Objectives

Different recovery methods, (1) Return farmland to wetland (RFW), (2) Return Farmland to Forest (RFF) areas are located in QiXing River Wetland National Natural Reserves. The purpose of this study was to analyze the impacts of different wetland restoration on the soil elements.

Methods

From three regions that RFW, RFF, and NW (Natural Wetland for reference) in QiXing river wetland, the soil samples were collected for soil SOC, TN, TP, NO₃⁻-N, NH₄⁺-N, and SAP contents determination. C:N:P ratios were calculated in the spring, summer, and autumn of 2018.

Results

In this study, soil SOC, TN contents reached Ⅰ standard of China, TP was in medium above to excellent, the soil C:N:P ratios of RFW, RFF, and NW were 138:7.8:1, 131:5.4:1, 145:7.6:1 (molar ratios, the same is as follows), in QiXing river wetland, closed to on China’s soils. And the SOC, TN, NO₃⁻-N, and C:N:P ratios of RFW higher than of RFF, and C:N of RFF more than RFW, indicating that soil SOC were rich in QiXing river wetland, the RFF was more beneficial to available phosphorus release and by N restriction. As elements of plant growth that NH₄⁺-N, TP shown as spring and summer were inferior to autumn, owing to demand of elements in the flourishing period more than in the mature period.

Conclusions

The C:N:P ratios of RFW higher than of RFF, indicating that soil SOC were rich in QiXing river wetland, the RFF was more beneficial to available phosphorus release and by N restriction. While RFW was more beneficial to promotes plants growth and restoration, and soil carbon and nitrogen metabolism and balance.