Effects of Different Management Practices on Plant Community and Soil Properties in a Restored Grassland

Understanding how the type of land-use affects the relationship between plant communities and soil properties is essential to design suitable grassland management practices. A few studies, however, have explored the trade-off between productivity, species diversity, and soil properties under different management practices in grasslands. We conducted a field experiment to assess the effects of long-term enclosures, enclosure plus nitrogen (N) addition, grazing, and grazing plus N addition on the pattern of biomass allocation in dominant species, community biomass, species richness, and soil properties in a semi-arid grassland on the Loess Plateau of China. Our results indicated that N addition significantly increased the allocation of biomass to leaves in the enclosed grassland but altered the biomass allocation from above-ground to below-ground plant organs in the grazing grassland. Compared to the enclosure plots, a combination of enclosure and N addition significantly increased community biomass, though it detrimentally affected species richness. In contrast, grazing and grazing plus N addition decreased community biomass, but it increased species richness. We also found that soil nitrogen content (TN), soil organic carbon (SOC), and soil phosphorus content (TP) responded differently to all four implemented management practices. A combination of enclosure and N addition significantly increased soil nutrients content, whereas grazing and grazing plus N addition decreased the soil nutrient content. The results from this study showed that a combination of enclosure and N addition can be recommended for improving productivity and soil quality in restored grasslands on the Loess Plateau of China. Taken together, this research provided a theoretical basis for grassland protection and adaptive management.