Effects of Straw Returning to Field on Soil Physicochemical Properties and Enzyme Activities During Freeze-thaw
In order to further improve the decomposition rate of rice straw and improve the physical and chemical properties of the soil in the Sanjiang Plain.This study used indoor freeze-thaw simulation experiments,with experiment setting A(-10～10℃)and B(-20～20℃)as two freeze-thaw amplitudes,1(150%)and 2(200%)as two soil moisture holding capacities,and 3(3 cm),5(5 cm),and 10(10 cm)as three straw lengths.The experiment set freezing for 24 hours followed by thawing for 24 hours as one freeze-thaw cycle process,sampling once every 15 days,with a total of 6 samplings taken(90 days)followed by room temperature incubation(30 days),for a total duration of 120 days of indoor freeze-thaw simulation.Soil physical and chemical properties and related enzyme activities were determined after each freeze-thaw cycle.The test results show that the application of microbial agents increased the rate of straw decomposition,straw application of microbial agents significantly reduced the soil bulk density and the number of aggregates of 0.5～1 mm particle size during the freezing-thawing period in the Sanjiang Plain,increased soil porosity,with the greatest effect observed in the large amplitude freeze-thaw cycles.Straw application significantly increased soil organic carbon(TOC),total phosphorus(TP),and total potassium(TK),but significantly decreased soil total nitrogen,with no significant differences observed among different freeze-thaw amplitudes.Straw application with microbial agents significantly increased the activities of soil amylase,sucrase,and cellulase during the freezing-thawing period,while different freeze-thaw amplitudes and the number of freeze-thaw cycles had an impact on soil enzyme activities,which decreased with the increase in freezing-thawing duration.Different freeze-thaw amplitudes and soil moisture holding capacities significantly affected soil amylase activity,but had no significant effect on soil sucrase activity.Straw application with microbial agents had a significant impact on the physical and chemical properties of the soil during the freezing-thawing period,with differential effects on soil enzyme activities.Therefore,straw application with microbial agents is of great importance for improving soil fertility during the freezing-thawing period in the Sanjiang Plain.
low temperature bacteriasoil physicochemical propertiesfreeze-thaw periodsoil enzyme activity
万方数据
维普
