Evaluation of the VegSyst model with muskmelon to simulate crop growth, nitrogen uptake and evapotranspiration

• Published in: Agricultural water management Vol. 101; no. 1; pp. 107 - 117
• Main Authors: Gallardo, M., Giménez, C., Martínez-Gaitán, C., Stöckle, C.O., Thompson, R.B., Granados, M.R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2011; Elsevier
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agronomy. Soil science and plant productions; asexual reproduction; Biological and medical sciences; Biomass; biomass production; Computer simulation; cooling; Crop growth; Crops; decision support systems; dry matter accumulation; Evapotranspiration; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Greenhouse; Greenhouses; groundwater contamination; Irrigation; irrigation management; leaching; Management; Melon; microirrigation; model validation; muskmelons; nitrogen; Nitrogen uptake; photosynthetically active radiation; planting date; plastic greenhouses; production technology; radiation use efficiency; simulation models; Uptakes; vegetable growing; Water balance and requirements. Evapotranspiration; Model; Nitrogen uptake; Crop growth; Greenhouse; Evapotranspiration; Melon; Non metal; Plant production; Evaluation; Vegetals; Growth; Cucurbitaceae; Nitrogen; Nutrient uptake; Modeling; Group VA element; Fruit crop; Dicotyledones; Angiospermae; Water engineering; Spermatophyta; Models; Cucumis melo; Cultivated plant
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/j.agwat.2011.09.008

► The crop simulation model VegSyst was developed for muskmelon grown in plastic greenhouses. ► The model provided daily simulation of crop dry matter accumulation, N uptake and ET c. ► The model was calibrated using one crop and accurately validated with three different crops. ► The model was enhanced by using two RUE values, one each for vegetative and reproductive growth. ► The model is suitable for incorporation into a decision support system for daily N and water requirements. Like many intensive vegetable production systems, the greenhouse-based system on the south-eastern (SE) Mediterranean coast of Spain is associated with considerable NO 3 − contamination of groundwater. Drip irrigation and sophisticated fertigation systems provide the technical capacity for precise nutrient and irrigation management of soil-grown crops which would reduce NO 3 − leaching loss. The VegSyst crop simulation model was developed to simulate daily crop biomass production, N uptake and crop evapotranspiration (ET c). VegSyst is driven by thermal time and consequently is adaptable to different planting dates, different greenhouse cooling practices and differences in greenhouse design. It will be subsequently incorporated into a practical on-farm decision support system to enable growers to more effectively use the advanced technical capacity of this horticultural system for optimal N and irrigation management. VegSyst was calibrated and validated for muskmelon grown in Mediterranean plastic greenhouse in SE Spain using data of four melon crops, two grown in 2005 and two in 2006 using two management strategies of water and N management in each year. VegSyst very accurately simulated crop biomass production and accurately simulated crop N uptake over time. Model performance in simulating dry matter production (DMP) over time was better using a double radiation use efficiency (RUE) approach (5.0 and 3.2 g MJ −1 PAR for vegetative and reproductive growth phases) compared to a single RUE approach (4.3 g MJ −1 PAR). The simulation of ET c over time, was very accurate in the two 2006 muskmelon crops and somewhat less so in the two 2005 crops. The error in the simulated final values, expressed as a percentage of final measured values was −1 to 6% for DMP, 2–11% for crop N uptake, and −11 to 6% for ET c. VegSyst provided effective simulation of DMP, N uptake and ET c for crops with different planting dates. This model can be readily adapted to other crops.