Groundcovers are widely used to improve the sustainability in agriculture production systems. However, the application of groundcovers in intensive short rotation tree plantations is relative new and need to be further investigated. This study aims to (1) investigate the effects of groundcovers and management practices on tree morphology, foliar macronutrients (N, P, K, Mg, and Ca) concentration and (2) on soil fertility and soil macronutrients; (3) evaluate the effects of legume groundcovers combined with low nitrogen fertilization on tree productivity, soil fertility, and nutrient. Three groundcover types including two legumes: alfalfa (Medicago sativa) and Dutch white clover (Trifolium repens) and one grass perennial rye (Lolium perenne) were used in combination with two management practices [banding (B) and no-banding (noB)] and bare-ground (BG) control treatment. Additional studies combining the two legumes and reduced rates of inorganic fertilizer (75%, 50%, and 25% of the recommended rate) was also conducted. Parameters measured include tree height and diameter growth, foliar macronutrients concentration, soil organic matter (SOM) content, soil bulk density, soil nutrients concentration, nitrate leaching and N mineralization rate. Results showed groundcover type selection was not critical for tree growth, and banding practice can help to avoid suppression on tree growth. Groundcover treatments result in lower foliar Ca; can help maintain foliar N levels while receive lower N fertilization; the effect of cover crops on foliar Mg, K and P was not clear. No significant increase in SOM was detected in groundcovers treatment. The lower C:N of legumes did not lead to significant greater N mineralization rates. Receiving reduced fertilization rates, groundcover can still increase soil N and tree growth, decrease soil N leaching. In conclusion, we suggest legume cover crop with high biomass production and low C:N can be introduce into short rotation tree production systems while appropriate management practices are applied.
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