西北绿洲灌区饲用燕麦耗水特性及产量变化对水氮耦合的响应

Water consumption characteristics and yields of fodder oat under different irrigation and nitrogen fertilization regimes in the northwest oasis irrigation area

灌水和施肥是调控作物生长和产量形成的两大重要技术措施,研究水氮互作对燕麦耗水特性及产量的影响,对于优化燕麦高产高效栽培理论和技术具有重要意义。2014-2015年连续两个生长季,在甘肃河西绿洲灌区,田间试验设置3个定额灌溉和3个施氮(纯N)水平,研究水氮耦合对陇燕3号农田0~150cm土层耗水量、棵间蒸发、产量及水分利用效率的影响。3个灌溉处理的灌水量分别为270.0mm(I1)、337.5mm(I2)和405.0mm(I3),3个施N水平分别为90kg/hm^2(N1)、120kg/hm^2(N2)和150kg/hm^2(N3)。在全生育期内,棵间蒸发量(E)及E/ET(总蒸散量)的比例表现先降后升趋势,且相同施氮量下,拔节至灌浆期随灌水量的增大而增大,而灌浆至成熟期则随灌水量的增大而减小。相同施氮量下,燕麦耗水量与籽粒产量随着灌水量的增加而显著增加,水分利用效率却随着灌水量的增加而降低。所有处理中,N3I3产量最高(5466.0~5727.5kg/hm^2),N3I2次之(5428.5~5678.5kg/hm^2),N1I1最小(4504.5~4804.3kg/hm^2),而N3I2的水分利用效率最大[12.11~12.82kg/(mm·hm^2)],N3I1次之[12.04~12.63kg/(mm·hm^2)],N1I3最小[9.79~10.58kg/(mm·hm^2)]。由此表明,水氮耦合对燕麦水分利用及产量具有显著互作效应,施氮量150kg/hm^2、灌溉定额337.5mm是西北绿洲灌区燕麦种植较佳的节水、高产水氮管理模式。

Irrigation and fertilization are the two most important methods to increase crop growth and yield. Understanding the water consumption characteristics and grain yield of oat （Avena saliva） under different wa-ter-nitrogen （N） regimes is useful to optimize oat cultivation. In the 2014 -2015 oat growing seasons, field ex-periments were conducted with three irrigation levels and three N application rates to study the effects of the water-N interaction on soil water consumption in the 0 -150 mm layer, soil evaporation, grain yield, and wateruse efficiency （WUE） of the oat variety ‘ Longyan 3 ’. The three irrigation amounts were 270 （I i） , 337. 5 （I2） · and 405 mm （I3） and the three N application rates were 90 （Ni） , 120 （N2） · and 150 kg/ha （N3）. The soil e-vaporation and the proportion of soil evaporation （E） to evapotranspiration （E/ET） decreased and then in-creased during the growing period. Under the same N application rate, E and its proportion of E/ET increased with increasing amounts of irrigation from the jointing to the filling stage, but decreased from the filling to the harvest stage. The oat water consumption and grain yield under a fixed N application rate were positively relat-ed to the amount of irrigation, whereas WUE was negatively related to the amount of irrigation. The highest grain yield of oat was in N313 （5466. 0 - 5727. 5 kg/h a ） ,followed by N312 （5428. 5 - 5678. 5 kg/h a ） , and then Nili（4504. 5 - 4804. 3 kg/ha）. The highest WUE was in N3I2[（12. 11 - 12. 82 kg/（mm · ha）] , followed by N3Ii [12. 04 - 12. 63 kg/（mm · ha）] , and then Nil3[9. 79 - 10. 58 kg/（mm · ha）]. The water-nitrogen interac-tion had significant effects on WUE and oat yield. Our results suggest that N application at 150 kg/ha com-bined with irrigation at 337. 5 mm is a water-saving method to cultivate oat with high-yields in the Northwest Oasis area.