| Soil biological activity of different productive level orchards in Shandong apple production areas were investigated; the effect of earthworms and effective microorganisms(EM) on the soil biological activity, the adsorption-desorption of cadmium and the growth and development of young apple trees with 2-year-old Fuji trees, 3-year-old Donghongguo apple trees and 15-year-old perennial bearing Fuji trees as materials (with Malus hupenhensis Rhed. as the apple stock) have been studied in pot or field experiments. The results are as follows.1.There are significant difference in biological activity of different types of soil. The activity of soil enzyme, the content of SMBC and SMBN were in a certain degree of correlation with the content of organic matter in orchard. Among all kinds of soil which were studied including cinnamon soil, brown soil, fluvo-aquic soil , the activity of urease and alkaline phosphatase were highest in cinnamon soil, the activity of acid phosphatase was highest in brown soil,the content of SMBC and SMBN in cinnamon soil was significantly higher than that in fluvo-aquic and brown earth soil.2. Orchard output and soil biological activity has a high correlation. The higher the yield, the greater activity of urease, acid and alkaline phosphatase, the richer content of SMBC and SMBN, which was more apparent among the same type of orchard. Generally, in super-high-yielding, high-yielding and mid-yielding orchards, qMB is more than 1, however in low-yielding,qMB is less than 1 in contrast. The ratio of SMBC and SMBN in high-yielding orchards is lower than that in low-yielding ones. The soil nitrogen is more bioavailability in high-yielding orchards, and bacterial communities consists the majority of soil microbial communities.3. The earthworms improves the biological activity of soil, but the extent of this impact was closely realeated to the type of soil. Earthworms enhanced the activity of urease, acid and alkaline phosphatase in cinnamon, brown, and fluvo-aquic soil significantly. To the increased extent, urease came to the highest in brown soil, while acid and alkaline phosphatase was in fluvo-aquic soil. The content of SMBC was increased significantly after the applied of earthworms in cinnamon and fluvo-aquic soil, thereinto the fluvo-aquic soil had higher incerased content of SMBC. The earthworms obviously increases the content of SMBN in all these three types soil, and the largest increasing range is in brown soil.4. If we introduced earthworms after the fertilization in soil, it would bring different results to soil enzyme activity depending on the different type of fertilizers and soil.Using earthworms after the fertilization in cinnamon soil, there was no significant difference in soil enzyme activity, the content of SMBC and SMBN compared with organic fertilizers and fertilizers. Introduced earthworms after the organic fertilizers used in fluvo-aquic and brown soil, the activity of urease, acid and alkaline phosphatase , the content of SMBC and SMBN were significantly higher than that in soils applied of fertilizer.5. Application of EM increased the soil's biological activity, but the extent of this impact were different depending on the type of soil. EM Significantly improved the activity of urease, acid and alkalescence phosphatase in cinnamon soil, and enhanced the activity of urease, acid phosphatase in fluvo-aquic and brown soil. Thereinto the activity of urease has the highest increased in cinnamon soil, while the acid phosphatase was in fluvo-aquic soil. Application of EM increased the content of SMBC in cinnamon and fluvo-aquic soil, then the larger increasing range is in fluvo-aquic soil. It also increased the content of SMBN in three types of soil, and the largest increasing range was in brown soil.6. Under different fertilizing conditions, EM had different effects on the activity of soil enzyme and the content of SMBC and SMBN. After treated cinnamon soil with EM and organic fertilizers , compared with fertilizers, application of organic fertilizers significantly increased the activity of urease and alkaline phosphatas. Under"EM + organic fertilizers"treatment the activities of soil enzyme was highest in three types of soil. After treated by EM, the content of SMBC was much higher when organic fertilizers were added to these soils,.And after used organic fertilizers, the content of SMBN in brown and cinnamon soil was significantly rised.7. The participation of earthworms and EM in cinnamon, brown and fluvo-aquic soil enhanced the activity of root of young apple trees, increased the number of root tips, the length of roots, the surface area and volume of roots , accelerated the growth of the part above-earth. 8. Earthworms and EM decreased the Cd2+ absorption ratio and maximum absorption capacity of soil, EM had more evidently effect. With the increase of Cd2+ concentration added to soil , the effect of earthworms and EM on soil desorption ratio went up gradually on general. And with the augmentation of the amount of Cd2+ absorbed, the amount of desorption increased naturally. Especially, when the amount of Cd2+ absorption was bigger than 500mg.kg-1, the amount of desorption increased significantly. Therefore, the existence of earthworms and EM increased the soil Cd2+ concentration, and it could significantly promote the Cd2+ absorption in the root system and Cd2+ accumulation in fruits, especially, the effects were more pronounced when the Cd2+ concentration was rather high.
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