Iran Iran

Iran is the world's 18th-most-populous country with about 81 million inhabitants. With a land area of 1,648,195 km2, Iran is the 17-th largest in the world.  The country lies between latitudes 24° and 40° N, and longitudes 44° and 64° E in the southeast of Asia. Almost 60 percent of the country is dominated by mountainous area, and the rest consists of deserts and arid lands. Iran includes two major mountain systems, named Alborz and Zagros (Fig. 1). These mountain ridges which run east and southeast from the northwest corner of the country, surrounding two uninhabited deserts, Dasht-e Lut and Dasht-e Kavir.  

 

Fig. 1. Topography of Iran (from Wikimedia).

Land and cultivation

Total cultivated area has been fluctuating around 12 million ha over the past 25 years (Mesgaran et al., 2016). Distribution of agricultural area between different plant groups is indicated in Table 1 which is based on data from 2011 to 2016. It should be noted that figures in Table 1 do not indicate physical area under cultivation because where double cropping has been practiced, the land area under both the first and the second crop has been summed up. Total cultivated area by crops, orchards and vegetables is 14,448,101 ha, irrigated area is 8,447,010 ha (58%) and rainfed area is 6,001,091 ha (42%). Crop production takes place on 11,319,360 ha of which is 5,695,046 ha is irrigated (50%) and 5,624,314 ha is rainfed.

Table 1. Distribution of cultivated land (ha) between different plant groups and irrigated and rainfed systems. Where double cropping is practiced, the land under the first and the second crop has been summed up. Greenhouse area is 5,864 ha.

 

Category

Irrigated

Rainfed

Sum

Crop

5,695,046

5,624,314

11,319,360

Orchard

2,221,803

334,633

2,556,436

Vegetable

530,162

42,144

572,306

Sum

8,447,011

6,001,091

14,448,102

 

Table 2 includes area, production and average yield of different crops in Iran. Crops covered by GYGA-Iran are marked by asterisk. Of the covered crops, wheat, barley, rapeseed are grown as both irrigated and rainfed. More than 90% of chickpea and lentil are produced under rainfed conditions, while alfalfa, rice, maize (for grain and silage), potato, common bean, sugar beet, cotton and soybean are mainly grown under irrigated conditions in the country.

 

Table 2. Area, production and average yield of different crops of Iran using 2011-2016 data from Ministry of Agriculture.

Crop

Area (ha)

Production (million ton)

Yield (kg/ha)

Wheat*

6,170,164

10.65

1730

Barley*

1,680,021

2.98

1779

Alfalfa*

620,985

5.46

8851

Rice*

555,014

2.30

4269

Chickpea*

470,265

0.21

457

Grain maize*

242,821

1.67

6897

Silage maize*

183,244

9.14

50800

Potato*

164,110

4.87

30050

Lentil*

134,574

0.07

537

Common bean*

116,095

0.22

1876

Sugar beet*

102,885

4.86

47449

Cotton*

91,670

0.20

2219

Sugarcane

83,579

6.52

78004

Sunflower

74,010

0.11

1553

Rapeseed*

73,771

0.12

1684

Soybean*

64,905

0.14

2213

Clover

61,090

0.83

15012

Sesame

59,033

0.05

875

Other Crops

371,125

9.10

25233

*Covered by GYGA-Iran so far.

Climate

Spatial distribution of annual precipitation and air temperature are presented in Fig. 2 and 3. Fig. 4 presents climate zones of Iran based on GYGA-ED climate classification method.

Fig 2. Spatial distribution of precipitation in Iran (1961–2005); only major isohyets map is shown (Khalili and Rahimi, 2018).

Fig. 3. Spatial distribution of mean annual air temperature over Iran (1961–2005) (Khalili and Rahimi, 2018).

 

Fig. 4. Climate classification of Iran using GYGA-ED method (van Wart et al., 2013).

