1 建立稳定的区试点避免因条件差异带来的误差,保证区试的准确性与一致性。区试点的选择更有代表性,要将其放在玉米主产区,尤其是各地玉米主推品种区。2 选好试验地块要选择地势平坦、交通方便、四周向阳无荫蔽、土泥深厚、排灌方便、土壤肥力均匀一致的土块。根据各地具体情况 1 to establish a stable pilot area to avoid the error caused by differences in conditions, to ensure the accuracy and consistency of the district test. The choice of district pilot is more representative, it should be placed in the main producing areas of corn, especially the main varieties of corn across the region. 2 selected test plots to choose flat, easy access, surrounded by the sun without shading, deep soil, irrigation and drainage convenience, uniform soil fertility clods. According to the specific circumstances