玉米、高粱、谷子是我县主要粮食作物,由于降雨量少且分布不均,单产低而不稳。近几年来,广大农户挖掘水源,实行旱灌,玉米、高粱、谷子亩产分别达到700～1,100斤、800～1,200斤和500～700斤的水平。许多高产农户的实践证明,要获得丰收,必须按作物的需水规律灌水。高粱、玉米和谷子在拔节至抽穗期间,根茎、叶迅速生长,光合作用旺盛,对水分很敏感。如果此阶段缺水,就将抑制根、茎、叶的生长和穗,花分化.而下透雨或及时灌水,可增产16至24％。抽穗至灌浆是作物需水 Maize, sorghum and millet are the main grain crops in our county. Due to the low rainfall and uneven distribution, yields are low and unstable. In recent years, a large number of farmers have tapped water sources and practiced dry irrigation. The output of corn, sorghum and millet reached 700-1,100 kg, 800-1,200 kg and 500-700 kg respectively. The practice of many high-yielding peasants has proved that in order to obtain a good harvest, irrigation must be carried out according to the law of crop water demand. Sorghum, corn and millet in the jointing to heading, the rapid growth of rhizomes, leaves, photosynthesis, moisture sensitive. If this phase of water shortage, it will inhibit the growth of roots, stems and leaves and spike, flower differentiation, while under the rain or timely irrigation, yield 16-24%. Heading to grouting is crop water