Effect Of Soil Surface Electric Field On Nitrification In Acid Soil

Nitrification is widespread in the soil, it is an important process in soil N cycling. Nitrification can change NH4+-N into NO3--N, NO3--N formatted in this process could be utilized by plants more easily, but the process will also lead to the accumulation of NO3--N, NO3--N can infiltrate into the groundwater as the reason of soil leaching, leading to serious pollution of groundwater. How to make effective use of NH4+-N and NO3--N is a hot topic at the present stage.Acid soils constitute a high proportion in China.In southern China,there distributes brick red soil, red soil, yellow soil and other major acid soil. The basic characteristics of acid soils are:high acidity, soil sticky, low fertility, so how to improve the red soil area, N fertilizer utilization factors and how to effectively prevent groundwater pollution has become the focus of nitrification in acidic region.Early studies showed that:in alkaline soils nitrification have a wide range of existing and highly activity but nitrification is almost non-existent in acidic soil. However,much researching provide evidence that nitrification also exist in acidic soil, and in certain acid soils, nitrification and even very strong. For these reasons, acidic soil nitrification take more and more research attention. Many scholars on the impact of acid soils nitrification factors and mechanisms are done in detail.Acid soil is a kind of based-unsaturated soil, thus leading to the acid soil is a variable charge soil. The soil has large surface area, and a large number of variable charges. These charges will inevitably change the nature of the soil, in such condition, soil nitrification would be severely affected. Therefore, in this paper, changes in surface electrochemical properties of the acidic soil how to impact nitrification activity and how much is a focus of this study. Studies on the surface electrochemical properties of soil have been long time, but until now the traditional method is not very accurate responses to the soil surface electrochemical properties of the true, Li Hang (2002) proposed the constant current method to solve this problem, this study provides a theoretical basis to make this research,that can really change the surface properties of the angle of phone to analyze and solve soil nitrification change.This study used a relatively small man-made factors of acid yellow soil in Jinyun Mountain pine (pH=5.2) as the research object, add a different quality than the high purity of Ca-montmorillonite to change the surface electrochemical properties of soil. In order to eliminate the impact of montmorillonite with different pH levels change on nitrification in the soil, stood before the experiment, we adjust samples with different pH to the same as the primary soil. In this study, the determination of electrochemical properties of soil that:electrochemical properties of soil will be changed after joining the montmorillonite, but the content of montmorillonite in the 8% before the change in electrochemical properties of soil is relatively small, but with Mongolia stone removal and further increase in soil surface field, surface potential, surface charge density, the number of surface charge, surface area increased significantly, and there is obviously a change of electrochemical properties, in order to further distinguish between different surface electrochemical properties of the sample laid the foundation, which can change from the perspective of the electrochemical properties of soil nitrification activity characteristics.This experiment also compared the different pH of soil samples (corresponding to adding the mass ratio of montmorillonite were measured after different soil pH), which from the point of view of soil pH changes in the changes in nitrification.The results shows that within both surface electrochemical properties of different samples and different samples of soil pH these all exist nitrification and nitrification intensity is high. The soil nitrification process is not complete and also exists NO2 -N accumulation phenomenon. During soil cultivation process, due to microbial effects which can produce acid, pH declined continuously. Soil surface electric field has no effect on pH, but with soil pH decreasing during cultivation, the pH of different soil samples drop with different range. The surface properties of different phone nitrification study shows that:With the increased electrochemical properties of the soil surface, soil NH4+-N accumulation decreased, NO3--N and NO2--N content was significantly increased, the soil net nitrification rates coincided with a significant change in the nature of the soil surface telephony soil samples with high rates of soil net nitrification was significantly higher. Samples of different pH on nitrification activity results show that:soil pH on soil nitrification and different surface electric field effects on nitrification different.In summary,changing soil surface electrochemical properties can lead soil nitrification significant change. It needs further studies on the mechanism of electrochemical properties effection on soil nitrification activity.