Modelling greenhouse-grown vegetable crops for optimisation of irrigation and nitrogen management

The main simulation models and model-based decision support systems (DSSs) that have been specifically developed or adapted to assist with irrigation and nitrogen (N) management of greenhouse-grown vegetable crops are reviewed. Models and DSSs will be presented that can be used with vegetable crops grown in soil and in soilless systems. The models and DSSs presented here can be used to create crop and site specific recommendations. Additionally, models that can be used for scenario analysis will also be included. Mechanistic models such as EU-ROTATE_N and TOMGRO have been used for scenario analysis applications of greenhouse-grown vegetable crops produced in soil or soilless systems. Several models such as the fertigation model have been developed for use in intensive greenhouse production in North-West Europe. The VegSyst simulation model calculates crop N uptake and crop evapotranspiration (ETc) for various vegetable species grown in low to medium technology greenhouses, in the Mediterranean Basin. The VegSyst-DSS decision support system incorporates the VegSyst simulation model and calculates daily recommendations of crop water and N requirements, and the applied N concentration in nutrient solutions where fertigation is used to apply all nutrients. VegSyst-DSS and similar DSSs can contribute to the optimisation of irrigation and N management through the preparation of crop and site specific plans for irrigation and N application for drip irrigated and fertigated crops. Practical aspects related to the use of DSSs based on models for on-farm crop management will also be discussed.