近年来,免耕麦中后期早衰的现象日益明显。发生早衰的原因是:①施肥不足,而且有机肥和化肥(多为碳酸氢铵)一般集中施在土表或播种层内,易造成肥分流失。而且后期根系下扎后,下层肥力缺乏,表层肥力利用又和对减少.②土壤肥力和质地不「魂,发生旱衰现象不同.据调查,土壤有机质含量在1.5肠以下时,易发生早衰。③肥料运筹不适宜,拔节孕麟巴所占比重小,而日.多数是在拔节时一次性施入,用的肥料又多是碳酸氢按 In recent years, no-tillage wheat in the late premature aging phenomenon is increasingly evident. Premature senility occurs because: ① inadequate fertilization, and organic fertilizer and fertilizer (mostly ammonium bicarbonate) are generally concentrated in the soil surface or sowing layer, easy to cause fat loss. Moreover, after the root system was tied in the late stage, the lower fertility was deficient, and the utilization of surface fertility was reduced again. (2) The soil fertility and texture were not the same, and the phenomena of drought and decline occurred differently. Â ’¢ fertilizer operation is not appropriate, the proportion of lymph nodes in the joint pregnancy is small, and most of the time in the jointing one-time application, with more fertilizer is bicarbonate