Articles
Deep percolation estimation for irrigation efficiency assessment in horticultural crops using a parsimonious integrated data-driven layered-bucket framework
Article number
1468_54
Pages
417 – 424
Language
English
Abstract
Mediterranean horticulture faces chronic water scarcity and has adopted deficit-irrigation strategies alongside digitalization to sustain productivity.
Nevertheless, common metrics like irrigation water productivity (WPi) or the ratio of applied water to crop evapotranspiration (ETc) overlook water losses below the active root zone.
This study aimed to estimate deep percolation as an additional metric of irrigation efficiency.
We evaluated lettuce and melon (open field) and sweet pepper (greenhouse) crops with high WPi and water supplies 50-95% of ETc in the Region of Murcia (Spain). Plots were monitored using a digital platform that recorded soil volumetric water content at 10 cm intervals (to 30 cm in lettuce, 60 cm in melon and pepper), irrigation volume and rainfall data.
We implemented a data-driven, layered-bucket model with local partitioning of irrigation and rainfall inputs.
The evapotranspiration (ET) was estimated as the strictly positive residual reconciling modelled pre-assimilation soil states with sensor data, constrained by field capacity and saturation.
Deep percolation was calculated as the downward flux crossing the active root zone, defined as the minimum depth accounting for ≥90% of ET. The active root-zone obtained was 0-30 cm for lettuce and 0-40 cm for melon and sweet pepper.
Despite irrigation levels below ETc, deep percolation was often substantial.
In melon (51.6% of ETc), total deep percolation was 16.0%, with 6.6% attributable to irrigation.
In sweet pepper ‘Tamarin’ (56.6% ETc), deep percolation reached 18.6%, while in ‘Bemol’ it rose proportionally with irrigation, reaching 33.7% at 81.6% ETc. In contrast, lettuce (85.4% ETc) exhibited just 6.6% of deep percolation.
These results show that total water applied is not a sufficient indicator of efficiency.
Instead, precise knowledge of the active root zone could significantly reduce water loss.
Nevertheless, common metrics like irrigation water productivity (WPi) or the ratio of applied water to crop evapotranspiration (ETc) overlook water losses below the active root zone.
This study aimed to estimate deep percolation as an additional metric of irrigation efficiency.
We evaluated lettuce and melon (open field) and sweet pepper (greenhouse) crops with high WPi and water supplies 50-95% of ETc in the Region of Murcia (Spain). Plots were monitored using a digital platform that recorded soil volumetric water content at 10 cm intervals (to 30 cm in lettuce, 60 cm in melon and pepper), irrigation volume and rainfall data.
We implemented a data-driven, layered-bucket model with local partitioning of irrigation and rainfall inputs.
The evapotranspiration (ET) was estimated as the strictly positive residual reconciling modelled pre-assimilation soil states with sensor data, constrained by field capacity and saturation.
Deep percolation was calculated as the downward flux crossing the active root zone, defined as the minimum depth accounting for ≥90% of ET. The active root-zone obtained was 0-30 cm for lettuce and 0-40 cm for melon and sweet pepper.
Despite irrigation levels below ETc, deep percolation was often substantial.
In melon (51.6% of ETc), total deep percolation was 16.0%, with 6.6% attributable to irrigation.
In sweet pepper ‘Tamarin’ (56.6% ETc), deep percolation reached 18.6%, while in ‘Bemol’ it rose proportionally with irrigation, reaching 33.7% at 81.6% ETc. In contrast, lettuce (85.4% ETc) exhibited just 6.6% of deep percolation.
These results show that total water applied is not a sufficient indicator of efficiency.
Instead, precise knowledge of the active root zone could significantly reduce water loss.
Authors
P. Berríos, A. Temnani Rajjaf, A. Pérez-Ruiz, E. Baldi, M. Toselli, A. Pérez-Pastor
Keywords
digitalization, evapotranspiration, root distribution, sustainability, water productivity
Groups involved
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