Abstract: 【Objective】A pot experiment was conducted to find out the nutrient uptakes of nitrogen (N), phosphorus (P), potassium (K) of super-high yielding soybean cultivars and their difference with a common cultivar. 【Method】In 2011 and 2012, two super-high yielding cvs. Liaodou 14, Zhonghuang 35 and one common cv. Liaodou 11 were used in the pot experiment to investigate the effects of different diammonium phosphate (DAP) application levels on soybean N, P, K accumulation and distribution. The experiment was laid out in a complete randomized experiment design with three replications. Diammonium phosphate (DAP) was applied at soybean seedling stage. The treatments consisted of two cultivers and five levels of DAP (0, 50, 100, 150 and 200 mg per kg dry soil). Three pots were selected at random at the stages of V3, R2, R6, R7 and R8. Grains, soybean-roots, and aboveground vegetative samples were collected from all the treatments. The plant samples were dried in the oven at 105℃ for 30 min and 80℃ at least for 72 h to achieve constant weight. The plant samples were weighed, ground and digested with H2SO4-H2O2 acid mixture method. Nitrogen content was estimated by Kjeldahl (KN520) method. Phosphorus and potassium were respectively determined by ammonium molybdate colorimetric assay (UV-2450) and flame photometer (PEAA800). N, P, K accumulation was calculated by multipling dry mass with N, P, K percentage content. The nutrient harvest index was calculated by dividing the accumulative nutrient amounts of grains with total nutrient amounts produced by the plants. Required nutrients of producing weight grain per se were calculated by the accumulation of nutrients and grain yield.【Result】The absorption, transportation and distribution of N, P, K varied with different cultivars and DAP application levels. Super-high yielding cultivars needed to accumulate more nutrients. Their N and P accumulations were significantly higher than common cultivar in addition to seedling. K accumulation of roots was significantly higher than common cultivar in medium pod filling. Super high-yielding cultivars had a stronger capacity of nutrient transportation. Their harvest indexs of N, P and K were significantly higher than common cultivar. However, less nutrients for super cultivars were required to produce weight grain per se. Super-high yielding cultivars had a higher nutrient use efficiency. The application of DAP significantly increased the uptake of nutrients. The results showed that the accumulative amounts and harvest index of N, P, K showed an increasing tendency with the increment of DAP application levels, so as the required nutrient amounts of producing weight grain per se. Among them, the amounts of N and P accumulation, K harvest index and required N and P amounts of producing weight grain per se were maximized by the application of 200 mg•kg-1 of both super-high yielding cultivars and common cultivar. The required N and P amounts of producing weight grain per se of super-high yielding soybean cvs. Liaodou 14, and Zhonghuang 35 increased less than that of common soybean cv. Liaodou 11. The accumulative amounts of K, N and P harvest index, K requirement of producing weight grain per se decreased as the DAP application level was above 150 mg•kg-1. Super-high yielding soybean cvs. Liaodou 14, Zhonghuang 35 decreased less than that of common soybean cv. Liaodou 11. 【Conclusion】Super-high yielding cultivars had a stronger capacity of nutrient absorption and higher transferring efficiency of nutrients. Fertilization significantly enhanced the capacity of N, P, K absorption and transportation, but it reduced the efficiency of nutrient utilization.

Key words: super-high yield , soybean (Glycine max) , N , P , K , absorption