Examining GYGA-ED climate zone classification for Iran reveals that there are 72 climate zones in the country and agriculture is practiced in 68 climate zones. Thus, the diversity of climates is very high. Irrigated land mainly occurs in 15 climate zones and  more than 50% of irrigated lands are in climate zones 5003, 4003, 5002, 8003 and 6003 (Fig. 5). Therefore, irrigated agriculture is performed in dry climates with a high temperature fluctuation. Rainfed agriculture is located in 19 climates zones, but more than 50% of rainfed area is located in climate zones 4103, 4003 and 3103, i.e. relatively cold climates (Fig. 5).

Fig. 5. Dominant climate zones with irrigated and rainfed land in Iran.

Selecting weather stations

Selection of reference weather stations (RWS) and buffer zones for each crop was based on GYGA protocol as described by Van Wart et al. (2013) and van Bussel et al. (2015). The number of climate zones, percentage coverage (based on climate zone) and the number of RWSs for each crop are shown in Table 3. Weather data were quality checked for extreme or missing values and unusual changes using WeatherMan utility of DSSAT (Jones et al., 2003). Solar radiation data for all RWSs were calculated from sunshine hours using this utility software. For 23 weather stations, it was needed to generate few years of weather to have a complete data set for simulation of potential yield (Appendix I), which was again performed using WeatherMan. Generated weather consisted 6.5% of all weather data used. This percentage was different for each crop, but was never more than 10% for a single crop.

So far, weather data from 133 weather stations across the country were used for the selected crops (Fig. 6; Appendix I). Besides one station, all other stations were synoptic weather stations. Of the 133 weather stations, 19 are hypothetical. All the hypothetical stations are ‘first preference' type as defined by GYGA protocol, i.e., they are existing weather stations with good quality data (>20 years) as close as possible to the hypothetical RWS and within the same climate zone.

Fig. 6. Reference weather stations selected for GYGA-Iran.

 

Table 3. Total area, percentage coverage (within the climate zones), the number of climate zones (CZ) and the number of reference weather stations (RWS) for different crops in GYGA-Iran.

Crop

Area (ha)

Coverage (%)

#CZ

#RWS

Irrigated wheat

2,242,475

90.5

15

29

Rainfed wheat

3,692,938

89.7

18

32

Irrigated barley

734,993

89.6

12

48

Rainfed barley

1,036,931

87.9

17

38

Irrigated rice

559,632

88.1

14

21

Rainfed chickpea

492,202

91.1

11

20

Irrigated maize

198,206

91.0

13

23

Irrigated potato

164,439

94.0

15

35

Irrigated bean

114,593

92.5

12

25

Irrigated sugar beet

110,631

92.7

13

28

Irrigated cotton

76,217

97.2

9

23

Irrigated rapeseed

44,496

92.4

16

22

Rainfed rapeseed

16,963

93.5

12

21

Irrigated soybean

57,462

90.1

9

9

 

Soil data

Soil information is a key input to the models for potential yield estimation under rainfed conditions, yet it is difficult to obtain extensive, quantitative, and geo-referenced soil property data for the areas (or regions) of interest. Generic/Prototypical Soil Profiles from HarvestChoice (http://droppr.org/data/map/hc27) which itself is based on information from HWSD and WISE were used (Koo and Dimes, 2010). HC27 already contains 27 soil profiles. The soil profiles in HC27 are based on three criteria that crop models are most responding to, i.e. (i) texture, (ii) rooting depth, and (iii) organic carbon content. By classifying three levels for each category and setting their boundary conditions, Koo and Dimes (2010) generated 27 generic soil profiles (HC27) in formats compatible with DSSAT and APSIM (we didn't derive/create the profiles). The profiles include curve number for calculation of run-off. There was a good agreement between soil texture from HC27 and local, point observations of soil texture.

Fig. 7. Soil map of Iran (Koo and Dimes, 2010). 

 

Evaluation of the HC27 soil map and the map of Iran agricultural lands showed that 9 soil profiles are dominant in Iran. In irrigated lands, dominant soil profiles are Soil #5 (clay with medium fertility and a depth of 120 cm) and Soil #17 (loam with low fertility with a depth of 120 cm) (Fig. 8). In rainfed lands, these are Soil #5 (clay with medium fertility and a depth of 120 cm) and Soil #12 (loam, high fertility with a depth of 60 cm) (Fig. 8). Table 4 includes main characteristics of the dominant soils.

