Changes in Soil Organic Matter, Nitrogen and Phosphorus Contents during Decomposition of Pear Branches

[Objectives] To investigate the changes in soil organic matter, nitrogen and phosphorus content in the decomposition process of Korla fragrant pear branches by indoor mixed culture. [Methods] The branches of Korla fragrant pear in the orchard were collected and returned to the field for a period of 150 d for indoor mixed culture. [Results] Different ages of Korla fragrant pear branches have different effects on soil nutrient content during the simulated return to field decomposition process. Compared with the control in the same period, the treatment of returning to field reached a significant level (P<0.05). Compared with the control, the average values of organic matter, total nitrogen and available phosphorus content in treatment 1 and treatment 2 increased by 2.16 times and 1.93 times, 61% and 59%, 5.88 times and 6.88 times, respectively; compared with the control, the average increase performance of the alkaline hydrolysis nitrogen content of the two treatments was basically the same, and the treatment 2 was the best; compared with the control, the average total phosphorus content of treatment 1 and treatment 2 increased but not significantly. [Conclusions] The contents of soil organic matter, nitrogen and phosphorus were all increased during the decomposition of pear branches, and the overall improvement effect of 10-year-old trees was better than that of 5-year-old trees. Returning the pruned branches to the field can provide a reliable theoretical basis for solving the problem of organic fertilizer shortage in orchards, and als