AquaCrop: A new model for crop prediction under water deficit conditions

• Published in: Options Méditerranéennes. Série A : Séminaires Méditerranéens (CIHEAM) no. 80
• Main Authors: Steduto, P.; Izzi, G.; Hoogeveen, J., FAO, Rome (Italy). Land and Water Division, Raes, D., Leuven University, Leuven (Belgium). Department of Land Management and Economics, K.U, Hsiao, T.C., University of California, Davis (USA). Department of Land, Air and Water Resources, Fereres, E., University of Cordoba, (Spain), Heng, L., Joint FAO-IAEA Programme of Nuclear Techniques in Food and Agriculture, Vienna (Austria)
• Format: Journal Article
• Language: English
• Published: Zaragoza (Spain) CIHEAM-IAMZ 2008
• Subjects: AGUA; CROPS; CULTIVOS; DROUGHT; EAU; http://www.fao.org/aos/agrovoc#c_1972; http://www.fao.org/aos/agrovoc#c_2391; http://www.fao.org/aos/agrovoc#c_24242; http://www.fao.org/aos/agrovoc#c_6210; http://www.fao.org/aos/agrovoc#c_8309; http://www.fao.org/aos/agrovoc#c_8488; MODELE DE SIMULATION; MODELOS DE SIMULACION; PLANTE DE CULTURE; PRODUCTIVIDAD; PRODUCTIVITE; PRODUCTIVITY; RENDEMENT; RENDIMIENTO; SECHERESSE; SEQUIA; SIMULATION MODELS; WATER; YIELDS
• ISBN: 9782853523905; 285352390X
• ISSN: 1016-121X

Estimating attainable yield under water-limiting conditions remains central in arid, semi-arid and drought-prone environments. To address this need, FAO has been developing a yield-response to water model, AquaCrop, which simulates attainable yields of the major herbaceous crops. As compared to other crop models, AquaCrop has a significantly smaller number of parameters and a better balance between simplicity, accuracy andr obustness. Root zone water content is simulated by keeping track of incoming and outgoing water fluxes at its boundaries, considering the soil as a water storage reservoir with different layers. Instead of leaf area index, AquaCrop uses canopy ground cover. Canopy development, stomatal conductance, canopy senescence and harvest index are the key physiological crop responses to water stress. Evapotranspiration is simulated as crop transpiration and soil evaporation and the daily transpiration is used to derive the daily biomass gain via the normalized biomass water productivity of the crop. The normalization is for reference evapotranspiration and CO2 concentration to make different water management systems, including rainfed agriculture and supplemental, deficit, and full irrigation. Simulations can be carried out both on calendar and thermal time, and the developing versions will incorporate effects of nutrient regimes, particularly nitrogen, and of soil salinity. AquaCrop is mainly addressed to extension services practitioners, consulting engineers, governmental agencies, NGOs and farmers associations.