Management practices to save irrigation water by reducing evaporation in semi-arid region

العناوين الأخرى

ممارسات إدارية لتوفير مياه الري من خلال تقليل مياه التبخر في المنطقة الشبه جافة

مقدم أطروحة جامعية

Haydar, Abd al-Rahman Perdawood

مشرف أطروحة جامعية

Karim, Tariq Hama

الجامعة

جامعة صلاح الدين

الكلية

كلية الزراعة

دولة الجامعة

العراق

الدرجة العلمية

دكتوراه

تاريخ الدرجة العلمية

2012

الملخص الإنجليزي

All praise and thanks are due to my Lord Allah for giving me the inspiration, patience, time, strength and knowledge to complete this work.

I am deeply indebted to my supervisor, Professor Dr.

Tariq Hama Karim for his advice, supervision, encouragement and valuable suggestions throughout this work.

This work would not have been possible without the guidance and the help of several individuals in one way or another contributed and extended their valuable assistance in the preparation and completion of this stud I would gratefully acknowledge the support and sincerity of the President of th University Salahaddin, Dr.Ahmed Dizayee and the deanery of the college of Agriculture, especially Dr.

Sherzad Aumer and Dr.

Sardar Y.

Sardary for providing facilities and their continuous support and encouragement.

My heartfelt thanks and best gratitude are also extended to the member of the examination committee for evaluating the content of the thesis and offering their valuable criticisms.

Thanks are also due to Dr.

Raed, the Previous Dean Assistant for scientific affairs, and Mr.

Soran Zanoon, the Dean Assistant for administrative affairs for their advices and assistance.

My gratitude and appreciation are also dedicated to Dr.

Alwand Dizayee, Head of Soil and Water Science Department, and the Department Coordinator Mrs Saywan Karkuky for their guidance and continuous encouragement during the entire period of the study.

I also appreciate the assistance of Mr.

Ali Husain, for his help in data analysis.

I offer deep thanks to the officials of the agro meteorological center/ General Directorate of Agriculture and those of the Erbil agro meteorological station, especially Mr.

Hogir H.

Homer and Mis Nishtiman for providing me with most of collected meteorological data.

Also I would like to thank my friends (Dr.Zahir Amin, Dr.Akram A.Khalaf, Mr.Fuad M.Ahmed, Mr.Ismial T.Muhammad, Mr.Darsim B.Ismial, Mr.

Azad S.

Ahmed, Mr Kamyar, and Mr.

Xazi Karkuky) for their helps encouragements during this study.

Much more thanks to all those who have helped me and have not been named.

Abd-El Rahman The success of revegetation projects usually requires an appropriate plan.

Establishing plants in semi-arid climate can be challenging even with supplemental irrigation.

In this zone, soil evaporation constitutes a significant fraction of the total evapotranspiration during the summer season.

Better understanding the effect of mulching, shading and other practices help determine management strategies to conserve water to irrigate as well as dryland crop production.

The reservationists must use the most appropriate and cost effect means to deliver water to the root zone of newly planted plants in order to maximize survival and growth.

Consequently, this investigation was undertaken with the object of increasing water availability through evaporation reduction by applying an array of techniques, which encompassed mulching, shading, sheltering and introducing alternative irrigation systems.

To target the above objectives, sequential field experiments were conducted at two sites within Erbil Governorates during the summer seasons of 2009 and 2010 The outlines of these experiments can be summarized as follows A.

Effect of mulching and shading treatments on soil evaporation from minilysimeters.

This experiment was performed to test the performance of some selecte mulching and shading treatments on reducing soil water loss evaporation suppression from a loamy soil obtained from Girda Rasha site and packed in minilysimeters.

The minilysimeters were irrigated and exposed to the environment during the period from Jun 16th to July 10th 2009.

The same experiment was carried out for the second run under a higher external evaporativity.

B.

The impact of some selected treatments on evaporation suppression and growth of olive To extrapolate the results of Experiment A1 and A2, the treatments which offered the high performance during these experiments were selected and applied in presence of olive (Olea europaea) seedlings grown in the loamy soil at the Gridarasha site.

Olive growth and survival besides soil temperature at a depth of 5cm were monitored C.

Survivorship and growth of casuarinas seedlings under different alternative irrigation systems.

This trial was carried out to compare the effectiveness of seven selected irrigation methods on growth, and survival of casuarinas seedlings (Casuarina equisetifolia) grown in the loamy soil at Girdarasha site during diameter was allocated for each the period from 6th July to October 18 th 2010.A circular plot 40 cm in plant D.

Lithic mulching.

This experiment was performed to study the effect of mixing different rates of lithic materials with the top 9-cm of the loamy soil packed in minlysemeters on soil evaporation.

The soil rock fragment content (SRFC) ranged from 0 to 100 %.

The columns were exposed to two different environmental conditions at Girdarash site during the summer season of 2010.

E.

Impact of windbreak on evaporation suppression from different textured soils.

The specific objective of conducting this experiment was to determine the extent to which the existing windbreaks at Kasnazan site could mitigate evaporation rate from three different textured soils packed in minlysemeters.

The soil columns were laid down at different leeward distances ranged from 0 to 50 m and exposed to different evaporation demands during the growing seasons of 2009 and 2010.

