生草减肥措施对坡地芒果园氮磷流失及养分吸收的影响.

[ Objective]The effects of biological coverage with fertilizer reduction on nitrogen( N) and phosphorus( P) loss and nutrient absorption in slope mango orchards were explored to provide a scientific basis for effective prevention and control of N and P loss and nutrient increase in slope mango orchards. [Method] The experiment was conducted in a Rerong five-year mango orchard in Baise, Guangxi with two treatments of biological coverage with fertilizer reduction and conventional management. The runoff, sediment load, N and P load of slope mango orchard under two treatments and natural rainfall were measured. Meanwhile, the absorption of N,P and potassium( K) of mango were also analyzed. [Result] The rainfall in the study area was mainly from May to August, and the moderate rainfall or above accounted for 77. 28 % of the total rainfall in the observation period. Runoff occurred in continuous heavy rainfall or single rainfall greater than 30 mm. There was extremely significant positive correlation between rainfall and sediment, N and P load ( P < 0. 01 ) . Continuous heavy rainfall was the main source of sediment and N and P load, where the amount of sediment and N and P load accounted for 74. 23 % - 85. 74%, 73. 70% -83. 06% and 77. 88% -85.18% of the total sediment and N and P load,respectively. The total runoff,mean sediment content,and total sediment,total N and total P load under biological coverage with fertilizer reduction treatment were 476. 2 m3/hm2,1. 35 g/L,688. 8 kg/ hm2,1014. 7 g/hm2 and 74.9 g/hm2,respectively,which were 66.20%,66.42%,88.68%,79.39% and 83.51% lower than those under conventional management treatment respectively compared with conventional management treatment. At the same time, the partial productivity and N, P and K absorption under biological coverage with fertilizer reduction treatment were 19. 3 kg/kg, 108. 9 g/ plant, 16. 4 g/ plant, 151. 8 g/plant respectively, which were 29. 31 %,8. 68%,9. 33% and 8. 98% higher than those under conventional management treatment respectively. [ Conclusion] In the slope mango orchard in the mango production area of Baise, Guangxi, surface runoff occurrs during continuous heavy rainfall or single rainfall greater than 30. 00 mm,and is extremely significantly positively correlated with precipitation. The runoff,sediment, and N and P load are more significantly affected by continuous heavy rainfall. Compared with conventional management treatment, the application of biological coverage with fertilizer reduction can effectively reduce surface runoff, and sediment, N and P load, also improve partial productivity and N, P and K absorption [ABSTRACT FROM AUTHOR]