In order to reveal the physicochemical properties and their influence mechanism of soil in different rocky desertification in karst area

a four-year monitoring was conducted on soil in different rocky desertification degrees (potential

light

moderate

intensity) before

during and after rainy season in rocky desertification area

Bijie

Guizhou. Physicochemical properties and their correlation characteristics of different soils were analyzed. The results were as follows: in the soils with the same rocky desertification degree

the contents of soil organic matter

total phosphorus

available phosphorus

total nitrogen and hydrolysable nitrogen were all in order as: during rainy season＞after rainy season＞before rainy season. With the deterioration of rocky desertification

soil retention ability

capillary retention ability

capillary porosity and total porosity of soil increased

and the contents of total phosphorus

available phosphorus and organic matter in soil decreased. Compared with the soil in potential rocky desertification degree

total nitrogen contents of soils in light rocky desertification

moderate rocky desertification and intensity rocky desertification increased by 5.6%

20.9% and 26.6%

respectively

and hydrolysable nitrogen contents of different soils increased by 3.5%

18.3% and 36.2%

respectively

total potassium contents of different soils increased by 15.8%

30% and 46.3%

respectively

available potassium contents of different soils increased by 3.9%

11.3% and 16.5%

respectively. Correlation analysis suggested that organic matter content

total phosphorus content

total nitrogen content

bulk density

total porosity and capillary retention ability correlated significantly (p ＜0.05)

and organic matter content

total nitrogen content

bulk density and total porosity correlated extreme significantly (p＜0.01). These results can provide theoretical and scientific basis for the comprehensive control of rocky desertification.