 

Fig. 8. Dominant soil profiles in irrigated and rainfed land of Iran.

Table 4. Prevalent soil profiles and their characteristics in cultivated area of investigated crops in GYGA-Iran based on HC27 soil map of Koo and Dimes (2010). SOC is soil organic carbon (%), SOLDEP is soil depth (mm), SALB is soil albedo, DRAINF is soil drainage factor, SAT is soil water content at saturation (m3 m-3), DUL is soil water content at drained upper limit (m3 m-3), and LL is soil water content at lower limit (m3 m-3).

Soil profile

SOC

SOLDEP

SALB

CN

DRAINF

SAT

DUL

LL

HC2-Clay HF120

>1.2

1200

0.05

85

0.2

0.46

0.40

0.23

HC5-Clay MF120

0.7-1.2

1200

0.05

85

0.2

0.46

0.40

0.23

HC8-Clay LF120

0-0.7

1200

0.05

85

0.2

0.46

0.40

0.23

HC12-Loam HF060

>1.2

600

0.10

75

0.5

0.41

0.30

0.18

HC14-Loam MF120

0.7-1.2

1200

0.10

75

0.5

0.41

0.30

0.18

HC17-Loam LF120

0-0.7

1200

0.10

75

0.5

0.41

0.30

0.18

 

Soil codes (IFPRI Harvest Choice): 2=Clay, high fertility, 120 cm depth; 5=Clay, medium fertility, 120 cm depth; 8=Clay, low fertility, 120 cm depth; 12=Loam, high fertility, 60 cm depth; 14=Loam, medium fertility, 120cm depth; 17=Loam, low fertility 120 cm depth.

 

Crop area maps, harvested area and actual yields

The main source for distribution of harvested area in GYGA is SPAM crop distribution maps. However, in GYGA-Iran specific maps were generated for crops under analysis as we found that SPAM maps were not accurate at least for some crops. To do this, data of harvested area were obtained from more than 400 counties over the country from the Ministry of Agriculture. Maps with crop area distribution of each crop were generated using crop area at each county and distribution of irrigated or rainfed lands of Iran. Uniform crop distribution was assumed at county level if a crop is grown in that county. Fig. 9 compares crop area map for potato obtained in GYGA-Iran with that of SPAM2005, as an example.

 

 

Fig. 9. SPAM2005 crop area map for potato in Iran (above) and revised potato area map prepared for GYGA-Iran (below).

 

Data of harvested area, production and yield of crops were obtained from the Ministry of Agriculture for the period of 2001-2015, but crop distribution maps were prepared using 2014 to 2016 data. Actual yield for each buffer was calculated as weighted average where weights were county areas in the buffer.  

Cropping system and crop management information

Cropping systems in Iran are wheat or rice based. Wheat based systems can be seen all over the country, but rice based systems are mainly found in the north (Caspian Sea coast) and in some other patchy areas in the country. Depending on temperature, single or double cropping is practiced. In warmer climates with mild winter, double cropping using wheat or rice is dominant, but in regions with cold winters ‘one-crop-per-year' system is used, so that wheat or rice are grown alone or in sequence (rotations) with other crops.

Typical crop management information was gathered from local experts with the help of Agricultural Research, Education and Extension Organization (AREEO) centers and institutes all over the country. Actual yield and potential yield were also items in the questionnaires. For GYGA simulations, typical planting and harvesting dates were used, but for other management factors (e.g. planting density) optimal values were used.

Crop simulation

SSM crop models were used for the simulation of potential yields (Yp, Yw). The models are based on T.R. Sinclair's approach in crop modeling. The history of the model development goes back to the 1970s (Sinclair and de Wit, 1976). The models have been developed and tested for wheat, barley, chickpea, lentil, common bean, peanut, cowpea, maize and sorghum (Sinclair, 1986; Amir and Sinclair, 1991; Hammer et al., 1995; Soltani and Sinclair, 2011; Soltani et al., 2013) during the past 40 years. Soltani and Sinclair (2012) presented principles and procedures in developing SSM models.

