ISSAAS jurnal

ISSAAS International Congress & General Meeting, Tokyo University of Agriculture, Japan, Nov. 8-10, 2014, ISSN 0859-3132

A COMPARISON OF THE CROP WATER REQUIRMENT FOR WHEAT AND TOMATO BETWEEN ACTUAL WIND CONDITION AND ZERO

WIND SIMULATION; WIND VELOCITY WITHIN 24-HOURS INTERVAL IN WESTERN AFGHANISTAN

Homayoon Ganji1 Abdul Saboor Rahmany1 Takamitsu Kajisa1 Masaaki Kondo1 Hajime Narioka1 Moheb Rahman Khademi2Ghulam Hazrat Qasemi2 and Aziz Ahmad Osmani2

1Graduate School of Bioresources, Mie University, 514-8507 Kurima-machiya-cho 1577, Tsu, Japan 2 Agriculture Irrigation and livestock Department, Urdo Khan Agricultural Research Station, Herat, Afghanistan

Abstract

Crop water requirement (ETc) and crop evapotranspiration are identical, kwon as the amount of water that needs to be supplied for all farming. Different agricultural types vary in water requirement amount in different region. ETc mainly depends on: the climate, the crop type and the crop growth stage as it is influenced by climate which is known as evapotranspiration (ET). In areas facing water scarcity, recognizing the factors that cause water losses is an important issue that should be taken into the consideration. The west part of Afghanistan, especially Herat and Farah provinces, is famous for having strong winds locally known as the “120-Day Winds” which persist from June until late September with a strong force. A great impact of wind velocity is increasing ET0 which can have profound implications for hydrologic processes and agricultural crop performance. This paper is aimed to; first, discover the velocity of wind during the daytime and nighttime in windy and non-windy seasons separately, including its influence on ET0 redaction, for proposing a better time for irrigation in a period of 24-hours interval. Second, comparing the ETc of three different types of wheat and tomato between actual condition and a simulated condition, in which the wind velocity is considered to be zero (ETcnwR). As the results, by measuring data of wind velocity for both windy and non-windy seasons from 2012, it has been found that, daytime wind velocity is higher than the nighttime, but its rate is two times lower during the nighttime in compare to the daytime especially in the windy season. Thus, nighttime is proposed as the proper time for irrigation in the west part of Afghanistan. Furthermore, wind velocity found the most influential factor on ET0, as ETwind found stronger than ETrad. On the other hand, by considering wind velocity zero as a simulated case (ET0nw), it is found two times lower than the actual case. Similarly, under the simulation case, ETc of three different types of wheat and tomato estimated based on measured data form 2006 to 2013, found much lower than the actual condition. Furthermore, the crops such as facultative wheat and tomato, which their growing seasons coincides in windy season, consumed more water than the spring and winter wheat.

Keywords: 120-day Winds, Irrigation scheduling, Evapotranspiration

INTRODUCTION

Crop water requirement (ETc) is kwon as the amount of water that needs to be supplied, as the values for crop evapotranspiration and ETc are identical (Allen, 1998). For all forms of farming, supply of water is an absolute essential, although different agricultural types varies in water requirement amount in different region (Morison et al,. 2008). The ETc mainly depends on: the climate, the crop type and the crop growth stage. ETc is influenced by climate which is known as evapotranspiration (ET0) (C. Brouwer et al., 1986). Water deficits in crops affect crop evapotranspiration and crop yield (Doorenbos, J. et al., 1979). Oweis et al, (2000) achieved the result that, the shortage of water limits wheat production.

In areas facing water scarcity, knowing the factors that cause water losses is an important issue that should be taken to the consideration. On the other hand, proper use of water for irrigation is possible through a good irrigation scheduling. The importance of irrigation scheduling is that it enables the irrigator to apply the exact amount of water

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in a right time to achieve the goal (Broner, 2005). This increases irrigation efficiency which is important in term of water shortage in the arid and semi-arid regions.

