Abstract
The long-term growth of pure forest is an important issue that affects stability and sustainable development of ecosystem, while using forage litter as fertilizer or directly establishing tree-grass complex vegetation may be the most effective prevention way. This study took the artificial pure forests of Betula platyphylla, which were widely distributed in the Loess Plateau of China, as the object and conducted a 120-day decomposition incubation experiment of forest humus soil mixed with seven common leguminous forage litters to study the effects of forage litters in controlling the degradation of soil biological and chemical properties of pure forests. The results showed that: by adding forage litter to the soil of pure B. platyphylla forest, litters of Lespedeza bicolor and Onobrychis viciaefolia improved the soil quality obviously, followed by Astragalus adsurgens and Melilotus officinalis, while Medicago sativa lead to obvious deterioration, followed by Vicia villosa and Coronilla varia.