Modified energy cascade model with plant growth integration for controlled environment agriculture

Overview

This research proposes an enhancement to the Modified Energy Cascade (MEC) model by incorporating plant growth and development (PGD) dynamics. The current MEC model tends to overestimate stomatal conductance and photosynthesis when crops are exposed to off-nominal vapor pressure deficit (VPD) and temperature conditions. By adding PGD, the model will more accurately reflect long-term physiological changes in plants responding to extended or severe environmental stress.

The improved model addresses a critical need in controlled environment agriculture (CEA) and space-based farming systems, where equipment malfunctions and power failures can cause rapid environmental swings. A more accurate predictive tool enables farmers and mission planners to prepare for and recover from such events, improving overall farm resilience. The model could also serve as the foundation for a decision support system to guide operational responses during environmental disturbances.

Technical specifications

Key features and approach:

• Converts the existing single "big leaf" MEC architecture into a concentric circle representation, where each circle corresponds to a time period of plant growth
• Older plants are represented by more circles, capturing developmental progression over time
• Incorporates plant growth and development feedback to correct overestimation of stomatal conductance and photosynthesis under high VPD and temperature
• Builds on prior validation showing that spatial splitting of the big leaf does not compromise model performance
• Supports nine crop types currently, with potential to expand to additional crops as funding permits
• Will be delivered as both a web browser-based platform and a standalone downloadable program

Validation methodology:

• Growth chamber experiments with lettuce grown under combinations of high and low temperature and VPD
• Monitoring of photosynthesis, gas exchange, and fluorescence parameters
• Side-by-side comparison of the original and enhanced models, analyzing best fit, sensitivity, and degree of complexity

Technology readiness level

The base MEC model is already designed for and actively used in space and controlled environment agriculture applications. Recent published work has identified the overestimation problem under high VPD and temperature, and prior research has demonstrated the feasibility of splitting the big leaf architecture for spatial modeling. The project is at an early-to-mid research stage, with the next phase focused on model restructuring, growth chamber validation, and software platform development. Additional crop validation and broader testing remain contingent on available time and funding.