A critical element is accurate measurement of water lose and the volume of water applied or the depth of application, but another important factor especially in Herat province is the time of irrigation in regards of wind velocity at the windy season. Herat is characterized by a cold semi-arid climate, in which the average annual precipitation ranges from 152 to 214 mm; this precipitation is minimal and primarily occurs during winter and spring (AB. R Omid, 2009). The summer climate is temperate, especially in June and July when the maximum degree of hotness ranges from 38 °C to 43 °C; however, the climate throughout the remainder of the year is also reasonable (AFCCC, 2001). Three deferent types of wheat such as: winter wheat sown in October; facultative wheat, sown in December and spring wheat sown in February is produced in Herat province. Wheat is the main crop in Herat province, most of the rain feed and non-rained lands are planted wheat. Based on a survey in 2008, wheat as a major staple food made up almost 263,265 tons which cover 94% of all grains production in Herat province (USAID 2008). Tomato is one of the important agricultural products in Herat province which is sown in the late of May. There are more than ten deferent types of vegetables being cultivated, in which tomato has the first position in terms of volume. In 2008 tomato made up the largest volume (36,000 metric ton) and generating the highest profit (USAID 2008). Tomato farms are formed as furrow and greenhouses. In both methods, the main irrigation system is flood irrigation, whereas, drip irrigation can be found in greenhouses system only. So far, both irrigation and rain fed agricultural systems are practiced in Herat province. It was reported by Regional Rural Economic Regeneration Strategies (RRERS) project in 2008 that, the Northern districts are rain fed (approximately 90%) and central and eastern districts are mostly irrigated (more than 90 %). Major source of irrigation is Hirayrud River which irrigates more than 1000 ha of land. Other sources of irrigation are springs and karizes mainly in remote areas. The traditional old Mirab system still exists for regulation of water rights and operation of extensive irrigation infrastructures. There is two deferent planting seasons in Herat province including: Spring planting season and autumn planting season. Vegetables are mostly grown in spring season which continues till late summer and the autumn earlier, varies by crop types (RRERS 2008). The most critical time for irrigation is summer time, because most of planted crops reach in medal stage of growth that having high water demand and in other hand, this time is coincides with windy seasons, 120-day winds.

There in the west region of Afghanistan especially in Herat province, is a strong wind locally known as the 120-day winds, persists from June until end of September. The “120-day winds” adversely affects ET0, as it was confirmed that the ET0 is more than 10 mm/day (H Ganji et al., 2014).

Water shortage is one of the main problems in term of irrigation for agricultural activities in Herat provinces. In order to come over with this problem, it is felt to seek the best way for increasing water use efficiency. Therefore, in the previous research by H. Ganji et al. (2014), was confirmed that, wind velocity has profound influence on ET0.

In this paper, by estimating the hourly ET0 during the windy “120-day winds” and non-windy seasons, the best time (in a period of 24-hour interval) to irrigate will be scheduled and proposed for agricultural crops. In addition, ETc for three types of wheat (facultative wheat, winter wheat and spring wheat) including tomato will be measured and compered between windy and non-windy seasons through a simulation case at which wind velocity is considered zero (ET0nw), with aim to indicate wind velocity effect on ETc.

As it has already indicated, wind velocity is the most influential factor in term of ET0, the following hypothesized are made:

1- The wind velocity is higher during the daytime in compare of night time.

2- The highest amount of crops water requirement ETc is occurred in the windy season which is known as “120-day winds” locally.

3- In a simulation case at which wind velocity considered zero, the ET0 becomes small

MATERIAL AND METHOD

SiteThe only official center where is appropriate for researching, apart from Universities is Urdu khan Regional

Agricultural Research Station. This station is the largest station in the west region which was considered as study

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area in this research. Urdu khan research center with a total area of 225 hectares, located in a latitude of 39° 11' N and a longitude of 68° 13' E with an elevation of 964 meters in Urdu khan village, at 5.8 kilometers southeast of Herat city. The station is bounded by Urdu khan right canal on the north and east canal on the east. In 1968 approximately 15 hectares of the total area were cultivated for the first time and extended until now as a research center (Osmanzai, M. 2009).

According to the measured data of climatic factors from 2006 to 2013, daily average temperature was 17.8°C and the minimum temperature was -20°C, the average daily precipitation was around 0.68 mm, the daily average relative humidity is 37.7 % and the daily average wind speed is 294.0 km.

Metrological Data

Different sources are used for data collection Table 1. The metrological data is collected for year 2006 until 2013, which includes the daily sunshine hours, daily values of precipitation, maximum and minimum temperatures daily average humidity and daily average wind speed.

