Effects On Soil Labile Organic Carbon And Enzyme Activity Of Mulching Phyllostachys Edulis Stands

In order to investigate effects on the content of soil organic carbon,labile organic carbon,enzyme activity and various nutrient of Phyllostachys edulis stands under different treatments of soil mulch and management,Phyllostachys edulis stands located in Huangyan District of Taizhou(Zhejiang Province)varied in mulch age from one to two years,were selected as the treated samples,while the adjacent P.edulis stands without mulch management was chose as control(CK).Based on the data of field plots,as well as experimental analysis under laboratory conditions,the content of soil organic carbon,labile organic carbon,enzyme activity and various nutrient in the depth of 0~50cm soils of different treatments were compared and analyzed.In this work,we reveal the mechanism in improving the quality of the Phyllostachys edulis by mulching the soil,further provide a reliable scientific basis to maintain sustainable management of Phyllostachys edulis stands.The main results were as follows:1.Effects of soil mulching by different years on soil labile organic carbon pool in a Phyllostachys edulis plantation(1)The soil total organic carbon(TOC),light fraction organic matter(LFOM),and easily-oxidized carbon(EOC)contents of the one year and two years treatments increased than those of control.One year soil mulching increased by 11.2%~74.2%,31.7%~196.9% and 5.0%~79.6%,two years soil mulching increased by 22.2%~90.8%,36.7%~238.5%,and 21.9%~97.5%,for TOC,LFOM and EOC than those of control respectively.(2)The ratio of WSOC to TOC in CK was higher than that in mulching treatments,while the ratio of EOC to TOC in three treatments present the rule of decreasing with the deepth of the soil layer.(3)The WSOC,EOC,and LFOM of the three different groups showed the relativity highly correlations with TOC.and The TOC,WSOC,EOC,and LFOM were significantly(p < 0.05)or extremely significantly(p < 0.01)correlated with soil nutrients in all treatments.2.Effects of soil straw mulching by cultivation way on soil labile organic carbon pool in a Phyllostachys edulis plantation(1)Soil mulching significantly increased the soil total organic carbon(TOC),light fraction organic matter(LFOM)contents of bamboo stands under both treatments.TOC and LFOM increased by 8.7%~43.8% and 22.2%~90.8%,13.2%~111.0% and 36.7%~238.5% respectively,than that of CK.The easily-oxidized carbon(EOC)in MST increased by 21.9%~97.5%,the EOC contents in MWST treatment creased 60.4%?47.5% in depth of 0~20 cm,while decreased in the depth of 20~50cm soils.(2)The ratio of soil WSOC to soil TOC in CK stand was higher than that in two treatments,the ratio of soil EOC to soil TOC in MWST treatment was higher than MST and higher than CK in depth of 0~20cm,but in depth of 20~50cm,the CK stand was higher than that in MWST and MST treatment.(3)The soil WSOC,EOC and LFOC had extremely significant correlations with soil TOC,the MST was always highest of the correlation coefficient of EOC and LFOC to TOC.3.Effects of different mulching years on enzymes and nutrients in Phyllostachys edulis plantation(1)The activities of Polyphenol oxidase and peroxidase decreased with the mulching year,and gradually decreased with the depth of soil layer.The activities of urease and sucrase increased with the mulching year,and been strongest in the depth of 10~20 cm.Compared with the CK,the activities of both the urease and sucrase under mulching were improved.(2)The nutrient contents increased with the mulching year,among them available P and available K increasing rapidly.The nutrient contents in the soil under mulching became biggest in the depth of 10~20 cm.(3)There was a correlation between soil enzyme and soil nutrient,and a negative correlation between polyphenol oxidase and total nitrogen?available P and available K in soil.Both urease and sucrase had a significant positive correlation with soil nutrient.4.Effects of soil straw mulching by cultivation way on enzymes and nutrients in Phyllostachys edulis plantation(1)Compared with the CK,The activities of polyphenol oxidase and peroxidase decreased with the mulching year,and gradually decreased with the depth of soil layer.However the activities of urease and sucrase increased.(2)The nutrient contents under mulching year increased first and then decreased,and reached the highest at 10~20 cm soil layer,there was significant differernce in MWST and MST,the mulching treatment improved the content of soil nutrient to some extent.(3)There was a correlation between soil enzyme and soil nutrient.Both urease and sucrase had a significant positive correlation with soil nutrient.But a negative correlation between polyphenol oxidase and soil nutrient.Peroxidase had a negative correlation with exchange Ca,and had no significant correlation with other soil nutrients.