Not all above mentioned evaluation results refer to Iran's conditions. Thus, for GYGA-Iran, we parameterized and tested the models for all crops using data from Iran. For this purpose, experimental data from major producing areas of these crops in Iran were collected. The data were divided into two parts, one part for model parameterization and the other part for independent model testing. Furthermore, potential yield data from the major producing areas were separately used for model testing for potential yield. Appendix II includes evaluation results for selected crops in GYGA-Iran.

 

Disclaimer

GYGA-Iran was conducted with the support from Gorgan University of Agricultural Sciences and Natural Resource (GUASNR) and Agricultural Research, Education and Extension Organization (AREEO) of Ministry of Agriculture.

 

References

Amir, J., Sinclair, T.R., 1991. A model of water limitation on spring wheat growth and yield. Field Crops Res. 29, 59-69.

Hammer, G.L., Sinclair, T.R., Boote, K.J., Wright, G.C., Meinke, H., Bell, M.J., 1995. A peanut simulation model: I. Model development and testing. Agron. J. 87: 1085-1093.

Jones, J.W., Hoogenboom, G., Porter, C.H., Boote, K.J., Batchelor, W.D., Hunt, L.A., Wilkens, P.W., Singh, U., Gijsman, A.J., Ritchie, J.T., 2003. The DSSAT cropping system model. Eur. J. Agron. 18, 235-265.

Khalili, A., Rahimi, J., 2018. Climate BT  - The Soils of Iran, in: Roozitalab, M.H., Siadat, H., Farshad, A. (Eds.), . Springer International Publishing, Cham, pp. 19–33.

Koo, J., and Dimes, J. 2010. HC27 Generic Soil Profile Database. Version 1, July. International Food Policy Research Institute, Washington, DC.

Mesgaran, M., Madani, K., Hashemi, H., Azadi, P., 2016. Evaluation of land and precipitation for agriculture in Iran. Working paper #2, Iran 2040 Project, Stanford University.

Sinclair, T.R., 1986. Water and nitrogen limitations in soybean grain production: Model development. Field Crops Res. 15: 125-141.

Sinclair, T.R., de Wit, C.T., 1976. Analysis of the carbon and nitrogen limitations to soybean yield. Agron. J. 68, 319-324.

Soltani, A., Sinclair, T.R., 2011. A simple model for chickpea development, growth and yield. Field Crops Research 124 (2011) 252–260.

Soltani, A., Sinclair, T.R. 2012. Modeling Physiology of Crop Development, Growth and Yield. CABI publication. 322 p.

Soltani, A., Maddah, V., Sinclair, T.R., 2013. SSM-Wheat: a simulation model for wheat development, growth and yield. Int. J. Plant Prod. 7(4): 711-740.

van Bussel, L.G., Grassini, P., Van Wart, J., Wolf, J., Claessens, L., Yang, H., Boogaard,H., de Groot, H., Saito, K., Cassman, K.G., van Ittersum, M.K., 2015. From field toatlas: upscaling of location-specific yield gap estimates. Field Crop Res. 177,98–108.

van Wart, J., van Bussel, L. G. J., Wolf, J., Licker, R., Grassini, P., Nelson, A., Boogaard, H., Gerber, J., Mueller, N. D., Claessens, L., van Ittersum, M. K., and Cassman, K. G. 2013. Use of agro-climatic zones to upscale simulated crop yield potential. Field Crops. Res. 143:44-55.

