Articles
Validation of an adapted soil-plant model to study the water and nitrogen flows of Colombian greenhouse tomato systems
Article number
1296_57
Pages
441 – 448
Language
English
Abstract
The purpose of the present work was to validate a soil-plant model to represent, besides crop growth, the soil water and nitrogen dynamics.
We used a soil model developed for temperate conditions coupled to a tomato growth model calibrated and validated locally.
Additionally, the evapotranspiration module was changed to the one of Stanghellini, which is recognized as more appropriate to estimate the evapotranspiration inside greenhouse crops, especially for tomato.
The last significant modification corresponded to change the soil temperature module since the original model version incorporates an approach able to simulate the soil temperature only under temperate seasonal climate variations.
The model, which is programmed in the R statistical language, uses as inputs climate data (solar radiation, air temperature, humidity and wind speed), soil characteristics (e.g., pH, nitrogen content, bulk density and moisture, lower limit, field capacity and saturation), crop management practices (e.g., planting date, plant density, cycle duration), as well as irrigation and fertilization strategies.
The field data for the validation came from an experiment carried out in the main greenhouse tomato production area of Colombia.
The model was validated by comparing the simulated values against the observed ones.
Two goodness-of-fit measures were used to evaluate the model fit: Nash-Sutcliffe modeling efficiency (NSE) and percent bias (PBias). The plant model, soil water movement and soil temperature showed satisfactory performance according to the measures employed.
Although the experimental data demonstrated that the simulated soil nitrogen contents follow the observed tendency, the NSE score showed the poor soil N module performance.
Based on the above, extra future calibration and validation experiments are needed to improve the accuracy of the proposed model.
We used a soil model developed for temperate conditions coupled to a tomato growth model calibrated and validated locally.
Additionally, the evapotranspiration module was changed to the one of Stanghellini, which is recognized as more appropriate to estimate the evapotranspiration inside greenhouse crops, especially for tomato.
The last significant modification corresponded to change the soil temperature module since the original model version incorporates an approach able to simulate the soil temperature only under temperate seasonal climate variations.
The model, which is programmed in the R statistical language, uses as inputs climate data (solar radiation, air temperature, humidity and wind speed), soil characteristics (e.g., pH, nitrogen content, bulk density and moisture, lower limit, field capacity and saturation), crop management practices (e.g., planting date, plant density, cycle duration), as well as irrigation and fertilization strategies.
The field data for the validation came from an experiment carried out in the main greenhouse tomato production area of Colombia.
The model was validated by comparing the simulated values against the observed ones.
Two goodness-of-fit measures were used to evaluate the model fit: Nash-Sutcliffe modeling efficiency (NSE) and percent bias (PBias). The plant model, soil water movement and soil temperature showed satisfactory performance according to the measures employed.
Although the experimental data demonstrated that the simulated soil nitrogen contents follow the observed tendency, the NSE score showed the poor soil N module performance.
Based on the above, extra future calibration and validation experiments are needed to improve the accuracy of the proposed model.
Publication
Authors
R. Gil, C.R. Bojacá, R. Heuts, E. Schrevens
Keywords
soil water movement, tropical agriculture, crop modeling, tomato, Colombia
Groups involved
- Division Precision Horticulture and Engineering
- Division Greenhouse and Indoor Production Horticulture
- Working Group Organic Greenhouse Horticulture
- Working Group Protected Cultivation, Nettings and Screens for Mild Climates
- Working Group Light in Horticulture
- Working Group Vegetable Grafting
- Working Group Computational Fluid Dynamics in Agriculture
- Working Group Mechanization, Digitization, Sensing and Robotics
- Working Group Modelling Plant Growth, Environmental Control, Greenhouse Environment
- Working Group Greenhouse Environment and Climate Control
- Working Group Design and Automation in Integrated Indoor Production Systems
- Commission Agroecology and Organic Farming Systems
- Division Landscape and Urban Horticulture
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