1试验地的选择试验地的选择首先应考虑能代表当地的自然条件和生产条件,试验选出的优良品种才能大面积推广应用并发挥较大的增产作用。试验地块要平坦,排灌方便,肥力在中上等且均匀,前茬作物品种相同。地块平坦是为了田间管理方便,中上等肥力是为了保证试验有较好的 A choice of test sites The choice of test sites should first consider the local natural conditions and production conditions should be considered to test the selection of good varieties in a large area to promote the use of large-scale production and play a role. Test plots should be flat, convenient irrigation and drainage, fertility in the first-class and uniform, the same crop varieties before the crop. The plot is flat for field management convenience, the best fertility is to ensure that the test is better