Successional changes in soil stoichiometry after land abandonment in Loess Plateau, China

Soil nutrient stoichiometry plays a substantial role in terrestrial carbon and nutrient cycling, but how it changes with time since land abandonment remains poorly unclear. By using a chronosequence since land abandonment (0, 5, 10, 15, 20 and 25 years, respectively) in Loess Plateau, China, here, we studied the successional changes in soil nitrogen (N), phosphorus (P), potassium (K) and their stoichiometric ratios. Along this chronosequence, soil organic matter, total and available N increased over time and were highest at 20-year-old age. However, soil P generally decreased with time since land abandonment. Consequently, the ratios of soil N:P increased but P:K decreased following abandonment, indicating that plant growth in this region were limited more by P than by N over time. Our results suggest that soil nutrient stoichiometry is actually impacted by land abandonment in Loess Plateau and such an adjustment of nutrient stoichiometry over time could lead to potential changes in species composition and nutrient cycles in this region.