Effect of Spacial Coupling Between Irrigation Water and Fertilizer on Corn in Semiarid Area

Field experimentation of different spacial couplings of different amounts of irrigation water and nitrogen fertilizer on corn (Zea mays L.) at the stages of earing and jointing was carried out in Yangling lo cated in a semiarid area. The results indicated that (1) there was little difference between the treatments of alternate irrigation with even fertilizing, alternate irrigation with fertilizing in the irrigated furrow and alternate irrigation with fertilizing in the unirrigated furrow under two amounts of irrrigation water, 1 125 m³/hm² and 600 m³/hm²; (2) the yield decreased less than 15.26% as the amount of irrigation water of the whole growth season decreased from 2 250 m³/hm² to 600 m³/hm²; (3) the physiological indexes, yield and water use efficiency of the treatment of alternate irrigation with fertilizing in the irrigated furrow and alternate irrigation with fertilizing in the unirrigated furrow, were higher than other treatments; (4) more irrigation water resulted in lower water use efficiency. Results of this research suggest that there is great potential to save irrigation water in corn production in Yangling. It was shown that alternate irrigation with fertilizing in the irrigated furrow and alternate irrigation with fertilizing in the unirrigated furrow with an irrigation level of 562.5 m³/hm² is more effective than other methods of coupling.