Appendix I. List of weather stations Appendix I. List of weather stations

 

NAME

#WMO

LAT

LONG

ELV

Real data

Genarated data

ABADAN

40831

30.38

48.21

7

1999-2016

 

ABADEH

40818

31.20

52.62

2030

1960-2016

 

ABALI

40755

35.75

51.88

2465

1960-2016

 

AGHTOGHE

37.90

55.63

250

   

AHMADABAD (HYP)

 

29.56

52.60

1488

   

AHWAZ

40811

31.34

48.74

23

1960-2016

 

ALIABAD

99300

36.90

54.88

184

2004-2016

1999-2003

ALIGOODARZ

40783

33.41

49.70

2022

1986-2016

 

ALIGOODARZ (HYP)

 

33.65

49.58

2000

   

ARDABIL

40708

38.22

48.33

1335

1976-2016

 

AVAJ

99310

35.57

49.22

2035

1997-2016

 

BAM

40854

29.10

58.35

1067

1960-2016

 

BANDARAMIRABAD

99306

36.86

53.39

-20

2004-2016

1999-2003

BANDARANZALI

40718

37.48

49.46

-24

1960-2016

 

BANEH

99280

36.01

45.90

1600

1960-2016

 

BAVANAT

99561

30.48

53.61

2231

1960-2016

 

BEHBAHAN

40834

30.61

50.22

313

1993-2016

 

BIARJAMAND

40742

36.09

55.81

1099

1992-2016

 

BIJAR

40748

35.89

47.62

1883

1987-2016

 

BILESOWAR

99202

39.37

48.32

101

2004-2016

1999-2003

BIRJAND

40809

32.89

59.28

1491

1960-2016

 

BOROOJEN

99459

31.98

51.30

2260

1988-2016

 

BOSHROOYEH

99407

33.87

57.43

879

1988-2016

 

BOSTANABAD

99248

37.85

46.84

1736

2006-2016

1999-2005

BROUJERD

40774

33.92

48.76

1629

1988-2016

 

CHAHCHAHEH (HYP)

 

36.50

60.33

500

   

DARAN

40787

32.97

50.37

2290

1993-2016

 

DEHLORAN

40796

32.68

47.28

232

1990-2016

 

DEZFUL (SAFIABAD)

40794

32.25

48.43

83

1987-2016

 

DOGONBADAN

40835

30.35

50.82

726

1985-2016

 

DORODZAN

40844

30.21

52.42

1642

1988-2016

 

DOROUD

99444

33.52

49.00

1522

2000-2016

 

EDAREGORGAN

40738

36.91

54.41

0

1960-2016

 

EGHLIDEFARS

40828

30.90

52.63

2300

1995-2016

 

ESLAMABADGHARB

40779

34.12

46.47

1349

1988-2016

 

FARIMAN

40825

35.65

59.83

1472

2008-2016

1999-2007

GALANDROOD (HYP)

 

36.45

53.90

1294

   

GALIKESH-KALALEH (HYP)

 

36.95

56.33

984

   

GARMSAR

40758

35.24

52.36

900

1986-2016

 

GERMI

40714

39.05

48.06

749

2004-2016

1999-2003

GHARAKHILGHAEMSHR

40737

36.45

52.77

15

1984-2016

 

GHARGHABAD

99412

35.11

49.83

1590

2006-2016

1999-2005

GHAZVIN

40731

36.26

50.06

1279

1960-2016

 

GHOM

40770

34.77

50.86

879

1960-2016

 

GHOOCHAN

40740

37.12

58.45

1287

1984-2016

 

GHORVEH

40772

35.18

47.79

1906

1989-2016

 

GONBAD

99240

37.27

55.21

37

1992-2016

 

HAJIABAD (SOUTH KHORASAN) (HYP)

 

33.63

59.92

1447

   

HAJIABAD HORMOZGAN

40863

28.31

55.91

931

1998-2016

 

HAJIARAB (HYP)

 

35.11

49.83

1590

   

HAMEDAN (AIRPORT)

40768

34.87

48.53

1741

1992-2016

 

HASANABADEDARAB

40862

28.79

54.30

1098

1995-2016

 

HASHMABAD

99241

36.85

54.27

13

1985-2015

 

HEZARKANIAN (HYP)

 

35.75

46.80

1934

   

