马尿酸在土壤中的分解及对土壤酶活性的影响

Decomposition Characteristic of Hippuric Acid and Its Impacts on Soil Enzymatic Activity

选用沈阳市东陵区天柱山耕作棕壤,采用室内培养试验,研究了外源马尿酸在土壤中的分解特点及其对土壤酶活性的影响。结果表明:不同浓度外源马尿酸在土壤中的分解均呈现出分解速率较快的特点,于第7d降解率可达98%以上,其分解速率可用动力学模型进行描述。马尿酸对土壤酶的影响主要表现在培养的7～42d;其中,对中性磷酸酶、脲酶、转化酶活性的影响均表现为中、高浓度显著抑制,低浓度显著促进,且浓度间差异显著;对土壤过氧化氢酶活性的影响,各浓度均表现为显著的抑制作用,随浓度增加抑制增强,不同浓度间差异均达显著水平。与马尿酸在土壤中的分解特点相比,马尿酸对各酶的影响显示出了滞后性,进而对养分转化的影响会有较长期性。

As hippuric acid existed extensively in manure,therefore,its agricultural influence has been considered as an important topic to be studied.In this study,we collected cultivated brown soil from Tian Zhu Mountain in Shenyang East Mausoleum.The decomposition characteristic of hippuric acid and the effect of hippuric acid on soil enzyme activity were studied in the laboratory.The results showed that the contents of all exotic hippuric acid firstly decreased rapidly,then decreased gradually lower than initial value.The hippuric acid＇s changing speed and range of different concentration were different at different incubation stages.The regression equations had significant correlation between hippuric acid decomposting rate and time.The results showed that the decomposition rate of hippuric acid was 98% at the seventh day.From the 7th to 42th day of incuabtion,the hippuric acid influenced the activity of the soil enzyme significantly.The effect of hippuric acid on the soil neutral phosphatase,soil invetase and urease activities was activation at low concentration and inhibition at high concentration,then remained at a stable level.And the effect on soil catalase activity was inhibition at each concentration,which being strengthened as its contents increased.Compared with the decomposition characteristic of hippuric acid in the soil,the effect of hippuric acid on the soil enzyme delayed,so it would influence trophic transformation in longer time.