slide1
Download
Skip this Video
Download Presentation
Calibration and Evaluation of Three CROPGRO Models under Different Water Regimes in a Semi-Arid Tropical Environment

Loading in 2 Seconds...

play fullscreen
1 / 32

Calibration and Evaluation of Three CROPGRO Models under ... - PowerPoint PPT Presentation


  • 463 Views
  • Uploaded on

Calibration and Evaluation of Three CROPGRO Models under Different Water Regimes in a Semi-Arid Tropical Environment. Kindie Tesfaye Haramaya University, Ethiopia 16 Dec 2008. Outline of presentation. Introduction Ethiopia Subject Methodology Results Conclusion. Introduction.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Calibration and Evaluation of Three CROPGRO Models under ...' - Sharon_Dale


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Calibration and Evaluation of Three CROPGRO Models under Different Water Regimes in a Semi-Arid Tropical Environment

Kindie Tesfaye

Haramaya University, Ethiopia

16 Dec 2008

outline of presentation
Outline of presentation
  • Introduction
    • Ethiopia
    • Subject
  • Methodology
  • Results
  • Conclusion
introduction
Introduction

The topic presented is result of research conducted in Ethiopia

Ethiopia is one of the ancient civilized countries

Has its own calendar (Julian) and Alphabets

Federal administration (14 states)

country profile
Country profile

Location: 8o 00 N, 38o 00 E

Area: 1.13 million sq km (437,794 sq miles)

Elevation: -125 to 4620 m

Population: 75 million (UN, 2007)

Capital:Addis Ababa

Major languages:Amharic, Oromo, Tigrinya, Somali, English (schools)

Major religions:Christianity, Islam

Main exports:Coffee, hides, cereals, oilseeds, grain legumes, beeswax, sugar, cotton, cut flowers, livestock products

Natural recourses: reserves of gold, platinum, copper, potash, natural gas, petroleum, hydropower

Tourist attractions: National game reserves (parks), historical places, the oldest human fossils found (e.g. Lucy-3.18 m yrs old).

endemic animals and plants
Endemic Animals and Plants

23 endemic birds

Chilada Baboon

Walia Ibex

Red fox

Mountain Nyala

Colobus Monkey

Oryx Spps.

Many plant genetic resources

country profile historical places
Country profile-historical places

Blue Nile Water Falls

Negash Mosque- 2000 yrs old

Sofamar Natural cave

Axum Stelle- > 2000 yrs old

Lalibela rock hewn churches-built in the 12th C.

Axum Zion- the oldest church

Fasilede Palace –built in 16th C

challenges
Challenges

Climate variability

Recurrent drought

Crop failures

Deforestation

Soil Degradation

challenges9
Challenges…
  • Almost half of the country is in the semi-arid climate belt
  • Agricultural decision making is difficult
    • Climate variability
    • Climate change
    • Poor research and extension coverage
    • lack of interdisciplinary approach
  • Grain legumes (drybean, chickpea, cowpea) are relegated to marginal areas
      • the majority of the production of these crops comes from the semi-arid parts of the country
slide10

Crop models could play an important role in managing agricultural production in the these areas because:

    • Involve integrated approach (climate, soil, crop, management) at once
    • fast results
    • Inexpensive
slide11

The CSM-CROPGRO model has been used to study and evaluate several production problems including:

      • climate change (e.g. Mera et al., 2006; Challinor and Wheeler, 2008)
      • spatial yield variability (Paz et al., 2001)
      • water related constraints (e.g. Ruiz-Noueira et al., 2001)
      • plating date and cultivar selection ( Cooper et al., 2006)
      • plant population and fertilizer interactions (Meirles et al., 2002)
      • optimum irrigation optimization (Faria et al., 1997; Heinemann et al., 2000).
objective
Objective

To calibrate and evaluate CROPGRO-drybean, chickpea and cowpea under three water regimes in a semi-arid tropical environment

methodology
Methodology
  • Site: Dire Dawa
      • latitude 9o6’N
      • longitude 41o8’ E
      • altitude 1197 m
  • Season: Three seaosns
      • Dec, 2001-March, 2002
      • April-July, 2002
      • Oct, 2002-March, 2003
  • Treatments: Three water regimes
      • Well-irrigated control (C)
      • Mid-season water deficit (MS)
      • Late-season water deficit (LS)
      • Three crops (drybean, chickpea, cowpea)
  • Design: Split-plot in RCBD (WR: main plot;
      • Water regimes: main-plot; Crops: sub-plot
data collection
Data collection
  • Phenology
  • Growth, Yield & YC
  • Soil water
  • Physiology (PS, SC, LWP)
  • Canopy and soil temp.
  • Radiation interception
  • Weather
  • Soil (initial, profile)
  • Crop management
methodology15
Methodology…
  • Data organization for DSSAT format
    • data were organized and all the required files created (Soil.Soil, WTH files, Xfiles, A files, T files)
  • Calibration
    • the 2001/2003 well-irrigated treatment of the respective spps.
    • Stepwise calibration followed
      • First phenological parameters using Gencalc
      • Growth and yield: sensitivity analysis using the data in the Tfiles
  • Evaluation
    • Comparing simulated and measured phenology, growth and yield parameters with using
      • RMSE
      • MAD
      • CV (%)
      • Willmot’s Index of agreement (d)
      • Coefficient of determination (R2)
results calibration
Results-Calibration

Table 1. Calibrated genetic coefficients of drybean, chickpea, cowpea using data from a well-irrigated experiment

results model evaluation22
Results-Model Evaluation…

2. Days to flowering (dap)

results model evaluation23
Results-Model Evaluation…

3. Physiological maturity

results model evaluation25
Results-Model Evaluation…

4. Growth-chickpea

results model evaluation27
Results-Model Evaluation…

4. Grain yield (kg ha-1)

results model evaluation28
Results-Model Evaluation…

5. Relative yield reduction

results model evaluation29
Results-Model Evaluation…

5. Simulated WSF vs. Measured LWP

conclusion
Conclusion
  • The CSM-CROPGRO- drybean, chickpea and cowpea models accurately simulated:
      • soil water dynamics in the root zone layer and the duration and intensity of water deficit occurrence during the growing seasons
      • the seasonal pattern of LAI, biomass accumulation and pod growth under different water regimes although accuracy is less in the MS treatment, and
      • grain yield variability with water supply.
  • The models overestimated the duration of physiological maturity under water deficit conditions suggesting the need for further improvement in this regard.
conclusion31
Conclusion…
  • If properly calibrated, the models have shown their ability to be used as decision support tools in:
      • irrigation water management,
      • choice of cultivars to different water supply environments,
      • prescreening of genotypes for drought tolerance and
      • determining the occurrence and severity of agricultural drought in the semi-arid tropical environments.
ad