Research On Soil Physical-Chemical Properties And Activities Of Soil Enzyme In Apple Orchards With Different Planting Years

The thesis makes a research about the soil of apple orchardswith different years of planting at Ji County of Shanxi province, inorder to determine the physical-chemical properties and activitiesof soil enzyme from the trunk to the different range of the surfaceand the different depth of the profile soil, then analyze its variationlaw and the mutual relationship. The main results are as follows:(1) Organic matter and Total N are low in the study area,available P and available Zn are insufficient in some areas, but thecontent of soil available K, Cu, Fe and Mn are higher. The lack ofnutrition elements which are soil organic matter, N,P and Zn in thestudy area, has become one of the important factors influencing thelocal fruit growth and yield and quality improvement.(2) The surface soil test results of physical-chemical propertiesfrom the trunk to the different range in the study area indicated that:With increased planting years,the content of surface soil moisturefirstly declined and then increased；compactness also showed thesame change trend;<0.01mm diameter show a declining trend;organic matter, total N, available K, Cu, Fe, Zn and Mn was firstlydecreased and then increased; which was related to attentiondegree of the local fruit growers at different periods, The fruit growers should strengthen the fertilization management in earlygrowth stage of fruit trees.(3)The physical-chemical properties of different depth soil instudy area showed: With the time of planting increasing, the contentof soil moisture firstly declined and then increased in differentdepth soil; compactness showed the first decline after rising trendin0-20cm, but in the20-40cm and40-60cm firstly increased andthen decreased;<0.01mm diameter showed a declining trend in the0-20cm, while in20-40cm increased firstly and then decreased,in40-60cm on the rise; the content of organic matter, available P, Cu,Zn, Mn and water-soluble salt showed the first decline after risingtrend in different depth of soil; Available K and total N also showedthe first decline after rising trend in0-20cm and20-40cm,the sameas Available Fe in0-20cm. Further indicate that farmers shouldenhance the fertilization management of young fruit trees.(4) Activity of Surface soil enzyme from the trunk to thedifferent range in the study area showed: With increased plantingyears, the activity of urease decreased in0-60cm, while60-120cmand120-180cm was rising after falling trends; the activity ofinvertase showed a decline after an upward trend in different rangefrom the trunk; the activity of catalase firstly declined and thenincreased in0-60cm, while in60-120cm and120-180cm showed afirstly decreasing and then increasing trend.(5) Soil enzyme activity in different depth of soil showed: Withthe time of planting increasing, the activity of invertase showed adownward trend; the activity of Urease was decreased in0-20cm,but firstly decreased and then increased in20-40cm and40-60cm; the activity of catalase was firstly increased and then decreased in0-20cm and20-40cm, but in40-60cm showed a firstly decreasingand then increasing trend. It showed that the activities of soilurease, Invertase, catalase increase were on a downward trendwith increased planting years in the0-20cm, the growth barriers offruit trees were more visible,while the soil enzyme activity wasinconsistent in20-40cm and40-60cm. This may be related to rootdistribution and management mode of the apple trees, the specificreasons require further research.(6) With increased planting years, Soil enzyme activity ofsurface and different depth was greatly affected by soilphysical-chemical properties, especially by available P, organicmatter content and other factors.The activities of enzymes can beused as a means of evaluating soil biological activity andcharacterizing soil fertility levels in apple orchard.