Xu et al. (2026) Main-stem versus tiller-derived spike formation in winter wheat: Divergent water use strategies for long-term yield stabilization in saline-prone arid regions

Identification

• Journal: Agricultural Water Management
• Year: 2026
• Date: 2026-07-01
• Authors: Changkun Ma, Quanjiu WANG, Mingjiang Deng
• DOI: 10.1016/j.agwat.2026.110595

Research Groups

• State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Xi'an University of Technology
• Institute of Arid Region Ecological Water Conservancy, Xi'an University of Technology
• Eco-Hydraulic Research Center of the Xinjiang Uygur Autonomous Region (Academician and Expert Workstation, Department of Water Resources of the Xinjiang Uygur Autonomous Region)

Short Summary

This study investigates the effects of sub-ETc drip irrigation and seeding density on winter wheat productivity in saline-prone arid regions. The results show that a low-density planting strategy combined with moderate sub-ETc irrigation maintains yield stability through sustained post-anthesis photosynthesis, mediated by preferential deep-root water access to less-saline sub-soil.

Objective

• Investigate the divergent responses of main-stem versus tiller-derived spike formation to coupled water-deficit and salinity gradients across a realistic density spectrum.
• Characterize the associations among seeding density, root architecture, salt dynamics, and physiological buffering through integrated field measurements and structural equation modeling.
• Identify the seeding density×irrigation regime combination that maximizes irrigation water productivity while maintaining economic competitiveness under no-mulch cultivation systems typical of southern Xinjiang wheat production.

Study Configuration

• Spatial Scale: Field experiment conducted at a 7th Regiment, Alar City (40◦34′N, 81◦18′E, 1015 m a.s.l.), Xinjiang Uygur Autonomous Region, northwestern China.
• Temporal Scale: Three consecutive growing seasons (2022–2025) in the winter wheat cultivation period.

Methodology and Data

• Models used: Partial least squares path modeling (PLS-PM)
• Data sources: Field measurements, including soil electrical conductivity, root length density, specific root length, leaf net photosynthetic rate, stomatal conductance, and grain yield

Main Results

• Low-density planting strategy (D1) combined with moderate sub-ETc irrigation (W1) maintained 91.5% productive spike survival and exhibited 37.5% higher root length density in 60–100 cm.
• Deep-root proliferation was identified as the strongest mediator of post-anthesis photosynthesis, extending stay-green by 5.2 d under D1W1 treatment.
• The combination of low-density planting (D1) and moderate sub-ETc irrigation (W1) achieved stable three-year mean yield of 7.92 t ha⁻¹ and the highest irrigation water productivity (IWP = 2.07 kg m⁻³).

Contributions

• Original value of the article lies in its comprehensive investigation of the effects of sub-ETc drip irrigation and seeding density on winter wheat productivity in saline-prone arid regions.
• The study provides new insights into the mechanisms underlying yield stability under combined water-deficit and salinity stress.

Funding

• This research was funded by projects, programs, and reference codes:
  • State Key Laboratory of Eco-Hydraulics in Northwest Arid Region (Grant No. SKL2020XJ001)
  • Institute of Arid Region Ecological Water Conservancy (Grant No. IAREWC2022A01)
  • Xinjiang Uygur Autonomous Region Science and Technology Plan Project (Grant No. 2021AB011)

Citation

@article{Xu2026Mainstem,
  author = {Xu, Qi and Ma, Changkun and WANG, Quanjiu and Deng, Mingjiang},
  title = {Main-stem versus tiller-derived spike formation in winter wheat: Divergent water use strategies for long-term yield stabilization in saline-prone arid regions},
  journal = {Agricultural Water Management},
  year = {2026},
  doi = {10.1016/j.agwat.2026.110595},
  url = {https://doi.org/10.1016/j.agwat.2026.110595}
}