关键词: 一次灌溉, 氮肥运筹, 旱地, 冬小麦, 产量, 加工品质

Abstract:

【Objective】The objective of this study was to evaluate the effects of one-off irrigation and nitrogen (N) fertilizer management on grain yield and quality in dryland winter wheat (hereinafter referred to as wheat).【Method】From 2020 to 2022, the split-plot field experiment was conducted at the Mengjin, Yichuan and Luoning counties of Luoyang city in Henan province, China, in the typical dryland wheat production area at the intersection between Loess Plateau and Huang-Huai-Hai Plain. The two irrigation levels of no-irrigation during wheat growth period (I0) and soil-moisture-based one-off irrigation after regreening (I1, one-off supplemental irrigation was conducted to 85% of field capacity when the soil water content in the 0-40 cm soil layer after wheat regreening was lower than 60% of field capacity at the first time, there was only this irrigation during the whole growth stage) were assigned as the main plots; and the four N fertilizer managements of N0, N120, N180 and N240 were set as sub-plots, where N rates were 0, 120, 180 and 240 kg·hm^-2, respectively, and all of them were applied at sowing under I0 treatment, and 50% as basal, and 50% were applied along with the one-off irrigation under I1. The grain yield and protein yield, zinc content, protein and its components content, and main processing quality indicators of wheat were determined. 【Result】 Compared with I0, I1 significantly increased wheat grain yield and protein yield by 11.5%-73.0% and 9.1%-57.0%, respectively, in which the amplification enlarged with the increase of N rates, and that in the 2020-2021 was higher than that in the 2021-2022. However, I1 reduced the contents of zinc, and protein and its components in wheat grain, as well as the most indicators of processing quality compared with I0. Except for the globulin content at Yichuan in 2020-2021, compared with I0, I1 significantly decreased the content of zinc, protein and its components, and the processing quality of wheat grain. Among them, the content of zinc, albumin, globulin, gliadin, and glutenin were decreased by 5.0%-13.8%, 4.5%-14.1%, 6.4%-17.3%, 2.3%-24.8%, and 8.0%-13.9%, respectively, and the development time, stability time, wet gluten content, sedimentation value, extensibility, and maximum resistance were decreased by 5.3%-23.2%, 8.5%-51.1%, 2.0%-13.3%, 4.5%-18.1%, 4.6%-12.2% and 3.3%-10.6%, respectively. With the increase of N rate, wheat yield firstly increased and then decreased and wheat protein yield firstly increased and then stabilized under I0, while wheat yield firstly increased and then stabilized and wheat protein yield gradually increased under I1, however, the wheat quality indicators mostly tended to increase firstly and then stabilized under both I0 and I1. There were no significant differences between N240 and N180 for most quality indicators, but most of them were significantly higher than N120. The quality indicators of wheat grain under N120 were also significantly higher than that under N0. Considering the interaction effect, irrigation levels and N managements had significant interaction effects on yield and protein yield, but there was no interaction effect on most quality indicators. The grain yield under I1N180 did not change significantly but the protein yield was significantly decreased by 3.9%-4.9% compared with I1N240, however, both the grain yield and protein yield under I1N180 were significantly increased compared with other treatments. Although the content of protein and protein components and the processing quality in wheat grain under I1N180 were significantly lower than that under I0N180 and I0N240, these quality indicators were not significantly lower than that under I1N240. 【Conclusion】 The soil-moisture-based one-off irrigation after regreening combined with the N rate of 180 kg·hm^-2 and 50% N topdressing along with irrigation (I1N180) could synchronously improve the grain yield and stabilize the grain quality in dryland wheat. Therefore, I1N180 was suitable for wheat production in the dryland area, where one-off irrigation was guaranteed due to High-Standard Farmland Construction Program.

Key words: one-off irrigation, nitrogen fertilizer management, dryland, winter wheat, grain yield, quality