Articles
Modelling tomato crop growth and development in relation to nitrogen fertilization under high altitude cold tropical conditions
Article number
1271_38
Pages
279 – 286
Language
English
Abstract
Nowadays, crop models are a widespread tool for both research and production activities.
However, most of the models were developed and calibrated for potential conditions at places where there is a narrow gap between potential and actual yields.
The objective of this work was to incorporate the effect of nitrogen (N) supply in a tomato crop growth model calibrated for high altitude tropical conditions.
We carried out field experiments to determine the effect of N fertilization on plant parameters such as leaf area (LA) and allocation of dry matter (DM) in fruits.
A total of 10 treatments ranging from 196 to 1114 N kg ha‑1 were evaluated, six of them were used in the model calibration and the remaining four were reserved for validation.
Plant development was determined by means of accumulated thermal time (ATT) using a base temperature of 10°C. LA results were fitted with a nonparametric model to predict the changes in LA as response to N supply.
This N-model was introduced as a module within the tomato model.
The N-module calculates LA for a given amount of soil N available and ATT. Simultaneously, a nitrogen stress factor (NSF) was calculated as the ratio between daily available soil N per plant and N demand to reach the potential growth.
If NSF is less than one, a leaf area reduction factor (LARF) was calculated as the ratio among LA estimated by the nonparametric model and that calculated by the potential model.
In this way, a deficient N-supply affects plant growth by correcting the leaf DM produced at the end of each day by LARF. The performance of the model was satisfactory as shown by statistics such as the root mean square error, model efficiency and coefficient of determination.
However, most of the models were developed and calibrated for potential conditions at places where there is a narrow gap between potential and actual yields.
The objective of this work was to incorporate the effect of nitrogen (N) supply in a tomato crop growth model calibrated for high altitude tropical conditions.
We carried out field experiments to determine the effect of N fertilization on plant parameters such as leaf area (LA) and allocation of dry matter (DM) in fruits.
A total of 10 treatments ranging from 196 to 1114 N kg ha‑1 were evaluated, six of them were used in the model calibration and the remaining four were reserved for validation.
Plant development was determined by means of accumulated thermal time (ATT) using a base temperature of 10°C. LA results were fitted with a nonparametric model to predict the changes in LA as response to N supply.
This N-model was introduced as a module within the tomato model.
The N-module calculates LA for a given amount of soil N available and ATT. Simultaneously, a nitrogen stress factor (NSF) was calculated as the ratio between daily available soil N per plant and N demand to reach the potential growth.
If NSF is less than one, a leaf area reduction factor (LARF) was calculated as the ratio among LA estimated by the nonparametric model and that calculated by the potential model.
In this way, a deficient N-supply affects plant growth by correcting the leaf DM produced at the end of each day by LARF. The performance of the model was satisfactory as shown by statistics such as the root mean square error, model efficiency and coefficient of determination.
Authors
M.A. Castillo, X. Reynafarje, R. Gil, C.R. Bojacá, E. Schrevens
Keywords
crop modelling, nitrogen supply, nonparametric model, potential yield
Groups involved
- Division Greenhouse and Indoor Production Horticulture
- Division Precision Horticulture and Engineering
- Division Plant-Environment Interactions in Field Systems
- Working Group Nettings in Horticulture (subgroup of Protected Cultivation in Mild Winter Climates)
- Working Group Light in Horticulture
- Working Group Organic Greenhouse Horticulture
- Working Group Modelling Plant Growth, Environmental Control, Greenhouse Environment
- Working Group Protected Cultivation, Nettings and Screens for Mild Climates
- Working Group Vegetable Grafting
- Working Group Computational Fluid Dynamics in Agriculture
- Working Group Design and Automation in Integrated Indoor Production Systems
- Working Group Mechanization, Digitization, Sensing and Robotics
- Working Group Greenhouse Environment and Climate Control
- Commission Agroecology and Organic Farming Systems
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