Mostly the climatic data is provided by Urdu Khan Research center where has not been equipped with standard and modern measurement devices yet. Furthermore, data missing is occurred sometimes as there were some missing data for some days within the targeted years. Thus, interpolation method is sued to cover missing data.

Basic Equations

In regards to the main purpose of this paper, water losses in consideration of ETc, has been estimated based on ET0. For estimation of daily and hourly ET0, Penman–Monteith method was used as it is a combination method with high accuracy. The Food and Agriculture Organization (FAO) has proposed a standardization of this method, which is known as the FAO-56 Penman–Monteith application. Both ET0 and ETc, is given in mm based on time according to Eq. (1) and Eq. (5).

The main requirements for calculating the evapotranspiration ET0 is solar radiation; air temperature, humidity, and a wind function [3].

ET 0 = ET rad + ET wind [1]

ET rad= 0.408 ∆ ¿{∆+γ (1+0.34 U2 )} [2]

ET wind=γ 900T +273

U 2d E ÷ {∆+γ (1+0.34 U 2) } [3]

d E = es−ea [4]

Where ET 0 is the reference crop evapotranspiration (mm/day), ET wind is a wind term (mm/day),ET rad is a radiation

term (mm/day), ∆ is the slope of the saturated air vapor pressure curve (kPa/°C), Rn is the net solar radiation at the crop surface (NJ/m2 day), G is the soil heat flux density (MJ/m2 day) as considered zero in in this calculation, γ is the psychometrics constant (kPa/℃), 0.06 (kPa/℃) was used for Herat, T is the mean daily air temperature at a height of 2 m (℃), U 2 is the wind speed at a height of 2 m (m/s), d E is the vapor pressure deficit (kPa), es is the saturated air vapor pressure (kPa), andea is the actual air vapor pressure (kPa).

ETc = Kc × ET0 [5]

Where ETc is crop water requirement (mm/day), and Kc is crop coefficient.

ET0nw = 0.408 × ∆ × Rn [6]

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Where ET0nw is simulated case, at which wind velocity is considered zero (mm/day).

ETcnw=Kc × ET0nw [7]

WhereETcnw is crop water required in case in which wind velocity is considered zero (mm/day).

ETCR¿ {ETc−R∧(ETc−R>0)0(ETc−R≤ 0)

[8]

ETcnwR¿ {ETcnw−R∧(ETcnw−R>0)0 (ETcnw−R≤ 0)

[9]

WhereETCR is crop water requirement minus precipitation (mm/day), ETcnwR is crop water requirement at no- wind condition minus precipitation (mm/day) and R is daily precipitation (mm)

RESULTS AND DISCUSSION

1) As mentioned, accessing to the enough and sufficient climatic data is a challenge in Afghanistan due to the lack of enough metrological stations. Therefore, in case of the data collection, there was some problems spatially, the collection of precipitation data for our analysis was challenging. Though, this problem is not essential to ET0. However, details about this problem are shown in (Table 1, and 2).

The collection of sunshine duration data was also challenging. These data was inaccessible because it could not be obtained from the National Climatic Data Center (NCDC). Although it is included in the FAO’s database, a detailed annual analysis is not feasible because only average data is included. However, we could obtain cloud cover measured at Herat Urdokhan research farm.

Table 1. Accessible online database for irrigation planning (2014) [2]

Name FeaturesCROPWAT (FAO)CLIPWAT (FAO)

Date of crops planting, and crop’s Kc.Mean ET0 and that’s component data

NCDC (NOAA) Air temperature, dew point, and wind velocityBasic daily data. The primary data from Figs. 3

Weatherspark.comCloud cover, wind velocity, air temperature, and humidity at the airport. Hourly data may be available. From Figs. 2 and 3.

climatemps.com Average air temperature and precipitation.Monthly average data.

Table 2. Daily missing data of the years

parameterdays/year

2006 2007 2008 2009 2010 2011 2012 2013

Temperature 66 26 14 4 1 0 3 4

Wind speed 66 26 14 4 1 0 3 109

Precipitation 0 0 0 0 360 0 0 360

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2) Based on the experiences of local residence, wind velocity starts since late morning and persist until to the early evening. According to that, the 24-hours interval was divided in two parts named daytime from (10:00 to 22:00) and nighttime from (22:00 to 10:00) with aim to compare the wind intensity in consideration of year 2012 data.

