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Titolo:
A SIMULATION-MODEL OF THE WHEAT CROP IN RESPONSE TO WATER AND NITROGEN SUPPLY .2. MODEL VALIDATION
Autore:
OLEARY GJ; CONNOR DJ;
Indirizzi:
VICTORIAN INST DRYLAND AGR,PB 260 HORSHAM VIC 3400 AUSTRALIA UNIV MELBOURNE,DEPT AGR,JOINT CTR CROP IMPROVEMENT PARKVILLE VIC 3052AUSTRALIA
Titolo Testata:
Agricultural systems
fascicolo: 1, volume: 52, anno: 1996,
pagine: 31 - 55
SICI:
0308-521X(1996)52:1<31:ASOTWC>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
MEDITERRANEAN-TYPE ENVIRONMENT; VICTORIAN MALLEE; SPRING WHEAT; GRAIN-YIELD; SOLAR-RADIATION; GROWTH; TEMPERATURE; CULTIVARS; ANTHESIS; ECONOMY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
60
Recensione:
Indirizzi per estratti:
Citazione:
G.J. Oleary e D.J. Connor, "A SIMULATION-MODEL OF THE WHEAT CROP IN RESPONSE TO WATER AND NITROGEN SUPPLY .2. MODEL VALIDATION", Agricultural systems, 52(1), 1996, pp. 31-55

Abstract

The simulation model of soil water, mineral nitrogen supply and crop response of the wheat crop described in Part I was validated against field data from two semi-arid sites in northwest Victoria, Australia, over a period of 4 yr. The experimental data consisted of the four fallow combinations of stubble retention and zero tillage plus a tilled summer fallow prior to pea and wheat crops in rotation. Total soil waterwas simulated well (R(2) = 0.95; RMSE = 0.02 Mg/m(3)) with a generally good characterization of the soil water profile. Some under-estimation of water content occurred at depth during the final crop growth stage as a consequence of over-estimation crop growth and water use. Total soil mineral nitrogen (SMN) was stimulated with less accuracy than soil water (R(2) = 0.61; RMSE = 1.84 g/m(3)). Although the simulation of surface (0 - 10 cm) SMN was generally poorer, the model gave a good account of SMN at depth that ensures good simulation of nitrogen uptake late in the growing season when nitrogen responses are important to crop yield. The stimulation of biomass clearly followed the general pattern observed throughout the season (R(2) = 0.77; RMSE = 1655 kg/ha) with final biomass closely matching the observed data in most years. Grain yield was simulated with less accuracy than biomass (R(2) = 0.42;RMSE = 756 kg/ha). This was largely because grain number was poorly simulated (R(2) = 0.07; RMSE = 1425 m(-2)) and when observed grain number was used in the model the accuracy of yield was increased (R(2) = 0.59; RMSE = 615 kg/ha). Simulated grain size (R(2) = 0.61; RMSE = 5.6 mg) was more accurate than grain nitrogen concentration (R(2) = 0.29; RMSE = 0.31% N). Seasonal crop water use was simulated well (R(2) - 0.83; RMSE = 34 mm). There was no evidence of bias between the various tillage methods tested in the simulations with respect to the soil water and nitrogen and crop response. Copyright (C) 1996 Elsevier Science Ltd

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 23/11/20 alle ore 21:47:41