Seedling-Stage Deficit Irrigation with Nitrogen Application in Three-Year Field Study Provides Guidance for Improving Maize Yield, Water and Nitrogen Use Efficiencies

Abstract

Deficit irrigation (DI) was acknowledged as an effective technique to improve water use efficiency (WUE) without significant yield reduction. In this study, a 3-year field experiment was conducted in Northeast China during 2017–2019 to investigate the combined effects of 3-week DI from 3-leaf stage and N fertilization on maize seedling growth and determine the resulting impacts on silking growth and yield formation, N use efficiency (NUE) and WUE. Results showed that seedling-stage DI decreased leaf area and photosynthesis, thus significantly limited shoot and root dry biomass for maize seedling, compared to well-watered (WW) plants. In 2017 and 2019, seedling-stage DI positively improved seedling growth with higher root: shoot ratio and enhanced drought tolerance, under higher initial soil water contents (SWC) with sufficient precipitation before DI. The DI-primed plants showed similar or better performances on reproductive growth, grain yield, WUE and NUE compared to WW plants, even experiencing heavy rainfall or drought stresses around the silking stage. However, the contrasting results were observed in 2018 with negative DI effects on seedling and silking growth and final yield, probably due to less rainfall and lower SWC before DI. In all 3 years, N fertilization had significant compensatory effects on limited seedling growth under DI, and its effect was much less in 2018 than other years due to adverse early climate. The principal component and correlation analysis revealed maize silking growth, grain yield, NUE and WUE were strongly related to the seedling growth as affected by water and N managements under various climatic conditions. In conclusion, a short-term and moderate DI regime—adopted at the seedling stage under higher initial SWC and coupled with an appropriate N fertilization—is beneficial to control redundant vegetative growth while optimizing root development, therefore effectively improving drought tolerance for maize plants and achieving higher grain yield, WUE and NUE.

Morpho-Physiological and Biochemical Responses of Maize Hybrids under Recurrent Water Stress at Early Vegetative Stage

“…This, in turn, results in a reduction in leaf area and vegetative growth, as well as a decrease in cell size due to lower water potential. Leaf elongation is determined by turgor pressure, light interception, and flux assimilation [19][20][21].…”

Optimizing Nitrogen Application for Enhanced Barley Resilience: A Comprehensive Study on Drought Stress and Nitrogen Supply for Sustainable Agriculture

“…Křen et al (2014) acknowledged that the timely and accurate prediction of grain yield and quality in spring barley is an essential requirement for efficient crop management [38]. To mitigate yield losses in plant objects due to high temperatures, it is crucial to apply the optimal amount of total nitrogen [10,39,40]. However, in the present study, in the later growth phases, starting from tillering, stress had a detrimental effect on grain yields.…”

Water and Nitrogen Coupling Increased the Water-Nitrogen Use Efficiency of Oilseed Flax

“…Crop yield components play a vital role in determining grain yield and these can be affected by variety, environmental conditions, and agronomic management [ 27 ]. Previous studies have demonstrated that crop yield components can be regulated by irrigation and nitrogen [ 28 , 29 ]. In this study, increasing irrigation under the same nitrogen level significantly increased the EC, as did increasing nitrogen application amounts under the same irrigation level ( Table 3 ).…”