertilizer does not exceed 50%(including 50%)significantly increased The number of species and the number of individuals of the predatory natural enemies functional group,the proportion of 20%to 50%and the single application of chemical fertilizers were not significant.Compared with single application of chemical fertilizer,the replacement of chemical fertilizer by 50%of mature straw significantly increased the diversity and evenness index of arthropod community;the proportion of decomposed straw replacement fertilizer did not exceed 50%(including 50%),which significantly promoted the stability of arthropod community.The difference between 20%and 50%and single application of chemical fertilizer is not significant.The comprehensive results show that replacing 50%of the mature straw with fertilizer can improve the complexity of the habitat structure and species richness,and promote the stability of farmland ecosystem.(4)The effect of different proportions of decomposed straw on the growth index and yield of summer maize under different nitrogen conditions.By comparing the differences in plant height,chlorophyll,leaf area index,photosynthetic index and yield of each treatment,the results showed that compared with single application of chemical fertilizer,more than 80%of the decomposed straws(excluding 80%)replaced the chemical fertilizer under the same nitrogen conditions.The physiological indexes and yield indexes of summer maize were significantly reduced,and the difference between 20%and 80%was not significant.The comprehensive results showed that the replacement of chemical fertilizer with 80%of the mature straw contributed to the growth and yield of summer maize,and the result was better than that of the former crop.(5)Under different nitrogen conditions,the effects of different proportions of decomposed straw on the soil nutrient index of summer maize-winter wheat rotation field were studied.By comparing the differences of soil nutrient contents in the whole summer maize-winter wheat growth period,the results showed that compared with single application of chemical fertilizer,more than 80%(including 80%)of the decomposed straw replaced the chemical fertilizer against summer corn under the same nitrogen condition.The soil organic matter content in the growth period was not significantly increased.The 80%replacement of chemical fertilizer did not significantly increase the soil available potassium content during the growth period of summer maize.Under the condition of nitrogen,the soil nutrient content of each treatment at the end of the experiment increased compared with the initial stage of the experiment,and the 50%ratio of the decomposed straw replaced the chemical fertilizer to improve the soil nutrient content of the whole winter wheat-summer maize growth period.Summer maize has higher utilization rate of organic matter in decomposed straw than wheat.