Study On Soil Nutrient Status And Nutrient Release During The Litter Decomposition In Fuji Apple Orchard At Early Summer In Weibei Highland

After analyzed the physical and chemical characteristics of the soil and content of nutrient elements in decomposing leaves in Fuji Apple Orchard in Fufeng county, Baoji city, Shaanxi province, and the discussion of the soil's physical characteristic and nutrient status at early summer and the releasing rule in decomposing leaves in Fuji Apple Orchard, we got the results as following:1. The contents of soil organic matter in high-yield orchard basically satisfied the demand of high yield and quality apple orchard, but the contents in low-yield orchard were in middle or inadequate level, most of them couldn't satisfy the requirement. The contents of soil available nitrogen, phosphorus, and potassium in high-yield orchard were significantly higher compared with low-yield orchard, the significant diversity was found among different soil layers. Furthermore, the contents of soil available calcium, magnesium and zincum in high-yield orchard were significantly higher than those in low-yield orchard. The contents of soil available calcium in high-yield orchard were accordant with their standards in high-yield and good-quality apple orchard, but the contents in low-yield orchard were in scarce level. The contents of soil available magnesium in sampling orchards were seriously scarce, whereas, the contents of soil available zincum were rich.2. Significant correlations were found between organic matter, available nitrogen, phosphorus, potassium, magnesium and zincum. The correlations of available nitrogen, phosphorus, and potassium were best marked. According to the nutrients requirement of high yield and quality apple orchard, the high-yield orchards should give priority to potassium fertilizer, mixed with some nitrogen, phosphorus fertilizers, the low-yield orchards should increase supply organic,. microelements fertilization.3. Three nutrient elements of N, P, K in apple leaves obviously varied before fallen, but they were diversified; Ca was accumulated because of the stabilization. The amount of K declined in leaves during the 12 months'decomposition, proportion of N and Ca obviously increased, the Mg content changed slightly. Their lost rate was in the order of K > P > N and K > Mg > Ca, respectively.