Real-time greenhouse nutrient uptake estimation via continuous crop growth monitoring

Overview

This solution offers greenhouse operators a direct and continuous method for estimating mineral nutrient uptake in tomato crops by monitoring plant biomass accumulation in real time. Traditional nutrient management relies on indirect measurements or predictive models, which can lead to over- or under-fertilization. By directly measuring plant weight and correlating it with known nutrient concentrations in plant tissue, growers can obtain precise, ongoing estimates of nutrient consumption for nitrogen, phosphorus, potassium, and sulfur.

The approach is grounded in the principle that plants maintain internal nutrient concentrations within a narrow range. As a result, nutrient uptake is closely tied to growth rate. This allows biomass accumulation to serve as a reliable proxy for nutrient demand, enabling more efficient fertilizer management, reduced waste, and improved crop performance.

Technical specifications

Core methodology:

• Continuous weighing devices measure plant biomass accumulation directly in the greenhouse
• IoT sensors capture real-time growth data without requiring predictive growth models
• Periodic sampling of drainage solution determines nutrient content in the root zone
• Lab analysis quantifies dry biomass and the concentration of each nutrient within plant tissue
• A calculation module converts biomass data into nutrient uptake estimates for N, P, K, and S

Key features:

• Replaces model-based estimation with direct, sensor-driven measurement
• Validated approach previously demonstrated in lettuce crops using solar radiation and air temperature inputs
• Applicable to greenhouse tomato production systems
• Enables data-driven fertigation decisions based on actual plant demand

Technology readiness level

The underlying hypothesis was previously validated in lettuce crops by Dr. Albornoz using a photosynthesis-based growth model combined with nutrient content analysis. The current proposal advances the approach by applying IoT-based continuous weighing devices to greenhouse tomato crops, eliminating dependence on growth models. Future validation will involve establishing a greenhouse tomato crop equipped with continuous weighing devices, periodic drainage sampling, and laboratory biomass analysis to quantify nutrient uptake with precision.