关键词: 旱作冬小麦, 黄土旱塬, 增产潜力

Abstract: The grain yield of dryland crops had been increased extensively on loess tableland after adopting new agricultural technologies which were introduced during the Seventh and Eighth Five Year Plan periods.But during the Ninth Five Year Plan,the grain yield still fluctuated around the previous level.So both government and farmers are very concerned about the potential yield increase,especially yield of winter wheat,and how to do.Based on data obtained from long term yield potential and fertility experiments in situ,the model for calculating sunlight temperature water fertility yield of dryland winter wheat was established,and the potential yield increase was also analyzed from four yield levels.They are sunlight temperature yield productivity,sunlight temperature water yield potential,sunlight temperature water fertility yield and the present yield on experimental plot.The results indicated that the present yield of winter wheat on loess tableland region only reached 41.6% of the sunlight temperature yield productivity,49 3% of the sunlight temperature water yield potential and 78.6% of the sunlight temperature water fertility yield.At last we believe that the yield of winter wheat on loess tableland region can continuously increase and reach a new higher level by means of reasonably increasing soil fertility and better field management.

Key words: dryland winter wheat, loess tableland, potential yield increase