ILAM

40780

33.59

46.40

1337

1986-2016

 

IZEH

99455

31.85

49.85

767

1993-2016

 

JAHROM

99646

28.48

53.53

1082

2006-2016

1999-2005

JAJARM

99295

36.95

56.33

984

2005-2016

1999-2004

KABOOTARABAD

40803

32.52

51.83

1543

1987-2016

 

KAHNOUJ

40877

27.99

57.71

499

1990-2016

 

KARAJ

40752

35.81

50.95

1293

1985-2016

 

KAREHSANG (HYP)

 

36.27

52.37

220

   

KASHAN

40785

33.97

51.48

955

1966-2016

 

KASHMAR

40763

35.27

58.47

1110

1986-2016

 

KERMAN

40841

30.26

56.96

1754

1960-2016

 

KERMANSHAH

40766

34.35

47.15

1319

1960-2016

 

KHAF (HYP)

 

34.58

60.15

998

   

KHASH

40870

28.23

61.19

1427

1986-2016

 

KHODABANDEH

40733

36.14

48.59

1887

1994-2016

 

KHORRAMABAD

40782

33.44

48.28

1148

1960-2016

 

KHORRAMDAREH

40730

36.20

49.21

1575

1986-2016

 

KIASAR

40760

36.25

53.55

1294

2002-2016

1999-2001

KOMIJAN

99432

34.71

49.31

1741

2005-2016

1999-2004

KOOHDASHT

99438

33.52

47.65

1198

1997-2016

 

KOOHRANG

40797

32.46

50.13

2365

1987-2016

 

LALEHZAR

40852

29.52

56.83

2775

2003-2016

2000-2002

LAR

40873

27.67

54.37

792

1989-2016

 

LORDEGAN

40814

31.50

50.83

1611

1995-5016

 

LOUMAR

99463

33.56

46.83

850

2008-2016

1999-2007

MAHABAD

40726

36.75

45.72

1352

1985-2016

 

MAHNESHAN

40715

36.74

47.68

1285

2002-2016

1999-2001

MANEVASAMALGHAN

99262

37.51

56.86

890

2005-2016

1999-2004

MARAGHEH

40713

37.35

46.15

1344

1983-2016

 

MARAVETAPEH

40721

37.80

55.94

460

1993-2016

 

MARVAST

40840

30.40

54.20

1547

1997-2016

 

MASHHAD

40745

36.24

59.63

999

1960-2016

 

MASJEDSOLEYMAN

40812

31.98

49.24

321

1985-2016

 

MAZINAN (HYP)

 

36.32

56.80

820

   

MEIMEH (HYP)

 

33.43

51.16

1980

   

MESHKINSHAHR

40705

38.38

47.68

1561

1995-2016

 

MIANDEHJIROFT

40866

28.58

57.80

601

1989-2016

 

MIANEH

40716

37.45

47.70

1110

1987-2016

 

MINODASHT

99237

37.37

55.63

223

1985-2016

 

NAHAVAND

99384

34.14

48.41

1678

1996-2016

 

OMIDIYEH (PAYGAH)

40830

30.83

49.55

35

1993-2013

2014-2016

OROMIYEH

40712

37.66

45.06

1328

1960-2016

 

OSHNAVIEH

99288

37.06

45.14

1416

2006-2016

1999-2005

PARSABAD

40700

39.60

47.78

73

1984-2016

 

PASHAKOLA (HYP)

 

36.23

52.78

212

   

PIRANSHAHR

40724

36.70

45.15

1444

1986-2016

 

POLDOKHTAR

40786

33.15

47.72

714

1998-2016

 

POLSEFID

99360

36.13

53.08

610

2003-2016

1999-2003

RAMSAR

40732

36.90

50.68

-20

1960-2016

 

RASHT

40719

37.20

49.62

25

1960-2016

 

RAVANSAR

40764

34.72

46.65

1380

1988-2016

 

ROSTAMROOD (HYP)

 

36.58

52.10

0

   

