Abstract: In order to clarify the effects of water and nitrogen coupling on water consumption characteristics of oil flax in typical semiarid gully area of Loess Plateau and select the suitable local irrigation amount and fertilization application rate, the field experiment was conducted. The effects of water and nitrogen coupling on water use characteristics at different growth stages, grain yield, and water use efficiency of oil flax were studied by three-factor split. Two species of Lunxuan 2 (V1) and Dingya 22 (V2) were selected as the main area, three irrigations of 0 (W1), 1 200 (W2), and 1 800 m³·hm^-2 (W3) were set as the sub-area, and three nitrogen fertilizer gradients of 0 (N1), 60 (N2), and 120 kg·hm^-2 (N3) were the secondary sub-areas. The results showed that the irrigation amount and nitrogen rate mainly affected the soil water content above 100 cm soil depth, indicating that W3 was higher than W2 and W1, and N3 was higher than N2 and N1. The average soil water content of W3 in the 0~100 cm soil layer during maturity was 9.04% and 30.93% higher than W2 and W1, respectively, and N3 was 5.96% and 9.68% higher than N2 and N1, respectively. The variety, irrigation and nitrogen fertilizer significantly affected yield. The yield of V2 increased by 8.94% compared with the yield of W3 and W2 increased by 40.35% and 27.42%, respectively, compared with W1, and the yield of N3 and N2 increased by 13.86% and 8.50%, respectively, compared with N1. The interactive effects between water and nitrogen, variety and water, and variety and nitrogen were significant (P<0.01), however, the interactive effects among variety, water and nitrogen were not significant. The agronomic utilization efficiency decreased with the increase of irrigation amount and nitrogen application rate, the partial productivity increased with the increase of irrigation amount, and decreased with the increase of nitrogen application rate. These results suggested that selecting V2 with 1 800 m³·hm^-2 irrigation amount and 60 kg N·hm^-2 nitrogen fertilizer in test region was the best choice, which can increase grain yield and improve soil moisture absorption of oil flax in dryland. The results provide a theoretical basis for high-yield and high-efficiency cultivation of oil flax.

Key words: oil flax, water-nitrogen coupling, water consumption characteristic, grain yield, water use efficiency

摘要： 为明确水氮耦合效应对陇中黄土高原半干旱丘陵沟壑区胡麻耗水特性的影响,筛选出适宜当地的灌水量和施肥量,采用三因素裂区试验设计,以轮选2号(V1)、定压22号(V2)2个胡麻品种为主区,3个灌水量0(W1)、1 200(W2)和1 800 m³·hm^-2(W3)为副区,3个氮肥梯度0(N1)、60(N2)和120 kg·hm^-2(N3)为副副区,研究水氮耦合对胡麻不同生育时期的耗水特性、产量及水分利用效率的影响。结果表明,灌水量和施氮量主要影响100 cm以上土层土壤含水量,表现为W3>W2>W1,N3>N2>N1,成熟期0~100 cm土层平均土壤含水量W3较W2、W1分别高9.04%和30.93%,N3较N2、N1分别高5.96%和9.68%;品种、灌水、氮肥对产量有显著影响,V2较V1增加8.94%,W3、W2较W1分别增加40.35%和27.42%,N3、N2较N1分别增加13.86%和8.50%,除VXN外,各处理两因素间交互作用显著 (P<0.01),而三因素间交互作用不显著;农学利用率随着灌水量、施氮量的增加而下降,偏生产力随着灌水量的增加而增加,随着施氮量的增加而下降。综合评价水氮互作效应对胡麻耗水特性、产量、水分利用效率及肥料利用效率的影响,建议在试验区条件选择V2品种、灌水为1 800 m³·hm^-2,施氮量为60 kg N·hm^-2。综上,适宜的水氮耦合模式在增加旱地胡麻籽粒产量、促进土壤水分吸收的基础上,能够保证胡麻的高产高效。本研究结果为旱区胡麻高产栽培技术提供了理论依据。

关键词: 胡麻, 水肥耦合, 耗水特性, 产量, 水分利用效率