Responses of rhizosphere nitrogen and phosphorus transformations to different acid rain intensities in a hilly red soil tea plantation

摘要: Tea (Camellia sinensis) plantation in hilly red soil region has been long impacted by acid deposition, however its effects on nitrogen (N) and phosphorus (P) transformations rhizosphere soils remain unclear. A 25-year old tea a typical was selected for an situ simulation experiment treated pH 4.5, 3.5, 2.5 control. Rhizosihere bulk were collected the third year from simulated deposition experiment. Soil mineral N, available P contents major enzyme activities analyzed using chemical extraction biochemical methods, N mineralization rates estimated indoor aerobic incubation methods. Our results showed that compared to control, treatments of 3.5 2.5, respectively decreased 7.1%, 42.1% 49.9% NO3(-)-N, 6.4%, 35.9% 40.3% 10.5%, 41.1% 46.9% P, 18.7%, 30.1% 44.7% ammonification rate, 3.6%, 12.7% 38.8% net N-mineralization 31.5%, 41.8% 63.0% rate soils; however, among 4 treatments, nitrification not significantly different, urease phosphatase generally increased with increasing intensity rain (P<0.05). In soil, did cause significant changes as well nitrification, ammonification, mineralization. With intensity, NH4+-N, altered positive negative effects, those phosphatease opposite trends, positive. sum, prolonged elevated could reduce transformation rates, decrease their availability, alter have impact nutrient cycling plantation.