RUDAN

99656

27.45

57.19

220

2003-2016

1999-2002

SABZEVAR

40743

36.21

57.65

962

1960-2016

 

SAGHEZ

40727

36.22

46.31

1523

1961-2016

 

SARAKHS

40741

36.54

61.15

278

1984-2016

 

SAREYN

99231

38.15

48.08

1658

2003-2016

1999-2002

SARGHANAT (HYP)

 

29.47

51.27

95

   

SARI

40759

36.54

52.99

23

1999-2016

 

SARPOLZAHAB

40765

34.45

45.87

545

1986-2016

 

SAVEH

99372

35.08

50.37

1112

1993-2016

 

SHAHMIRZAD

99386

35.77

53.35

1969

2010-2016

1999-2009

SHAHREKORD

40798

32.29

50.84

2049

1960-2016

 

SHAHREZA

40815

31.98

51.81

1858

1993-2016

 

SHAHROUD

40739

36.38

54.93

1325

1960-2016

 

SHAHROUD (HYP)

 

36.38

54.93

1325

   

SHIRAZ

40848

29.56

52.60

1488

1960-2016

 

SHIRINABAD (HYP)

 

36.72

55.02

1945

   

SISAKHT (HYP)

 

30.84

51.47

2133

   

SONGHOR

99429

34.78

47.58

1700

2006-2016

1999-2005

TABRIZ

40706

38.12

46.24

1361

1960-2016

 

TAKAB

40728

36.40

47.10

1817

1985-2016

 

TAKHTEJAMSHEID

99575

29.92

52.89

1605

2003-2016

1999-2002

TALESH

99249

37.84

48.90

7

   

TALKHBAKHSH (HYP)

 

35.72

58.87

1310

   

TORBATE JAM

40806

35.29

60.56

950

1993-2016

 

YASOUJ

40836

30.70

51.56

1816

1987-2016

 

ZABOL

40829

31.09

61.54

489

1980-2016

 

ZARGHAN

40847

29.78

52.70

1596

1989-2016

 

Appendix II. Model testing results Appendix II. Model testing results

It should be noted that data used in (A) and (B) panels are from different experimental treatments under both rainfed and irrigated conditions of main producing areas of that crop in Iran and are not necessary potential yield.

Wheat:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported irrigated potential yield (C), simulated versus observed cumulative irrigation water or evapotranspiration (D) and simulated potential yield versus reported rainfed potential yield. 

 

Barley:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported potential yield (C). In (C), potential yields reported for different locations are compared with minimum, average and maximum potential yield for the same locations over 15 years.

Rice:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported irrigated potential yield (C), simulated versus observed cumulative irrigation water (D).

High yield: new high yield cultivars

Low yield: local low yield cultivars  

Maize:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), and simulated potential yield versus reported irrigated potential yield (C).  In (C), potential yields reported for different locations are compared with minimum, average and maximum potential yield for the same locations over 15 years.

Chickpea:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported rainfed  potential yield (C).  In (C), potential yields reported for different locations are compared with minimum, average and maximum potential yield for the same locations over 15 years.

Common bean:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported potential yield (C), simulated versus observed cumulative evapotranspiration (D). 

Soybean:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported potential yield (C), simulated versus observed cumulative irrigation water (D). In (C), potential yields reported for three locations are compared with minimum, average and maximum potential yield for the same locations over 10 years.

Cotton:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported potential yield (C), and simulated versus observed cumulative irrigation water or evapotranspiration (D). In (C), potential yields reported for different locations are compared with minimum, average and maximum potential yield for the same locations over 14 years.

Rapeseed:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported irrigated potential yield (C), simulated versus observed cumulative irrigation water (D) and simulated potential yield versus reported rainfed potential yield (E).  

Potato:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported irrigated potential yield (C), and simulated versus observed cumulative irrigation water (D). 

Sugar beet:

Simulated versus observed yields from data used in model parameterization (A) and evaluation (B), simulated potential yield versus reported irrigated potential yield (C), and simulated versus observed cumulative irrigation water (D). 

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