关键词: 酶学性质, 酶学性质

Abstract: The purpose of this paper was to study the effects of atmospheric nitrogen wet deposition on tobacco produced. Growing attention has been paid on atmospheric nitrogen (N) deposition in China for its rapid increase because of the sharply increasing emissions of nitrogenous pollutants in the last two decades. However, quantification of atmospheric N deposition in tobacco planting areas, which is related to acidification and eutrophication as well as the tobacco quality, is still rare. In this study, monitoring of N wet deposition at five sites in Fujian tobacco planting area was carried out in 2009. The annual precipitation ranged from 1134 mm to 1737 mm. Concentrations of total nitrogen (TDN), NO3--N, NH4+-N and dissolved organic nitrogen (DON) were 1.14 mg/L, 0.37 mg/L, 0.39 mg/L and 0.38 mg/L, respectively. The total N wet deposition ranged from 11.77 kg/(hm2?a) to 20 kg/(hm2?a), with an average value of 15.94 kg/(hm2?a). Both the concentrations and deposition decreased from the north to the south along the Wuyi Mountain. Higher N concentrations were found in January, February, September and October at all the five monitoring sites. Except Changting site, large parts of N deposition were concentrated on the warm season, from March to September. During the tobacco planting season (February to July), inorganic N deposition (DIN), DON and TN deposition accounted for 44%-62%, 33%-67%, and 44%-63% of that for the annual deposition, respectively. N deposition increased with the precipitation at all monitoring sites, fitting a power equation (r2=0.41).