This paper is the result of Agricultural geological survey engineering.
Objective Potassium is one of the three essential nutrients for plants and an important factor influencing soil fertility. Distribution characteristics of potassium in topsoil of cultivated land in Tongzi County was carried out to provide environmental geological background reference for county agricultural development and ecological environment evaluation.
Methods Taking Tongzi County as the research area, this paper systematically discussed the content, spatial distribution, grade status and influencing factors of potassium and available potassium in surface soil samples obtained from cultivated land quality geochemical survey.
Results The content of potassium in topsoil of cultivated land in the study area ranged from 2.50 to 49.60 g/kg, with an average of 20.30 g/kg, and the overall potassium content is mainly in medium, relatively rich and rich grade. The content of available potassium ranging from 22.40 to 684.00 mg/kg, with an average of 112.66 mg/kg, and the content of available potassium was in moderate to relatively deficient grade. Potassium and cation exchange capacity are positively correlated with available potassium, while the pH is negatively correlated with available potassium in topsoil of cultivated land.
Conclusions The distribution of potassium and available potassium in topsoil of cultivated land in the study area is uneven. The geological factor plays an essential role in the content of potassium in topsoil of cultivated land, and the distribution of high−value and low−value of potassium is well integrated with the stratigraphic and tectonics of the study area. The content of potassium in topsoil of cultivated land is mainly controlled by the parent rock, which is relatively low in the limestone and forming soil. Large−scale potassium depletion in the southern part of the study area is related to the widely distributed of the Permian Maokou Formation limestone.
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