The AGRICOLUS Precision Irrigation System is integrated within a decision support system (DSS), which applies knowledge in weather and climate for the qualitative and quantitative improvement of agricultural production. The current proof of concept of this technology will be advanced and validated in the field by WATERAGRI. The irrigation plan encoded in the DSS is based on the prediction of the soil water content in the root zone and daily crop water requirements using a water balance model (part of the AGRICOLUS Precision Irrigation System), which combines crop, weather and soil databases, as well as historical and forecasting weather data. The main functions of the DSS includes real-time irrigation management, decision-making support, user-custom irrigation scheduling, simulation of soil water dynamics in the root zone, evaluation of the effect of certain irrigation schedule on crop yield reduction, and database management.
The crop simulation model and the water requirement calculations of the DSS work on a daily time step. The modelling approach is based on the continuity equation applied to the soil layer explored by roots. Crop evapotranspiration losses are evaluated at field level with an algorithm that simulates the reference crop evapotranspiration, the maximum crop evapotranspiration and the real crop evapotranspiration.
The AGRICOLUS Precision Irrigation System output, which is updated daily, includes the following information:
- crop water status and irrigation requirements as well as temporal patterns of soil moisture level compared to upper (soil optimal moisture status to be reached with irrigation) and
- lower (beginning of stress, when irrigation is mandatory) thresholds.
Additional data output given by the model includes the phenological phase, crop coefficient and water stress coefficient. Likewise, numerical models simulating the surface and subsurface resources can be linked to this decision support system. This allows to analyse how providing irrigation water will affect water storage in surface and subsurface reservoirs in the short and long term. It also allows to study the effect of in-stream measures on soil moisture storage.