Effects Of Rice Straw Dosage On Fruit Body Quality Of Stropharia Rugosoannulata And Soil Properties Under Forest

Stropharia rugosoannulata is a kind of grass-decay fungus,which can degrade straw very well and can transform straw into nutrients which can be used by plant and soil microorganisms.The cultivation of Stropharia rugosoannulata under forest can not only increase soil nutrients,improve microbial community,increase the number of soil beneficial bacteria,enhance tree vigor and other functions,but also provide good economic benefits.In this paper,Stropharia rugosoannulata with high efficiency of rice straw degradation was used as the research object.Stropharia rugosoannulata was planted under the plantation with different rice straw amounts.The differences of protein and amino acids in the fruiting bodies of Stropharia rugosoannulata with different straw treatments were determined by automatic Kjeldahl Nitrogen Analyzer and automatic amino acid analyzer,the dynamic effects of soil organic matter,main nutrient elements（N,P,K）and soil enzyme activities in the forested soil were studied.And the effect of Agrocybe giganteum planting under forest on soil micro-organisms was studied by high-throughput sequencing.The purpose of this study was to explore the optimum amount of rice straw for the cultivation of Stropharia rugosoannulata under the“Forest-fungus”cultivation mode,and to provides a healthy and sustainable development plan for the economic development under forest in Shanghai.The main results are as follows:（1）The content of protein and hydrolytic amino acid in fruiting body of Stropharia rugosoannulata was different with the amount of rice straw used.Different treatments were marked as SA,SB,SC,SD and SE groups according to the amount of straw used:10 kg·m^-2,20 kg·m^-2,30 kg·m^-2,40 kg·m^-2and 50 kg·m^-2.The contents of crude protein in the fruit bodies of SA,SB and SD were higher than those in SC and SE.The contents of SA,SD and SE in hydrolyzed amino acids were higher.At the same time,the amino acid composition of Stropharia rugosoannulata varied with the amount of rice straw used.The values of AAS,IOM,CS and EAAI were the highest in SE group,while the values of E/T,proximity,PDCAAS and SRC were higher in SA group than in SE group.SC group had higher scores on E/T than SE,SD group had higher scores on closeness and SRC than SE.And SB group had lowest scores in all scores.In addition,according to the scores,there was a significant shortage of threonine and a relative surplus of L-isoleucine in the essential amino acid of Stropharia rugosoannulata.（2）The residue of Stropharia rugosoannulata could not significantly increase the content of organic matter and organic carbon in the upper soil layer,but could significantly enhance the lower soil layer.And it can reduce the content of water-soluble total salt in the soil under the forest and improve the salinization of the soil.It also can significantly increase the contents of total N,total P,total K,available N,available P and available K in the soil,the promotion of available N,available P and available K is more obvious than that of total P,total N and total K.The change trend of the same enzyme activity in each group was relatively consistent.Compared with the control,the changes of alkaline xylanase,polyphenol oxidase and cellulase activities in soil under forest were not significant after planting Stropharia rugosoannulata,and the activity of cellulase in the lower soil of SA and the upper soil of SE increased significantly.The activities of catalase,sucrase andβ-glucosidase increased with the increase of straw application,the promotion of enzyme activity in upper soil was more obvious than that in lower soil.The dehydrogenase activity in the upper soil increased with the increase of straw amount,but it did not increase significantly compared with the control.The dehydrogenase activity in the lower soil decreased first and then increased with the increase of straw amount,and got the remarkable promotion;The activity of soil laccase decreased with the increase of straw application,and the increase of laccase activity in the lower layer was more obvious than that in the upper layer.（3）The results of high-throughput sequencing showed that the bacterial diversity and abundance in the soil increased significantly when the rice straw was used in medium amount,but decreased when the rice straw was used in low amount,the bacterial diversity level and bacterial abundance in SA treatment group decreased significantly.After planting Stropharia rugosoannulata,the level of fungal diversity in the soil under the forest decreased,and the decrease was significant when the amount of rice straw used was medium.Except for SA,the fungal community abundance in the other soil groups increased significantly,and increased with the increase of straw application.The structure of bacterial community and fungal community in the soil under the forest changed,and the differences among the treatments were significant.Proteobacteria and Bacteroidota could increase the content of N,P and K in the soil,and Verrucomicrobiota could promote the degradation of lignocellulose,their abundance in the treatment group increased.The abundance of Actinobacteriota,Latescibacterota and Nitrospirota,which could reduce nitrogen,phosphorus and potassium in soil,showed a decreasing trend in the treatment group.After the cultivation of Stropharia rugosoannulata,the abundance of Actinomycetes in the lower soil increased,and the antibiotics produced by the Actinomycetes might inhibit the diversity of soil fungi,resulting in the degradation of cellulose in the soil,resulting in the reduction of soil organic matter.Considering the effect of the amount of rice straw on the quality of fruiting body of Stropharia rugosoannulata and the properties of forest soil,the optimum amount of rice straw for the cultivation of Stropharia rugosoannulata was 30-40 kg·m^-2.