Effects Of Organic Fertilizer On Soil Physicochemical Properties And Enzyme Activities In Continuous Cropping Peanut Field

Peanut is one of the main economic crops in northwest Liaoning Province.With the continuous expansion of planting area and years,the soil quality declined and serious yield reduction arised.In this paper,the peanut field with continuous cropping for 5 years was selected for experimental field,and four treatments are carried out,which are: wormcast + chemical fertilizer(VM)、bio-organic fungus fertilizer + chemical fertilizer(BF)、chemical fertilizer(CF)and contrast without fertilizer(CK),the effects of organic fertilizer on the soil physical and chemical properties and enzyme activity were tested,The results will provide scientific basis for soil ecological restoration、soil quality improvement and improvement of peanut continuous cropping obstacles.The main results were as follows:(1)Compared with the control and the single application of chemical fertilizer,organic fertilizer combined with chemical fertilizer could significantly reduce the soil bulk density at pod setting stage and harvest stage,and increase the soil p H、organic matter、total nitrogen、alkali-hydrolyzable nitrogen、total phosphorus、available phosphorus、total potassium and available potassium contents at pod setting stage and harvest stage(P<0.05),and vermicompost organic fertilizer combined with chemical fertilizer had the best effect.Soil bulk density decreased by 5.96～6.12% compared with the control,soil p H、organic matter、total nitrogen、alkali-hydroly zable nitrogen、total phosphorus、available phosphorus、total potassium and available potassium increased by3.07～6.17%、19.95～21.04%、21.59～163.94%、82.11～94.87%、80.39～87.93%、5.20～ 14.53%、70.68～75.02% and 43.44～62.86%,respectively,compared with the control.(2)Compared with the control and the single chemical fertilizer,the activities of soil sucrase、lipase、protease、urease、phosphatase and catalase in podding stage and harvest stage were significantly increased by organic fertilizer combined with chemical fertilizer(P<0.05),and vermicompost organic fertilizer combined with chemical fertilizer had the best effect.The six soil enzyme activities increased by10.74～19.44%、71.58～77.22%、22.48～23.24%、47.24～51.00%、36.52～36.94% and 30.65～30.74% compared with the control,respectively.(3)The soil nutrient indexes and enzyme activity indexes were higher in podding stage than in harvest stage.The AN/TN、AP/TP and AK/TK ratios in different treatments were different at pod setting stage and harvest stage,there were significant differences in the ratio between four fertilizer treatments and two different periods,which could reflect the supply capacity of nitrogen,phosphorus and potassium.(4)Correlation analysis showed that,soil total nitrogen、alkali-hydrolyzed nitrogen、total phosphorus、available phosphorus、total potassium、available potassium were significantly positively correlated with soil enzyme activities(P<0.05 or P<0.01);Soil p H was significantly positively correlated with the activities of soil organic matter、total nitrogen、total phosphorus、alkali-hydrolyzed nitrogen 、available phosphorus 、available potassium 、 sucrase、lipase、phosphatase and catalase(P<0.05 or P<0.01),but not correlated with the activities of soil total potassium、protease and urease;Soil organic matter was significantly positively correlated with total nitrogen、total phosphorus、available phosphorus、available potassium、sucrase、lipase、phosphatase and catalase(P<0.05 or P<0.01),but not correlated with the activities of alkali-hydrolyzed nitrogen、total potassium、protease and urease.There are 21 figures,10 tables and 173 references in this paper.