| With the development of vegetable production,the number of vegetable straw is increasing.Vegetable straw is rich in mineral elements and high in organic matter,but there are problems such as time-consuming and labor-consuming treatment methods and low level of resource utilization.In recent years,with the research and development of the in-situ returning machinery of facility vegetable straw and the research and development of the decomposition agent of facility vegetable straw,the in-situ returning technology of facility vegetable straw has been gradually promoted and applied.However,there is still a lack of systematic research on the decomposition of straw and its effect on soil organic carbon during the in-situ returning of facility vegetable straw.The field experiment was carried out in 2021,Three straw returning treatments were set up,namely,no straw returning(CK),straw returning(NK)and straw returning with microbial agent(TJ);three treatments,i.e.,straw 9 g(JG),straw 9 g + soil 50 g(JT)and straw 9 g + soil 50 g + microbial agent 2 g(JTJ),were set up to simulate the indoor experiment.Through field experiments and indoor simulation experiments,the characteristics of straw decomposition,soil chemical properties,soil organic carbon,soil enzyme activity and soil microbial community structure were comprehensively analyzed,and the effects of in-situ returning of facility vegetable straw on soil quality were analyzed.It is expected to provide basic theory and technical support for the study of resource utilization of facility vegetable straw.The main results are as follows:1.The straw decomposition rate,cellulose decomposition rate and hemicellulose decomposition rate of NK treatment reached 50.49 %,24.24 % and 41.52 % after 20 days of in-situ returning of facility vegetable straw,and TJ treatment reached 55.91 %,30.74 % and 46.59 %.After 140 days of simulated vegetable straw decomposition,the straw decomposition rate,cellulose decomposition rate and hemicellulose decomposition rate of JT treatment can reach 64.58 %,33.51 % and 44.27 %,and JTJ treatment can reach 67.43 %,47.75 % and 49.87 %.The addition of microbial agents to the in-situ returning of facility vegetable straw significantly promoted the decomposition of vegetable straw.2.The contents of soil organic carbon and hot water extractable carbon were significantly increased by 13.31% and 17.99%,respectively.After adding microbial agents,the contents of soil organic carbon and hot water extractable carbon were significantly increased by 21.07% and 26.81%,respectively.In the simulation experiment,the soil organic carbon,dissolved organic carbon and hot water extractable carbon in the 140 days treatment were significantly increased by 167.07%,62%and 36.25%,respectively,compared with the 5 days treatment,and the JTJ treatment was significantly increased by 178.42%,94.15% and 57.97%,respectively.The response of hot water extractable carbon to straw returning was more obvious than that of organic carbon.The fluorescence contribution rate of humus-like substances in straw returning treatment was significantly higher than that in straw removal treatment in three-dimensional fluorescence spectroscopy.3.The contents of soil organic matter,nitrate nitrogen,ammonium nitrogen and available potassium were significantly increased by 23.7%,19.9%,23.02% and 45.77%,respectively.After adding microbial agents,the contents of soil organic matter,nitrate nitrogen,ammonium nitrogen and available potassium were significantly increased by 34.99%,68.36%,34.59% and 51.99%,respectively.At the same time,the soil p H was reduced by 0.07-0.12 units,and the soil fertility was improved.The activities of soil catalase(13.01%),urease(17.18%),cellulase(47.92%)and β-glucosidase(22.25%)were significantly increased by in-situ returning of greenhouse vegetable straw compared with no returning treatment.The relative abundance of soil Ascomycota,Proteobacteria and Actinobacteria increased by 14.96%,8.28% and 16.27%,respectively,after insitu returning of greenhouse vegetable straw.The relative abundance of Basidiomycetes,Acidobacteria and Gemmatimonadetes was significantly reduced by 37.45%,25.12% and 13.39%,respectively.During the growth process,tomato plants were investigated every 30 days,and no disease occurred in tomato plants.Therefore,the in-situ returning of facility vegetable straw did not increase the level of plant disease.In summary,the in-situ returning of facility vegetable straw significantly increased soil fertility,significantly increased soil organic carbon content,increased soil enzyme activity,improved microbial community structure,and rationally added microbial agents and stuffy sheds.Optimizing the in-situ returning method of facility vegetable straw is a scientific agronomic measure.Therefore,the in-situ returning of facility vegetable straw is a convenient,green and safe straw resource utilization technology,which has broad application prospects. |
PDF Full Text Request