In a certain year, in the same planting condition, bottomland can save more water, and used up less, which is another reason for highest yield in bottomland.

• 在降水一定的年份，同样的栽培条件下，滩地的储水量大，耗水量小，玉米和莜麦在滩地的水分利用率均高于沙地，这也是两种作物滩地产量高于沙地产量的原因。