Talasila (2026) Management Adaptations to Sustainably Increase Soybean Yield and Water Productivity Through Field Studies and Crop Modeling

Identification

• Journal: UKnowledge (University of Kentucky)
• Year: 2026
• Date: 2026-01-15
• Authors: Mounica Talasila
• DOI: 10.13023/etd.2025.605

Research Groups

• University of Kentucky
• Martin-Gatton College of Agriculture, Food and Environment
• Department of Plant and Soil Sciences
• Faculty: Montse Salmeron, Arthur Hunt

Short Summary

This study investigated optimal soybean management adaptations, including cultivar maturity group, planting date, and irrigation strategies, to sustainably increase yield and water productivity in the U.S. Mid-South through field experiments and crop modeling. It found that irrigation significantly enhances yield and stability, alters optimal planting windows, and that specific scheduling approaches can improve water use efficiency.

Objective

• To determine the optimal cultivar maturity group (MG) and planting date (PD) for maximizing soybean yield and improving water use metrics (Water Use Efficiency and Water Productivity) under both rainfed and irrigated conditions.
• To evaluate how irrigation alters existing PD and MG recommendations and influences Water Use Efficiency (WUE) and Water Productivity (WP) dynamics.
• To identify efficient irrigation scheduling strategies that optimize water resource allocation and improve irrigation water productivity without compromising yield.

Study Configuration

• Spatial Scale: Field experiments conducted in Lexington, Kentucky; crop modeling simulations for Lexington, KY, as a representative irrigation-transition region.
• Temporal Scale: Field experiments from 2017 to 2020; crop model simulations for 30 years (1991–2020).

Methodology and Data

• Models used: CROPGRO-Soybean model within the Decision Support System for Agrotechnology Transfer (DSSAT) v4.8.5.
• Data sources: Field experiments (2017-2020) in Lexington, Kentucky, under irrigated and rainfed conditions, with two planting dates and 16 soybean cultivars (MG 2-5). Historical weather data (1991-2020) for simulations.

Main Results

• Irrigation increased soybean yield by 12–117%, depending on planting date, maturity group, and seasonal rainfall distribution.
• Irrigation enhanced both WUE and WP during the driest year but decreased WP for some MG x PD combinations in wetter years.
• Irrigation effectively mitigates yield losses under water stress and enhances yield stability across variable climates.
• Under irrigation, the optimum planting window for maximum yield occurred approximately 20 days earlier and favored shorter maturity groups compared with rainfed conditions, particularly in dry years.
• Early planting in April increased yield potential but reduced WUE and WP, especially under rainfed management.
• Similar planting date and maturity group combinations could be identified that simultaneously optimized yield, WUE, and WP under both water regimes.
• The relative benefit of irrigation depended on the chosen water-use metric, with WUE and WP responding differently.
• Delaying irrigation until the R3 (beginning pod) reproductive stage reduced total irrigation volume without yield penalties.
• Soil moisture threshold-based irrigation scheduling (100% replenishment at 55% soil water threshold), combined with delaying irrigation to reproductive stages, maximized yield with minimized water use.

Contributions

• Provides a comprehensive evaluation of the interactive effects of cultivar maturity group, planting date, and irrigation on soybean yield and water productivity across varying climatic conditions.
• Quantifies the significant yield benefits and enhanced yield stability conferred by irrigation in a transitioning agricultural region.
• Identifies specific shifts in optimal planting windows and maturity group recommendations under irrigated versus rainfed conditions.
• Develops and evaluates practical irrigation scheduling strategies, demonstrating that delayed irrigation to reproductive stages or soil threshold-based methods can conserve water without yield loss, offering a framework for sustainable irrigation expansion.

Funding

• Kentucky Soybean Promotion Board Grant

Citation

@article{Talasila2026Management,
  author = {Talasila, Mounica},
  title = {Management Adaptations to Sustainably Increase Soybean Yield and Water Productivity Through Field Studies and Crop Modeling},
  journal = {UKnowledge (University of Kentucky)},
  year = {2026},
  doi = {10.13023/etd.2025.605},
  url = {https://doi.org/10.13023/etd.2025.605}
}