Evaluation of the phosphorus nutrient characteristics of maize inbred lines at the seedling stage 不同小麦品种(系)吸收利用氮素效率的差异及有关机理研究Ⅱ.影响吸收效率的因素分析 Screening and cluster analysis of nitrogen use efficiency of different wheat cultivars at the seedling stage A study on the physiological properties of root systems in various wheat varieties and the effects of their phosphorus uptake and utilization efficiency on the yields Genotypic variations for nitrogen use efficiency in winter wheat I.Effects of N uptake and utilization efficiency on grain yields Water and Nutrient Use Efficiency in Diploid, Tetraploid and Hexaploid Wheats Effects of delayed irrigation at jointing stage on nitrogen accumulation and its allocation, and NO3-N migration in wheat The mechanism behind genotypic differences for nitrogen use efficiency in crops Nutrient Uptake and Use Efficiency of Diploid, Tetraploid, and Hexaploid Wheats under Different Water and Nutrition Conditions Differences in root architecture of several Stylosanthes genotypes and their phosphorus efficiency Effects of different nitrogen application rates on grain yields and nitrogen uptake and utilization by different rice cultivars Effect of nitrogen fertilization on maize yield and nitrogenefficiency of different maize varieties