菌渣还田对中国北方农牧交错带农田土壤生境的影响

[Objective]As part of the ecological barrier and food security,the agro-pastoral ecotone is vital in the northern China.Since soil fertility in northern China is low due to frequent surface disturbances,there is the potential to actively.soil properties.Exploring the effect of fungal residue return on soil properties will help reduce the fertilizer used in areas with weak productivity and ultimately achieve green agriculture.[Method]The test materials were waste fungal residue and organic fertilizer(chicken manure,cow manure)that were fermented and completely decomposed.Before returning to the field,the fermented fungal residue was packed into packaging bags for easy transportation(30 per package).The waste fungal residue was evenly distributed on the soil surface during the spring tilling period in 2019.A rotary cultivator was also used to apply the fertilizer to the layer between 0-20 cm.After three consecutive years,the fields were planted with locally adapted naked oat.The experiment was based on a long-term dry farmland observation station.Six concentrations of fungal residue were selected for the pre-experiment.We used different concentrations of soil samples from the 0-30 cm soil layer(10 cm unit)to compare the differences in soil properties.[Result]Fungal residue return ositively impacted soil bulk density,porosity,and moisture content.The range of soil bulk density under different returning concentrations was 1.12-1.59g/cm3.Adding fungal residue to the field was better in increasing soil parameters(SOM,and AP),and this characteristic effect continued as the return concentration increased.However,changes in the soil porosity were not apparent.With the increase in return concentration,the amount of bacteria and actinomycetes first increased and then decreased,and fungi showed a continuous increased.Except for the number of actinomycetes fungal residue return significantly increased microbe numbers only in the 0-10 cm and 10-20 cm layers.Soil urease(SU),soil sucrase(SS),and soil alkaline phosphatase(SAP)were selected to characterize the effect of fungal residue inputs on soil enzymes.The activities of soil urease and soil sucrase decreased with the increasing soil depth,but soil alkaline phosphatase showed a trend of first decreasing and then increasing with depth.In the soils under fungal residue treatment,the soil enzyme activities were superior to those of CK,and the activities of SU,SS,and SAP,increased to 4%-49%,3%-63%,and 3%-77%,respectively.[Conclusion]Fungal residue return improved soil physical structure,and increased aeration,and water permeability,and this effect increased with increasing residue concentration.The effect of mushroom residue return to the field on porosity was relatively small,which only increased by 12.12%.Addition of fungal residue to the field was better in increasing soil parameters(SOM and AP),and this effect increased as the return concentration increased.Compared with CK,the number of bacterial,fungi,and actinomycetes increased by 1.94 times,1.46 times,and 1.71 times,respectively.Under the conditions of R11,the soil urease activity was the highest.The trend of sucrase activity in the different soil layers was inconsistent.AK was strongly correlated with the other factors,and the microorganisms and enzyme activiies were strongly associated(P<0.01).