Effects of irrigation and nitrogen fertilizer management on wheat grain baking quality based on the SiriusQuality2 crop model

Abstract

The baking quality of wheat grain is significantly affected by irrigation and nitrogen fertilizer management. This study aimed to model the impacts of nitrogen and water stress on winter wheat grain protein composition using SiriusQuality2. SiriusQuality2 was calibrated by using sufficient nitrogen and water treatments and used to evaluate 16 treatments in semi‐arid regions. Then, simulated baking quality and yield over a past 51‐year period were used to screen and optimize the selected 203 management practices. The evaluated simulation results suggest that all relative root mean square errors were less than 0.3, and the simulation results were excellent or good. Irrigation and nitrogen fertilization were beneficial to yield and grain protein content (GPC), while grain baking quality had adverse responses to irrigation. The GPC no longer increased, and the baking quality decreased with excess nitrogen fertilization (262.5 kg ha−1). Increasing the irrigation frequency and days after sowing were always conducive to baking quality. The optimal management, with a basal dressing of 315‐kg ha−1 nitrogen fertilization and 180‐mm irrigation depth at the wintering stage and jointing stage, was selected. Optimized management practices could simultaneously meet the multiple requirements of high grain quality and yield.

Wheat GSPs and Processing Quality Are Affected by Irrigation and Nitrogen through Nitrogen Remobilisation

“…Previous reports also found that nitrogen application could influence the effect of irrigation on protein content; for example, irrigation in the range of 0-225 mm had a diluting effect on grain quality, while protein content and wet gluten content were decreased with increasing irrigation, and this effect could be diminished by nitrogen application [31]. Moderately high nitrogen fertilisation under water deficit conditions not only alleviated losses of grain yield caused by water deficit, but also increased protein accumulation [15,48]. Our current work showed that high nitrogen fertilisation significantly increased GSP content under no irrigation conditions in HF conditions, but it decreased significantly under two irrigation steps.…”