Impact of different land uses on potassium forms and soil properties: the case of southwestern Iran

The primary focus of this research was to evaluate the influence of various land utilization patterns on the potassium levels and fertility attributes of the soil in Kohgiluyeh and Boyer Ahmad Province, located in the southwest region of Iran. This prioritization is essential due to the rising population and the need to meet the food requirements of the people. Hence, this study used the release of potassium (K) by using CaCl2 and oxalic acid 0.01 M as extractants. Additionally, the study measured the capacity of K fixation in calcareous soils under different land-use systems, specifically wheat, garden, forest, fallow fields, and pastures. The K release and fixation capacities were assessed in both surface and subsurface soil layers using alternative wet, dry, and normal treatment methods. The results revealed that the median soil pH across the studied land uses was 7.4, ranging from 6.5 to 7.7. The highest pH was observed in the wheat land use, while the garden land use had the lowest pH. In terms of organic carbon content, the studied soils exhibited variations ranging from 0.9 to 1.94%. These differences can be attributed to variances in mineral structures among different soil types. To mitigate the loss of fertilizer sources and prevent groundwater contamination, it is recommended to implement a combination of commercial fertilizers with targeted micronutrients. Additionally, adopting soil conservation techniques and encouraging long-term fallow practices can also contribute to these efforts. In conclusion, the findings emphasize the importance of implementing appropriate soil management strategies to enhance nutrient availability, minimize environmental risks, and sustain agricultural productivity.