Search

Developed by INRAE, Optirrig is a software tool for generating, analysing and optimising irrigation scenarios. It is based on a simplified description of plant growth according to the evolution of water and nitrogen resources in the soil. It compares the merits of different irrigation strategies according to different constraints (water quota, periods of limited availability, prefectoral decrees, water and energy costs), for operational objectives at the plot, farm or territory level.

Optirrig est un outil logiciel de génération, d'analyse et d'optimisation de scénarios d'irrigation qui a été développé par INRAE. Il s'appuie sur une description simplifiée de la croissance des plantes en fonction de l'évolution des ressources en eau et en azote du sol. Il permet de comparer les mérites de différentes stratégies d’irrigation en fonction de différentes contraintes (quota d’eau, périodes de disponibilité limitée, arrêtés préfectoraux, coût de l'eau et de l'énergie), pour des objectifs opérationnels à l'échelle de la parcelle, de l'exploitation ou du territoire.

Agrivoltaism is the association of agricultural and photovoltaic energy production on the same land area, coping with the increasing pressure on land use and water resources while delivering a clean and renewable energy. However the solar panels located above the cultivated plots also have a seemingly unexplored yet effect on rain redistribution, sheltering large parts of the plot but redirecting concentrated fluxes on a few locations. The spatial heterogeneity in water amounts observed on the ground is high in the general case; its dynamical patterns are directly attributable to the mobile panels through their geometrical characteristics (dimensions, height, coverage percentage) and the strategies selected to rotate them around their support tube. A coefficient of variation is used to measure this spatial heterogeneity and to compare it with the coefficient of uniformity that classically describes the efficiency of irrigation systems. A rain redistribution model (AVrain) was derived from literature elements and theoretical grounds then validated from experiments in both field and controlled conditions. AVrain simulates the effective rain amounts on the plot from a few forcing data (rainfall, wind velocity and direction) thus allows real-time strategies that consist in operating the panels so as to limit rain interception mainly responsible for the spatial heterogeneities. Such avoidance strategies resulted in a sharp decrease of the coefficient of variation, e.g. 0.22 against 2.13 for panels held flat during one of the monitored rain events, that is a fairly good uniformity score for irrigation specialists. Finally, the water amounts predicted by AVrain were used as inputs to HYDRUS-2D for a brief exploratory study on the impact of the presence of solar panels on rain redistribution at shallow depths within soils : similar, more diffuse patterns were simulated and coherent with field measurements. [ABSTRACT FROM AUTHOR]