Abstract
Six cultivars of soybean were cultivated under various phosphorus (P) application levels, in pots and in fields to clarify the relationship between P accumulation and dry matter production, and that of varietal differences in soybeans. Dry matter production and yield components increased with the increase of P application, especially under P-deficient conditions, and there were varietal differences in dry matter production, yield components, and amount of P accumulation. However, there were significant relationships between dry matter production and P accumulation, and the relationships could be represented by the same regression line regardless of cultivar. There were varietal differences in dry matter production efficiency of accumulated P under a P-deficient condition. These results suggest that either high ability to accumulate P or efficient dry matter production of P is required for stable production under P-deficient conditions. Therefore, selection of cultivars that have high dry matter production efficiency or large root systems, or the development of agricultural management technology that increases the rate of P fertilizer absorption is required for stable production under P-deficient conditions.
