摘要
为探讨固定道小麦栽培方式下适宜的水氮组合,以低水1200(W_1)、中水2400(W_2)、高水3600 m3·hm^(-2)(W_3)为主处理,0(N_0)、低氮90(N_1)、中氮180(N_2)、高氮270kg·hm^(-2)(N_3)为副处理,采用裂区设计,对固定道垄作栽培方式下水氮互作对春小麦根系生长及产量的影响进行了研究.结果表明:水氮互作能显著影响春小麦根干质量密度(RWD),RWD随着小麦生育期的进程表现为先增大后减小的趋势,在灌浆期达最大;RWD对施氮量的响应取决于灌溉量,在W_1下,RWD在N_1处理下最大,在W_2下,RWD随着施氮量的增加在N_2处理下最大,在W_3下,RWD随着施氮量的增加在N_3处理下最大;不同灌溉处理下RWD表现为W_2>W_3>W_1;施氮与灌水显著影响RWD,表现为灌水>氮肥>水氮互作,在W_2N_2处理下最大.根冠比随着灌水量与施氮量的增加逐渐减小,在W_1N_0处理下根冠比最大;85%以上的小麦根系分布于0~40 cm土层,产量与0~40 cm土层RWD呈显著抛物线回归关系,与40~60cm土层RWD呈显著线性正回归关系.W_2灌溉条件可以促进小麦根系向中下层(40~60 cm)分布;灌水施氮能显著影响春小麦籽粒产量与生物产量,生物产量随着施氮量和灌水量的增加而增加,籽粒产量在W_2N_2最大;灌水生产力随灌水量的增加逐渐降低,氮肥农学利用率随施氮量的增加而减小.因此,在固定道垄作栽培方式下,施肥量与灌水量控制在N_2(180kg·hm^(-2))与W_2(2400 m^3·hm^(-2))条件下有利于促进根系生长,进而提高春小麦籽粒产量及水氮利用效率,是河西灌区固定道小麦栽培方式下适宜的水氮组合.
To establish an optimum combination of water and nitrogen for spring under permanent raised bed （PRB） tillage, a field investigation was carried out to assess effects of irrigation and N application on root growth, yield, irrigation water productivity and N efficiency. The experiment fol- lowed a completely randomized split-plot design, taking furrow irrigation 1200 m3 . hm-2 （W1 ）, 2400 m3 . hm-2 （W2）, 3600 m3 . hm-2 （W3） as main plot treatments, and N rates （0, 90, 180, 270 kg . hm-2） the sub-plot treatments. Our results showed that the root mass density （RWD） was significantly affected by irrigation and N application, the RWD of spring wheat reached a maximum at the filling stage, followed by a slow decline until maturity, while the effect of N on RWD depen- ded on soil water conditions. The application of N2 produced the maximum RWD under W2 irriga- tion, the application of N1 produced the maximum RWD under W1 irrigation, and the application of N3 produced the maximum RWD under W3 irrigation. The order of irrigation regime effect on RWD of spring wheat was W2〉W3〉W1. The order of irrigation regime and N rate effect on RWD of spring wheat was irrigation〉N 〉irrigation and N interaction. W2 Nz treatment produced the highest RWD value. The root-to-shoot ratio （R/S） descended with the rising of irrigation water and nitrogen amount, and the combined treatment （W1N0） produced the maximum R/S. The root system was mainly distributed in the 0-40 cm soil layer, in which the RWD accounted for 85% of the total RWD in 0-80 cm soil depth. There was a significantly positive relationship between RWD in the 0-40 cm and the yield of spring wheat, RWD in the 40-60 cm had higher linear dependence on the yield of spring wheat. W2 increased the proportion of RWD in the deep soil layer （40-60 cm）. The irrigation and N rate had a significant impact on biomass and grain yield of spring wheat, the biomass increased as the N rate and water amount increased, W2 N2 treatment produced the highest grain yield, irrigation water productivity descended with increasing the irrigation amount, and the nitrogen agronomic efficiency descended with increasing N rate. It was concluded that the irrigation level W2 （2400 m3 . hm-2） and nitrogen level N2 （180 kg .hm-2） could be recommended as the best combination of water and N, which promoted the root growth, improved grain yield, water and nitrogen use efficiencies of spring wheat production under PRB tillage in the experimental area.
出处
《应用生态学报》
CAS
CSCD
北大核心
2016年第5期1511-1520,共10页
Chinese Journal of Applied Ecology
基金
公益性行业(农业)科研专项(201503125-02)
中澳国际合作项目(SMCN/2002/094)
甘肃省农业科技创新项目(GNCX-2014-35)资助~~
关键词
固定道
水氮互作
春小麦
根系
籽粒产量
permanent raised bed
irrigation and nitrogen application
spring wheat
root
grainyield.