Average wind velocity of daytime and nighttime was calculated separately for both windy and non-windy seasons from 2012. From June to September, this period is locally known as the “120-day winds” in Herat province.

As it is shown in Table 3, in non-windy season, daytime average wind velocity is (2.3 m/s), and the nighttime average is (1.4 m/s). Whereas, in windy season, daytime average wind velocity is (5.4 m/s) in which nighttime average wind velocity is (2.8 m/s), although the length of windy season is shorter than the non- windy season.

Furthermore it is shown in (Fig. 1and 2), the wind velocity is different during the daytime and nighttime entire of the year. In both windy and non-windy seasons, daytime wind velocity is higher than the nighttime, but its rate is two times lower during the nighttime in compare to the daytime, especially in the windy season. In this regards, nighttime irrigation can contribute in terms of water losses reduction.

Table 3 Average wind velocity for both windy season and non-windy season in 2012

Windy Season Non- Windy SeasonTotal Day-time Night-time Day-time Night-time

Average (m/s) 5.4 2.8 2.3 1.4

0

5

10

15

20

Wind velocity at Day-time and Night-time for Non-Windy season

Vel

ocity

(m

/s)

410610

5

10

15

20

Wind Velocity at Day-time and Night-time for Windy Season

Nigt-tim Day-time

Vel

ocity

(m

/s)

8-Sep

Fig. 1. Wind velocity at night-time and daytime Fig.2. Wind velocity at night time and day time separately during the non-Windy season in 2012. separately during the windy-season in 2012.

3) Wind velocity is the most influential factors on ET0. Daily ETrad and ET wind are shown with ET0 in (Fig. 3) that correspond to basic Eq. (1). Furthermore, correlation coefficient (R2) of ETwind is seen large (Fig 4).

1-Jan23

-Jan

14-Feb

7-Mar

29-M

ar

20-A

pr

12-M

ay3-J

un

25-Ju

n17

-Jul8-A

ug

30-A

ug

21-Sep

13-O

ct4-N

ov

26-N

ov

18-D

ec0

5

10

15

20

25ET0 (mm) ETrad ETwind

mm

/day

(g) 2012

ETwindETradET0

0 1 2 3 4 5 6 7 8 90

1

2

3

4

5

6

f(x) = 0.631128520347886 x − 0.4845875201899R² = 0.710838259495221

u2 (m/s)

ET

Win

d (m

m/d

ay)

Fig. 3 ETrad, ETwind, and ET0 in 2012 at Herat, Afghanistan Fig. 4 Pearson correlation between u2 and ETwind

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4) Reducing in wind velocity causes the decreases of ET0. In (Fig. 5), ET0 was shown in both cases; simulated case, in which wind velocity is considered zero (ET0nw), and

the actual case. In compare to the actual case, ET0 is shown lower two times when the wind velocity is close to the zero. Similarly, ETc decreased by reducing wind velocity.

Considering the amount of precipitation, total average amount of crop water requirement ETcR and crop water requirement in no-wind condition (ETcnwR) are shown in (Table 4 and 5) respectively for 8years. In both cases, ETcR

and ETcnwR for each crop are given in millimeter (mm/year). It is seen that, the consumed amount of water by wheats and tomato reduced in simulated no-wind conditions

considerably, (e.g. the required amount of water for tomato reduced almost 4 times in simulated no- wind conditions).

0

5

10

15

20 ET0 ET0nw

(mm

/day

)

ET0nwET0

Fig. 5. A daily simulated ET0nw and ET0 in 2012

Table 4. Total ETcR for three types of wheat and tomato within 8 years in Herat, Afghanistan

crop 2006 2007 2008 2009 2010 2011 2012 2013 Average

(mm/year)Facultative Wheat

989 784 870 633 (651) 684 652 (608)

734

Spring Wheat 368 295 310 60 (187) 178 197 (128)

215

Winter Wheat 538 429 310 200 (376) 304 348 (281)

348

Tomato 1412 1121 1230 1022

(955) 1029 1003 (976)

1093

( ), monthly average metrological data is used instead of daily data due to lack of data.

