氯离子对土壤中氮肥的行为及微生物数量和酶活性的影响

Effects of Cl- on transformation of nitrogenous fertilizers,microbes and enzyme activities in soil

在土培条件下,研究了不同Cl^-浓度对氮肥转化、土壤微生物数量及酶活性影响。表明Cl^-对土壤中细菌、放线菌、真菌的总量无明显影响,但能明显减少亚硝酸细菌数量,因而土壤中NO_3^--N形成减少。Cl^-还能提高滨海盐土中磷酸酶和脲酶及潮土中磷酸酶的活性,经显著性检验,达1％显著水平,但在低丘红壤,施Cl^-500～1000mg/kg土的处理,两种酶活性均降低,经显著性检验,达5％显著水平。

The studies on the effect of different Cl- concentration on nitrogenous fertilizer transformation, microbes and enzyme activities under condition of soil culture have obtained main results as follows . ①Cl- inhibited activity of the nitrosifing bacteria remarkably and transformation from NH4+-N to NO3--N,there was significantly negative correlation(r=- 0. 9327)between NHr-N and NO3--N. ②Cl- increased phosphatase activity in shore saline soils and fluvo-aquic soils as well as urease activity in shore saline soils. This was statistically significant at the 1 % level. But in the red soils Cl- applied in 500-1000 mg/kg soil reduced the activities of both phosphatase and urease and this was statistically significant at the 5% level. ③In the experiment Cl- concentration had no effect on the population of bacteria,fungi ,actinomycetes.