无定形铝氧化物添加对酸化土壤有机氮矿化的影响

Effects of Amorphous Aluminum Hydroxide Addition on Soil Organic Nitrogen Mineralization in Acid Phyllostachys praecox Soils

摘要:

通过采集不同种植年限(0、4、18 a)的雷竹林土壤，利用添加无定形铝氧化物的方法进行模拟试验，研究了土壤酸化条件下铝的活化对有机氮矿化的影响。结果表明：无定形铝氧化物的添加会抑制土壤有机氮矿化，且添加量与氮矿化抑制率呈显著线性相关；当添加量为20 g/kg时，0、4、18 a种植年限土壤有机氮矿化抑制率分别为22.42%、31.86% 和35.31%。不同无定形铝氧化物添加量处理时，土壤有机氮矿化后无机氮中铵态氮含量无显著变化，硝态氮含量则显著下降，矿化氮中铵硝比随添加量显著增加，由此说明无定形铝氧化物添加对土壤有机氮矿化抑制主要表现为对硝化过程的抑制。可见，土壤酸化会显著降低土壤氮的矿化，影响土壤养分循环。

Abstract:

In order to understand the effect of active aluminum induced by soil acidification on soil nutrient transformation, the amorphous aluminum hydroxide was applied to Phyllostachys praecox soils in various planting times (0, 4, 18 years) to measure soil organic nitrogen mineralization using an intermittent eluent culture method. The results showed that the addition of amorphous aluminum hydroxide inhibited soil organic nitrogen mineralization, and there was a significant linear correlation between the addition rate and the inhibition rate of nitrogen mineralization. The inhibition rates of soil nitrogen mineralization were 22.42%, 31.86% and 35.3%, respectively, in the three soils with the addition rate of 20 g/kg. Ammonium content showed stable in various treatments but nitrate content decreased significantly with the addition rate of amorphous aluminum hydroxide. The ratio of ammonium to nitrate in mineralized nitrogen increased significantly with the increasing addition rate, suggesting that the inhibition of nitrogen mineralization was mainly resulted from the nitrification inhibition. Overall, soil nitrogen mineralization will decrease under the acidic condition that exert further a great impact on soil nutrient cycling