Table 5 Total ETcnwR for three types of wheat and tomato within 8 years in Herat, Afghanistan

Crops 2006 2007 2008 2009 2010 2011 2012 2013 Average(mm/year)

Facultative Wheat 224 280 187 89 (199) 149 194 (173) 187Spring Wheat 70 91 24 0 (19) 0 27 (0) 13

Winter Wheat 157 168 24 0 (106) 63 105 (61) 83

Tomato 310 368 261 168 (253) 211 261 (252) 260

( ), monthly average metrological data is used instead of daily data due to lack of data.

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5) Wheat form cereal crops and tomato from vegetables are important crops that are produced in large scale in Herat province

Tomato is sensitive in water shortage especially during the flowering stage; the first flowering stage is almost accurse 30 days after planting (C. Brouwer et al., 1989). Tomato is sown in late May that the first flowering stage is match in late July while the evapotranspiration ET0 is larger especially due to higher wind velocity. Similarly, the tomato’s ETcR is also higher in this time. Al already indicated in Table 4, the average amount of ETcR for tomato (average 1093mm/growing season) which is the highest amount in compare of the three types of wheat. However, the growing season of tomato is (145 days) shorter than the growing season of facultative wheat and winter wheat.

As it is shown in Fig. 7 from (A) to (F), tomato’s ETcR the same with facultative wheat is large from early Jun to early July compare to the winter wheat and spring wheat, and the peak ETcR occurred in July which is exceed 10 mm/day for both. This period is coincides with windy season. On the other hand, Kc of both is high at this period Table 6, and furthermore, there is no precipitation from June to October except in same rare cases. Rainfall mostly occurs from October forward until late April sporadically with peak exceeds 8 mm/day.

Winter wheat and spring wheat with 235 and 130 days growing season have the third and the forth rate of ETcR

(average 348 and 215 mm/growing season) respectively Table 3. In Fig. 6 it is seen that, the growing season of both crops coincides with rainfall and on the other hand, there is no strong wind at that period, which means that, the ET0

is low during their growing seasons. The peak ETcR of winter wheat and spring wheat almost 10 mm/day, which occurs when the rain season end.

0

5

10

15

20

25

30 0

2

4

6

8

10

PRCT Facultative wheat Spring Wheat

ET

CR

(mm

/day

)

Prec

ipita

tion(

mm

/day

)

(A) 2006

0

5

10

15

20

25

30 0

2

4

6

8

10

PRCT Facultative wheatE

TC

R(m

m/d

ay)

Prec

ipita

tion(

mm

/day

)

(B) 2007

0

5

10

15

20

25

30 0

2

4

6

8

10


ET

CR

(mm

/day

)

Prec

ipita

tion(

mm

/day

)

(C) 2008

0

5

10

15

20

25

30 0

2

4

6

8

10


ET

CR

(mm

/day

)

Prec

ipita

tion(

mm

/day

)

(D) 2009

0

5

10

15

20

25

30 012345678910


ET

CR

(mm

/day

)

Prec

ipita

tion(

mm

/day

)

(E) 2011

0

5

10

15

20

25

30 0

2

4

6

8

10


ET

CR

(mm

/day

)

Prec

ipita

5ion

(mm

/day

)

(F) 2012

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Fig. 6. from (A) to (F) ETcR of three types of wheat including tomato and precipitation in Herat, Afghanistan

Table 6 crops Kc at different stages

Crops Sowing date

Harvesting date

Initial Crop development Mid-season Late-season

Kc Days Kc Days Kc Days Kc DaysFacultative Wheat 21-Dec 17-Aug 0.7 30 (0.9) 140 1.15 40 0.25 30

Spring Wheat 12-Feb 21-Jun 0.3 30 (0.5) 30 1.15 40 0.3 30

Winter Wheat 22-Oct 13-Jun 0.4 60 (0.5) 75 1.15 75 0.25 25

Tomato 14-Nov 5-Oct 0.6 30 1.15 45 (0.9) 40 0.7 30 ( ) = is expected Kc number.

