The low-phosphorus efficiency soybean genotypes, D03, D05, D17 and D18, and the high-phosphorus efficiency soybean genotypes, D31, D34, D37 and D38 were selected. The soil culture experiment was conducted. There were 2 treat- ments, high phosphorus （＋P） and low phosphorus （-P）. The difference in absorption of N, P and K among different-phosphorus efficiency soybean genotypes at the seedling stage was analyzed. The results showed in the low phosphorus （-P） treat- ment, the P absorption amount differed among roots, stems and leaves of different high-phosphorus efficiency genotypes. The P absorption amount was positively relat- ed （P〈0.05, P〈0.01） to the dry weights of root, stem and leaves, but was negative- ly related to the utilization efficiency of phosphorus （P〉0.05）. The N and K absorp- tion amounts of root, stem and leaves all trended to decrease. The low phosphorus stress would inhibit the absorption of N, P and K in soybean plants at the seedling stage. However, the adaptability of the high-phosphorus efficiency soybean geno- types to low phosphorus stress was significantly higher than that of low-phosphorus efficiency genotypes.
[Objective] Simple and reliable identification criteria used in screening phosphorus efficiency of soybean at seedling stage was discussed.[Method] Using the high and low phosphorus soil pot experiment,the soybean seedling stage＇s 5 criteria including RPH,RAW,RRW,RAPC and RRPC were studied.[Result] Low phosphorus stress had the low effects on relative plant height,the coefficient of variation was only 9.07%,has not achieved the remarkable level with its its criteria＇s relevance;Low phosphorus stress had the higher effects on relatively above-ground dry weight and relative dry weight of root,relatively above-ground phosphorus concentration and relative root phosphorus concentration,its coefficient of variation was also big,in turn is 26.67%,22.68%,24.01% and 15.87%,The correlation coefficient among the indicators had significantly or extremely significantly positive correlation.[Conclusion] Relatively above-ground dry weight and relative dry weight of root,relatively above-ground phosphorus concentration can be used as an important indicator of comprehensive evaluation of screening phosphorus efficiency of soybean at seedling stage,while the relative root phosphorus concentration can be used as secondary screening index.
