Difference In The Activity Of Nitrification And Denitrification With Different Soil Acidity

Soil pH is an important factor influence the activity of soil nitrification and denitrification activity. Different regions and fertilizer systems have different effects on black soil acidity. Soil acidity influenced the nitrogen transformation and the activity of soil microorganisms. In this paper, black soil samples which were collected from different regions and different acidity and which were collected from same region and different acidity were used as the research object. The first series contained eighteen black soil, which were collected from Gongzhuling city, Jilin province and Yushu city, Jilin province. The sencond series contained fourteen black soil, which were collected from the Key Observation Station of the Harbin Black Soil Ecology of Harbin city, Heilongjiang province. Suspension culture method was used to determine soil nitrification potential, anaerobic sludge culture method was used to determine soil denitrification potential, and real-time quantitative PCR was conducted to investigate the abundance of nirK, nirS and nosZ gene in denitrifying bacteria. The results of the study were as follows:Study on soil nitrification potential and denitrification potential of different regions and different acidity showed that different regions had different soil acidity which affected soil nitrification potential and denitrification potential. To the soil nitrification potential of Gongzhuling city, Jilin province and Yushu city, Jilin province, the results indicated that the nitrification potential in soil was the highest when soil pH ranging from8.10to8.30; nitrification potential in soil was the lowest when soil pH ranging from5.80to6.20. When the soil pH was acidic or alkaline, the soil pH had significantly effect on soil nitrification potential; when the soil pH was neutral, the soil pH had no significant effect on soil nitrification potential. To the soil denitrification potential of Gongzhuling city, Jilin province and Yushu city, Jilin province, the results indicated that denitrification potential was not significantly related to the soil pH.Study on soil nitrification potential and denitrification potential of same region and different acidity showed that different fertilizer treatments had different effects on soil acidity, and then influenced soil nitrification potential and denitrification potential. To the soil of the same region and different fertilizer treatments, in a certain range of pH, soil nitrification potential and soil denitrification potential were increased with the increase of soil pH.Study on soil denitrifying microorganisms of same region and different acidity showed that the soil pH had different effects on the abundance of nirK, nirS and nosZ genes in denitrifying bacteria. In a certain range of pH, the abundance of nirK and nirS gene in denitrifying microorganisms were significantly related to soil pH. But the abundance of nosZ gene did not show correlation. The abundance of nirS genes in denitrifying bacteria were related to soil denitrification potential.