The Composition And Surface Chemical Properties Of Several Kinds Of Zonal Soil In Hubei Province

Subtropical areas in China have the characteristics of high rainfall, temperature, and high degree of soil weathering, leaching and so on. Different types and graded soils can not only reflect the zonal of climate changes, but also have a big impact on the remain, release of nutrient elements and heavy metals in soil. In this research, we had collected red soils, yellow brown soils and brown soils from Yang xin, Tong cheng, Xiang yang in Hubei province, respectively from south to north in subtropical region of our country. Analyzing the basic physical and chemical properties of this soils, and studied the surface chemical properties of brown soil, red soil from Xiang yang(XY) and Yang xin(YX) soil with different size(colloid, 450-2000 nm, 100-450 nm), and also with/without organic matters, including soil specific surface, Zeta potential, conductivity, etc. And then the absorption, desorption of elements copper and phosphorus, the results showed that:(1) With the increased of latitude, the value of p H of this soils showed the trend of rising, and different form of total iron and aluminum oxide showed the trend of decrease; compared with the leaching layer, the p H of the deposition layer had the trend of decrease first, and then rising, and the higher the latitude, the greater the amplitude of rising; compared to the eluvial horizon the soil organic matter, total N content decreased in the deposition layer and soil parent material layer, and the higher the latitude, the greater the amplitude of decreased. With the increased of the level, the soil cation exchange capacity increased in different degrees; the clay content increased in the deposition, parent material layer; and the different forms of iron and aluminum oxide content gradually reduced.(2) The removed of organic matter, had a great effect on soil chemical properties, such as soil the particle size obviously decreased of the Xiang yang brown spots after the removed of organic matter; the soil p H got lower; the conductivity and specific surface showed a significant raised; Soil Zeta potential value tend to became bigger. Compared with different particle size of soil can be seen that as the particle size from 450-2000 nm to 100-450 nm, the soil electrical conductivity, p H value and specific surface all showed a trend of increased. Different graded soil specific surface had the order of 100-450 nm > colloid > 450-2000 nm particles.(3) By the resulted of copper adsorption in different type of soil particles, we can seen that: the copper adsorption quantity was more in soils that with high organic matter content, did not removed organic matter and the soils with smaller particle sizes. Compared the adsorption performance of copper in the soils of Red and brown spots with different particles on, we could see that Xiang yang browns soil that with organic matters had the biggest adsorption quantity, next to the browns soil which had been removed the organic matters, then was the red soil of Yang xin; the adsorption quantity of different soil sizes were the 100-450 nm size were greater than the 450-2000 nm and colloid particles. From the desorption rate data we could see that the desorption of copper in clay mineral was very easy after the adsorption, and the lower organic matter content, and the smaller particle sizes conduct to the bigger desorption rate, we could see from that the Xiang yang browns’ desorption rate was greater than the red soil of Yang xin; the soils which had been removed organic matters showed the bigger desorption rate than that had not removed organic matters; the 100-450 nm particles desorption rate was bigger than other large fraction particles, the 450-2000 nm particles and colloid had similar and also smaller desorption rate of copper.(4) The adsorption quantity of phosphorus in both soil were little, the phosphorus adsorption quantity was more in soil that had not been removed organic matters, and the browns soil had more adsorption quantity than the red soil, the most adsorption quantity of different soil sizes was the 100-450 nm size, then was the colloid particles, at last was the 450-2000 nm. The desorption rate of phosphorus in different types, different graded soil were all small, range from 5-18%.