Nitrogen Dynamics and Sensor-Based Management for Inter-Seeded Maize-Soybean Cropping Systems

Overview

This research initiative addresses the declining nitrogen use efficiency (NUE) and environmental concerns associated with long-term monoculture corn cultivation in Alabama. The project investigates nitrogen trade-offs—including plant N uptake, accumulation, soil N losses, soil N pool, and availability—in soybean inter-seeded with maize cropping systems. By integrating field-based research with simulation modeling, the initiative aims to generate scientific data and knowledge on nitrogen dynamics, refine the DSSAT intercropping module, and develop agribusiness models for broader applicability in regions such as India and Bangladesh.

The research is co-designed with an Alabama farmer to ensure outcomes are practical, feasible, and evidence-based. Learnings will be generalized and simulated for scaling out and technology targeting, supporting wider adoption and the creation of new agribusiness models for the private sector.

Technical specifications

Research hypotheses:

• H1: Nitrogen trade-offs change significantly when soybean (legume) is inter-seeded with maize (non-legume), improving overall NUE. Dynamic nitrogen management through sensor-based GreenSeeker technology is essential for optimizing inter-seeding systems.
• H2: Refining the nitrogen module in the DSSAT intercropping model using nitrogen trade-off data and validation with IFDC data from India and Bangladesh will support technology targeting and agribusiness model development.

Field validation plot design:

• Sole corn crop with farmer-applied traditional inputs (control)
• Sole soybean crop with farmer-applied traditional inputs (control)
• Corn (March seeding) inter-seeded with soybean (June seeding) under four nitrogen management treatments:
  • 100% N dose for corn + 100% N dose for soybean
  • 100% N dose for corn + 50% N dose for soybean
  • Basal N dose for corn with GreenSeeker-based supplementation + basal N dose for soybean with GreenSeeker-based supplementation
  • Basal N dose for corn with GreenSeeker-based supplementation + 100% N dose for soybean based on GreenSeeker

Key technical elements:

• GreenSeeker sensor-based dynamic nitrogen management
• DSSAT intercropping simulation model refinement
• Assessment of N transfer from legume to non-legume crops
• Evaluation of soil N retention, ammonifying, and nitrifying capacities
• Comparative analysis of productivity, profitability, input use efficiencies, and soil health

Technology readiness level

This project is at an active field research and validation stage. Corn cultivation in Alabama runs from early March with harvest in July through September, while soybean inter-seeding occurs in June-July with harvest in October-November. Typical sole corn yields range from 140 to 180 bushels per acre. The project leverages existing farmer resources while establishing structured comparative research plots. Validation will incorporate IFDC field data from India and Bangladesh to support model refinement and broader geographic applicability. The initiative is positioned to generate evidence-based outcomes that can inform agribusiness model development and support technology targeting for wider adoption of inter-seeded cropping systems.