Abstract
Summer cover crops are one of the most effective ways to improve the soil quality and agricultural environment because they offer many benefits to the agro-ecosystem, such as addition of organic matter, accumulation of nutrients, and contribution of nutrients to subsequent crops. However, the benefits are often not taken into account in farming systems because they are complex and differ depending on cover crop species and management. This research evaluated the growth of summer cover crops and their function for the agro-ecosystem based on multivariate analysis. The main results were as follows.
1) The accumulation of cover crop dry matter was significantly higher in oat and white mustard in June, but was the highest in sorghum in August.
2) The accumulation of cover crop nutrients increased as the accumulation of dry matter increased.
3) The yield of broccoli following summer cover crops was the highest after crotalaria and the lowest after mixed flowers.
4) Based on principle component analyses, summer cover crops were evaluated at each growth termination. These results suggested that the classification of summer cover crops were divided by their biomass accumulation and CN ratio.
5) Our results suggest which there is an appropriate selection of summer cover crops to establish a new farming system that maximizes the benefit of cover crops for agro-ecosystems.