CONCLUSION

1) There were some problems in data collection, especially sunshine and precipitation data due to the lack of metrological stations in the west part of Afghanistan. Therefore, many different sources are used for data collection purpose. 2) According to the local experiences, the 24-hours interval was divided in two parts named, daytime from (10:00 to 22:00) and nighttime from (22:00 to 10:00). Therefore, average wind velocity of daytime and nighttime was calculated separately for both windy and non-windy seasons from 2012, as the daytime average wind velocity is (2.3 m/s), and the nighttime average is (1.4 m/s). Whereas, in windy season, daytime average wind velocity is (5.4 m/s) in which nighttime average wind velocity is (2.8 m/s), although the length of windy season is shorter than the non- windy season. Hence, nighttime irrigation can contribute in terms of water losses reduction. 3) Wind velocity influenced the ET0, as the daily ETwind is found stranger than the ETrad. Furthermore, correlation coefficient (R2) of u2 with ETwind was found 0.7108.4) ET0 was shown in both cases; simulated case, in which wind velocity is considered zero (ET0nw), and the actual case. Therefore, ET0nw is found smaller two times than the actual case of ET0. Similarly, ETcnw decreased by reducing wind velocity.5) Considering the amount of precipitation, total average amount of crop water requirement ETcR and crop water requirement in no wind condition (ETcnwR) are defined and estimated for 8years. In both cases ETcR and ETcnwR for each crop is given in millimeter (mm/year).

It has been found that, the consumed amount of water by wheats and tomato reduced in simulated no wind conditions considerably, e.g. the required amount of water for tomato reduced almost 4 times. Whereas, the average amount of ETcR for tomato is 1093mm/growing season, which is the highest amount in compare of the three types of wheat. However, the growing season of tomato is (145 days) shorter than the growing season of facultative wheat and winter wheat.

Furthermore, tomato’s ETcR the same with the facultative wheat is large from early Jun to early July compare to the winter wheat and spring wheat, and the peak ETcR occurred in July which is exceed 10 mm/day for both. This period is coincides with windy season. On the other hand, Kc of both is high at this period.

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Winter wheat and spring wheat with 235 and 130 days growing season have the third and the forth rate of ETcR

(average 348 and 215 mm/growing season) respectively. On the other hand, the growing season of both crops coincides with rainfall as there is no strong wind at that period, which means that, the ET0 is low during their growing seasons. The peak ETcR of winter wheat and spring wheat almost 10 mm/day, which occurs when the rain season end.

REFERENCES

Allen, Richard G., et al. 1998. Crop evapotranspiration-Guidelines for computing crop water requirements-FAO

Irrigation and drainage paper 56. FAO, Rome 300.9. D05109.

AB. R. Omid. 2009. Surface Irrigation of Afghanistan. Herat University, faculty of Agriculture. ch. 8.

AFCCC/DOPA Organization. 2001. Full year climatology. Herat, Afghanistan.

C. Brouwer et al. 1986. Irrigation Water Management: Irrigation water needs: Natural Resources Management and

Environment Department-FAO. ch 3.

C. Brouwer et al., 1989. Irrigation Water Management: Irrigation Scheduling-Training manual no. 4: Natural Resources

Management and Environment Department-FAO. ch 2.

Campbell, Gaylon S. 1985. Soil physics with BASIC: transport models for soil-plant systems. Vol. 14. Elsevier.

Doorenbos, J. and A. H. Kassam. 1979. Yield response to water. Irrigation and drainage paper 33: 257.

USAID. 2008. Provincial Agriculture profile. Herat, Afghanistan.

http://afghanag.ucdavis.edu/country-info/Province-agriculture-profiles/reports-usaid-nais/

Ag_brief_2008_Herat_rev1.doc

Ganji H, Rahmany Ab. S, Kajisa T, Kondo M, Hajime N. 2014. Effect of the 120-day winds” on Agriculture and

Environmental Condition in Herat, Afghanistan. Brisbane, Australia. 4th Int. Conf. on International Conference

on Geotechnique, Construction Materials and Environment. pp. 500.

Morison, James IL, et al. 2008. Improving water use in crop production. Philosophical Transactions of the Royal Society

B: Biological Sciences 363.1491: 639-658.

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Oweis, Theib, Heping Zhang, and Mustafa Pala. 2000. Water use efficiency of rainfed and irrigated bread wheat in a

Mediterranean environment." Agronomy Journal 92.2: 231-238.

UNDP. 2008. Provincial profile for Herat province.

http://afghanag.ucdavis.edu/country-info/Province-agriculture-profiles/hirat-herat/Herat.pdf Morison, James

IL, et al. "Improving water use in crop production." Philosophical Transactions of the Royal Society B:

Biological Sciences 363.1491 (2008): 639-658.

Osmanzai, M. 2009. Annual Report. CIMMYT, Afghanistan.

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