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一、华北平原灌溉冬小麦区(包括山东省和天津市的全部,河北省中南部,北京市中南部,河南省中北部,陕西省关中平原,山西省南部)1、施肥存在的问题(1)氮肥过量施用,氮、磷、钾养分比例不平衡。(2)基肥氮用量偏高,一次性施肥面积较大,后期氮肥供应不足;农民春季追肥早、用量大。(3)硫、锌、硼等中微量元素缺乏。(4)土壤耕层浅、保水保肥能力差等问题。2、施肥管理原则(1)根据苗情长势,分次施用氮肥,适当增加拔节中后期施用比例;根据底(基)肥施用量、苗情、温度以及土壤肥力状况科学确定追肥用量和时间;因地、因苗、因时追肥。
I. Irrigation winter wheat area in North China Plain (including all of Shandong Province and Tianjin Municipality, central south of Hebei Province, central south of Beijing Municipality, central north of Henan Province, Guanzhong Plain of Shaanxi Province, southern Shanxi Province) (1) Problems of fertilization (1) Over-application of nitrogen fertilizer, nitrogen, phosphorus and potassium nutrient imbalance. (2) The amount of basal nitrogen was high, the one-time fertilization area was larger, and the supply of nitrogen fertilizer was insufficient in the later period. (3) Sulfur, zinc, boron and other trace elements in the lack of. (4) shallow soil tillage, poor water retention and fertilizer and other issues. Fertilizer management principles (1) According to the growing condition of seedlings, applying nitrogen fertilizer in different stages, increasing the proportion of middle and late jointing stages appropriately; determining the amount and time of topdressing fertilizer according to the application rate of bottom (base) fertilizer, seedling temperature and soil fertility; Due to ground, because of seedlings, due to top dressing.