Articles
Model-based optimization of N-fertilization strategies, balancing production and nitrate leaching in horticultural crops using genetic optimization
Article number
1426_71
Pages
519 – 526
Language
English
Abstract
Intensive horticultural production is linked to pollution of surface and groundwater due to nitrate leaching of overfertilized crops.
In Flanders (Belgium), farmers should comply with strict regulations regarding maximal N-application and residual soil nitrate (<85 kg N03– ha‑1 at the end of the cycle, between October 1 and November 15). The high nitrogen demand and shallow rooting systems of most horticultural crops make balancing nitrogen availability and nitrogen losses challenging.
This study aimed to optimize fertilization of leeks through a model-based decision support system, limiting nitrogen leaching while maintaining yields.
This was achieved using a genetic optimization algorithm in combination with simulated data from the ECOFERT simulation model.
This approach was compared to the standard KNS advisory system in two field trials.
One trial had a high soil organic carbon (SOC) content (2.3%), and the other had a low SOC (0.9%). On the field with high SOC, the KNS recommended 136 kg N ha‑1, resulting in 118.3 kg NO3– ha‑1 residual nitrate.
The ECOFERT model advised no fertilizer application as the risk of exceeding the legal limit was too high.
This resulted in a 63% reduction of the residual soil nitrate (43.5 kg NO3– ha‑1) but also in a 10% yield loss (57 t ha‑1 compared to 63.5 t ha‑1). On the field with low SOC, ECOFERT recommended 165 kg N ha‑1, resulting in no yield loss (76.2 t ha‑1), a 21% reduction of applied nitrogen, and a 51% residual soil nitrate reduction (35.5 kg NO3– ha‑1). While the KNS system advised 209 kg N ha‑1 for a yield of 76 t ha‑1 and a residual nitrate of 71.8 kg NO3– ha‑1. This study showed that model-based fertilization could reduce N-input compared to the standard KNS advisory system.
In Flanders (Belgium), farmers should comply with strict regulations regarding maximal N-application and residual soil nitrate (<85 kg N03– ha‑1 at the end of the cycle, between October 1 and November 15). The high nitrogen demand and shallow rooting systems of most horticultural crops make balancing nitrogen availability and nitrogen losses challenging.
This study aimed to optimize fertilization of leeks through a model-based decision support system, limiting nitrogen leaching while maintaining yields.
This was achieved using a genetic optimization algorithm in combination with simulated data from the ECOFERT simulation model.
This approach was compared to the standard KNS advisory system in two field trials.
One trial had a high soil organic carbon (SOC) content (2.3%), and the other had a low SOC (0.9%). On the field with high SOC, the KNS recommended 136 kg N ha‑1, resulting in 118.3 kg NO3– ha‑1 residual nitrate.
The ECOFERT model advised no fertilizer application as the risk of exceeding the legal limit was too high.
This resulted in a 63% reduction of the residual soil nitrate (43.5 kg NO3– ha‑1) but also in a 10% yield loss (57 t ha‑1 compared to 63.5 t ha‑1). On the field with low SOC, ECOFERT recommended 165 kg N ha‑1, resulting in no yield loss (76.2 t ha‑1), a 21% reduction of applied nitrogen, and a 51% residual soil nitrate reduction (35.5 kg NO3– ha‑1). While the KNS system advised 209 kg N ha‑1 for a yield of 76 t ha‑1 and a residual nitrate of 71.8 kg NO3– ha‑1. This study showed that model-based fertilization could reduce N-input compared to the standard KNS advisory system.
Publication
Authors
J. Haumont, E. Schrevens, J. Diels, P. Lootens, T. De Cuypere, O. Bes, J. Bodyn, W. Saeys
Keywords
leek, soil nitrogen, fertilizer management, model-based DSS, crop simulation modelling, genetic optimization
Groups involved
- Division Precision Horticulture and Engineering
- Division Greenhouse and Indoor Production Horticulture
- 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 Vegetable Grafting
- Working Group Modelling Plant Growth, Environmental Control, Greenhouse Environment
- Working Group Protected Cultivation, Nettings and Screens for Mild Climates
- 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
- Division Landscape and Urban Horticulture
- Commission Agroecology and Organic Farming Systems
- Division Vegetables, Roots and Tubers
- Working Group Vertical Farming
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