关键词: 免疫效果, 免疫效果

Abstract: 【Objective】The objective of the experiment is to study the effect of apple orchards with different planting years on soil physical-chemical properties and activities of Soil eneyme.【Method】Soil samples were taken from apple orchards with different years of planting in Jixian,whose soil physical-chemical properties and activities of soil enzyme,and the correlativity between soil physical-chemical properties and activities of soil enzyme was analysed at the same time.【Result】With the time of planting increasing,the content of soil organic matter,available P,Cu,Zn,Mn and water-soluble salt firstly declined and then increased in different depths of soil layers(0-20cm,20-40cm,40-60cm)in apple orchards;the soil available K and total N had a firstly decreasing and then increasing trend in upper layer(0-20cm),which was as the same tendency as in middle layer(20-40cm);the soil available Fe firstly declined and then increased in upper layer (0-20cm).The activities of urease, invertase had a same trend with soil nutrients in different depths of soil layers,and the activity of catalase had a significant correlation with soil organic carbon, organic matter and available P.【Conclusion】With the time of planting increasing, soil nutrient content generally renders the phenomenon which decline in early growth stage and then rose in full bearing period, which was related to attention degree of the local fruit growers at different periods.The fruit growers should strengthen the fertilization management in early growth stage of fruit trees.Soil enzyme activity was greatly affected by soil physical-chemical properties, especially by available P, organic matter content and other factors.The activities of enzymes can be used as a means of evaluating soil biological activity and characterizing soil fertility levels in apple orchard.