纵观国际、国内作物产量的提高不外乎：一是以扩大种植面积为主；二是以提高单产为主；三是在扩大面积的同时提高单产。而提高单位面积产量最关键的是品种，更新品种、选育优良品种是最有效、最直接的农业增产措施。使用优良品种，在相同的自然条件和栽培条件下，一般要比... Looking at the world, the increase in domestic crop output is nothing more than the following: one is to expand the planting area; the other is to increase yields; and the other is to increase yields while expanding the area. The key to improve the yield per unit area is the variety, renewal of varieties, breeding fine varieties is the most effective and most direct measures of agricultural production. Use of fine varieties, under the same natural conditions and cultivation conditions, generally more than ...