The main results of the above experiments can be summarized as follows : A.

Effect of mulching and shading treatments on soil evaporation from minilysimeters.

1.

The first stage evaporation was distinguished under a few treatments during the first run (medium evaporation demand), but it was distinguished under the majority of the treatments during the second run (higher evaporation demand).

This stage was very short did not exceed three days.

2.

Periodic measurement of evaporation rates indicated that the some treatments like reed cage, rubber and wood box exhibited high evaporation rates in the early stage of the experiments and were close to those occurred under the control treatment.

3.

The soil mulching treatments appeared to reduce the evaporation rate much more than shading treatments.

Among the mulching treatments, coarse chalk and white cork offered the best performance.

4.

In an examined period 10 days the effect of coarse chalk and white cork mulches as water saving can be quantified in term of 29 and 22 mm water during the first run and 28 and 25 mm water during the second run B.

The impact of some selected treatments on evaporation suppression and growth of olive.

1.

The control treatment utilized the highest depth of available water, but the majority of depletion was due to evaporation from the soil surface.

2.

On the average the white cork treatment saved the highest amount of available water between two successive irrigations and the white polyethylene the next highest followed by wood fiber, coarse chalk, wood box and control 3.

When both seedling height and stem diameter were considered collectively, the treatments were effective in enhancing olive growth in the order : Coarse chalk > Wood box > White cork>Wood fiber> White polyethylene> Control 4.

The soil temperature at a 5–cm depth under coarse chalk or white cork was lower by as much as 7 o C compared with the check treatment.

5.

No mortality occurred under the treatments even under the control treatment during dry growing seasons of 2009 and 2010.

C.

Survivorship and growth of casuarinas seedlings under different alternative irrigation systems 1.

The cumulative survival under the control and surface watering treatments dropped to zero after 14 and 38 days from planting respectively.

In contrast to these treatments, no mortality occurred during the study period under the remaining treatments.

2.

It can be elucidated from the results that the vertical tube coupled with straw mulching produced the highest plant height and drip emitter fitted to a vertical tube the next highest.

3.

The percentage of reduction in plant height under limited irrigation of 50 % was about 22 % compared to that under full irrigation.

4.

Overall different alternative irrigation systems gave rise to increased growth in stem diameter of casuarinas seedlings.

5.

It was also observed that the buried clay pot irrigation and the control treatments offered the highest and lowest volume growth respectively.

6.

It was discerned that there was a gradual increase in volume growth with decrease in deficit water application.

Furthermore, via using drip emitter fitted to a vertical tube, saving of 30 % irrigation water could be easily achieved without significant reduction in casuarinas seedling growth parameters.

7.

It was observed that the seedlings which received 0.5 times the soil water depletion, offered significant reduction in growth volume and root length.

D.

Lithic mulching 1.

The first stage (the atmosphere or energy limited stage), where water flow is dominated by liquid water flow, was absent.

2.

The results also indicated that there was a slight increase in d0.5 over the range of soil rock fragment content (SRFC) from 0 to 30 %, beyond which the value of the parameters went up to 10.72 and 9.28 days under high and low external evaporativity conditions respectively 3.

The cumulative evaporation at the date of termination of the experiment (1 st run)-High evaporation demand- ranged from as low as 40.14 mm under a SRFC of 100 % to as high as 60.95 mm under the control treatment.

On the other hand, it ranged from a minimum of 35.61 mm under a SRFC of 100 % to a maximum of 52.01 mm under the control at the date of termination of the experiment (2nd run)-low evaporation demand.

4.

The relationship between the cumulative evaporation after any elapsed time and SRFC was described by a linear model.

The coefficient of determination (R2) of the best fit line was ± 0.93 in most cases.

5.

amongst the models which offered the highest accuracy of prediction of cumulative evaporation under the control and under a SRFC of 100% was the modified form of the Black model.

The relative error was below 20 % in most cases.

Apart from this, the power function gave the highest accuracy of evaporation rate prediction, which indicated by a root mean square error RMSE of less than 1 mm d-1 in most cases.

E.

Impact of windbreak on evaporation suppression from different textured soils.

1.

The results illustrated that the cumulative evaporation at a specified day tended to increase with an increase in distance leeward of the windbreak.

The results also revealed that there was a very slight change in cumulative evaporation as the distance increased from 35 to 50 m in most cases.

2.

Nearly, all the investigated soils exhibited similar trends.

The loamy soil offered a higher cumulative evaporation at the end of the dry cycle compared with that from the silty clay soils.

3.

The relation between the cumulative evaporation at a specified day and the distance leeward of the windbreak was slightly affected by evaporation demand 4.

The results also indicated that relative evaporation Kr was below 1.0 in most cases suggesting that the sheltered area extended beyond 50 m.

There appeared numerous cases where the relative evaporation at distances of 35 and 50 m exceeded 1.0 (equivalent to 6.8 H to 8.3 H), reflecting that these points were within the wake zone.

5.

Comparison of Kr and relative wind speed Ur during a given time, revealed that the curve of variation of wind speed Ur over distance is not parallel to the curve of Kr.

التخصصات الرئيسية

العلوم الزراعية

الموضوعات

• الإدارة
• الموارد المائية
• مياه الري

عدد الصفحات

137

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-314554