ISHS Acta Horticulturae 802: IV International Symposium on Applications of Modelling as an Innovative Technology in the Agri-Food-Chain: Model-IT
USE OF CROPSYST TO SIMULATE GROWTH, ETC AND N UPTAKE FOR THE DEVELOPMENT OF IRRIGATION AND N FERTILISER PROGRAMS IN INTENSIVE VEGETABLE CROP PRODUCTION |
| Authors: | C. Martinez-Gaitan, M. Gallardo, R.B. Thompson, C.O. Stöckle, M.R. Granados, M.D. Fernandez, C. Gimenez |
| Keywords: | model, simulation, pepper, water, nitrogen, fertigation |
| Abstract:
Combined systems of drip irrigation and fertigation that are automatically controlled by programmers are commonly used in intensive vegetable production. Such systems are regularly used in substrate-grown crops, and are being increasingly used with soil-grown crops. These systems provide growers with the technical capacity to “spoon-feed” both water and nutrients as required. Doing so would optimise the use of water and N, and minimise deleterious N losses to the environment. Crop simulation models provide a means to effectively use this technical capacity for precise irrigation and N management. The crop simulation model CropSyst was used to simulate crop evapotranspiration (ETc), growth and N uptake of pepper grown in soil. The crop was grown in simple plastic greenhouses, as is widely used for vegetable production in south-east Spain. The FAO radiation equation was used to simulate ETc. This equation was more accurate for the greenhouse conditions than (a) Penman-Monteith and (b) FAO-Pan, which are alternatives available in CropSyst. Crop N uptake was simulated using (i) crop growth estimated from radiation interception and transpiration, and (ii) curves of dry matter to N content that were determined empirically. Following calibration, validations were conducted in different crops. These simulation routines are being incorporated into a management-oriented program decision support system that will enable growers to evaluate and improve water and nitrogen management of vegetable crops grown in plastic greenhouses. | |
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