Abstract:
Objective The paper aimed to explore the soil quality assessment and its spatial distribution of five conventional soil indicators in Fujian Province, so as to provide scientific basis for protecting and improving the cultivated soil quality according to local conditions.
Method In the present study, five conventional indicators, including soil pH, soil organic matter (SOM), hydrolysable nitrogen (Avail-N), available phosphorus (Avail-P) and available potassium (Avail-K) from 4756 groups of cultivated soil in Fujian Province measured in 2019, the soil quality index (SQI) method and GIS technology were applied to assess the soil quality and mapping the spatial distribution.
Result The average values of the five conventional soil indicators in Fujian Province were pH 5.48, SOM 23.01 g kg−1, Avail-N 146.69 mg kg−1, Avail-P 74.00 mg kg−1, and Avail-K 145.74 mg kg−1, respectively. The results have showed a serious soil acidification, abundant Avail-P and -K, and moderate SOM and Avail-N. Also, the soil pH, Avail-P and -K in ‘Southeast Fujian’ region were higher than those in ‘Northwest Fujian’ region, and the SOM and Avail-N in ‘Northwest Fujian’ were higher than those in ‘Southeast Fujian’. The results of soil quality evaluation showed that the average value of SQI in Fujian Province was 0.637, in which Xiamen had the highest SQI (0.671), and Quanzhou had the lowest SQI (0.558). Moreover, the contribution of Avail-P in SQI was the largest (26.20%), the pH value was the smallest (11.07%), and SQI was significantly positive correlated with all soil indicators. As a whole, the spatial distribution of SQI in Fujian Province shown a changing trend that the region of ‘Northwest Fujian’ was higher than that of ‘Southeast Fujian’.
Conclusion The cultivated soil quality of Fujian Province is mainly at a medium and high level, and the serious soil acidification and excessive Avail-P content were the key limiting factors. It suggested that the strategies of soil acidification improvement and phosphorus fertilizer reduction were mainly concerned for cultivated soil quality improvement and agricultural green development in Fujian Province.