نوع مقاله : مقاله پژوهشی
نویسندگان
1 محقق آبیاری و زهکشی، گروه تحقیقات آبیاری و زهکشی، موسسه تحقیقات و آموزش نیشکر خوزستان، اهواز، ایران
2 محقق گروه تحقیقات به‌زراعی، مؤسسه تحقیقات و آموزش نیشکر خوزستان، اهواز، ایران
3 گروه تحقیقات آبیاری و زهکشی مؤسسه تحقیقات و آموزش نیشکر خوزستان، اهواز، ایران
4 استاد گروه آبیاری و زهکشی، دانشکده مهندسی آب و محیط زیست، دانشگاه شهید چمران اهواز، اهواز، ایران
5 مؤسسه تحقیقات و آموزش نیشکر خوزستان، اهواز، ایران
چکیده
یکی از چالش‌های آبیاری قطره‌ای زیرسطحی در مناطق خشک و نیمه خشک، تجمع املاح در لایه سطحی خاک است. این پژوهش به‌منظور بررسی تغییرات شوری و سدیمی-شدن خاک در دو مزرعه آزمایشی آبیاری قطره‌ای زیرسطحی و آبیاری جویچه‌ای واقع در کشت و صنعت حکیم‌فارابی خوزستان انجام شد. در این تحقیق تغییرات شوری خاک در عمق‌های 30-0، 60-30 و 90-60 سانتی‌متری و تغییرات نسبت جذب سدیم (SAR) در لایه سطحی (30-0 سانتی‌متری) خاک، در طول دوره رشد نیشکر (دو (T1)، چهار (T2)، شش (T3)، هشت (T4)، ده (T5) و دوازده (T6) ماه پس از شروع آبیاری) بررسی شد. نتایج نشان داد هدایت الکتریکی (EC) خاک در عمق‌های 30-0 و 60-30 سانتی-متری، در همه زمان‌های مورد بررسی بجز T1 و T5 (انجام آبیاری سطحی در مزرعه قطره‌ای زیرسطحی)، به‌طور معنی‌داری تحت تأثیر روش آبیاری قرارگرفت. بیش‌ترین اختلاف بین مقدار EC خاک در مزرعه آبیاری قطره‌ای زیرسطحی با مزرعه آبیاری جویچه‌ای، مربوط به زمان‌های نمونه‌برداری T3 و T4 بود.غلظت سدیم محلول و مقدار SAR خاک در عمق 30-0 سانتی‌متری خاک، در همه زمان‌ها به‌جز T5، در مزرعه آبیاری قطره‌ای زیرسطحی، به‌طور معنی‌داری بیش‌تر از مزرعه آبیاری جویچه‌ای و در زمان T5، به‌طور معنی‌داری کم‌تر از آبیاری جویچه‌ای بود. در زمان نمونه‌برداری T5، انجام آبیاری سطحی در مزرعه آبیاری قطره‌ای زیر سطحی، سبب آبشویی املاح لایه سطحی خاک و کاهش SAR خاک شد. بنابراین در کنار استفاده از سیستم آبیاری قطره‌ای زیرسطحی در شرایط مناطق خشک و نیمه خشک خوزستان، نیاز است که امکان آبیاری به‌روش سطحی نیز به‌منظور مدیریت شوری خاک فراهم گردد.
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
Changes in soil salinity and sodicity under subsurface drip irrigation and furrow irrigation of sugarcane
نویسندگان [English]
- Elham Zanganeh-Yusefabadi 1
- Akbar Karimi 2
- Ali Sheini-Dashtegol 3
- Abedali Naseri 4
- Shaban Zarei 5
1 Researcher of Irrigation and Drainage, Department of Irrigation and Drainage, Khuzestan Sugarcane Research and Training Institute, Ahvaz, Iran
2 Researcher, Department of Agronomy, Khuzestan sugarcane research and training institute, Ahvaz, Iran
3 Department of Irrigation and Drainage, Khuzestan sugarcane research and training institute, Ahvaz, Iran
4 Professor. Department of Irrigation and Drainage, Faculty of Water and Environment Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran
5 Khuzestan sugarcane research and training institute, Ahvaz, Iran
چکیده [English]
Introduction
In arid and semi-arid regions, optimal use of water resources and management of soil resources is necessary to achieve sustainable agriculture. Accumulation of solutes in the surface layer of the soil is one of the challenges of subsurface drip irrigation, especially in arid and semi-arid regions. In the drip irrigation system, the distribution and accumulation of soluble soil salts in the surface layer of the soil is more than the deeper layers and it increases with increasing distance from the drippers. Soil salinity in the subsurface drip irrigation method should not be ignored, because in this irrigation method, even in good water quality conditions, some amount of water is transferred to the soil and the salt concentration on the soil surface gradually increases. Therefore, it is necessary to monitor and control the soil salinity in subsurface drip irrigation conditions. This study was carried out in order to investigate the soil salinity and sodicity status under subsurface drip irrigation and furrow irrigation during sugarcane growth period.
Methodology
This study was carried out in two experimental fields of subsurface drip irrigation (with a drip irrigation depth of 20 cm) and furrow irrigation located in the Khuzestan Hakim-Farabi Agro-Industry. In this study, the changes in soil salinity at the depths of 0-30, 30-60, and 60-90 cm and sodium absorption ratio (SAR) in the surface layer (0-30 cm) were investigated during the growth period of sugarcane (2 (T1), 4 (T2), 6 (T3), 8 (T4), 10 (T5) and 12 (T6) months after the start of irrigation). The average data were compared using the t-test at the 5% probability level.
Results and Discussion
The results showed that at all sampling times, electrical conductivity (EC), concentration of soluble cations (Na, Ca and Mg) and SAR of the soil in the subsurface drip irrigation field were more than the furrow irrigation field. The results indicated that the soil electrical conductivity (EC) at both the depths of 0-30 and 30-60 cm, in all investigated times except 2 and 10 months after the start of irrigation (surface irrigation in subsurface drip field), was significantly affected by the irrigation method. The results of this research showed that in all sampling times of salinity, the concentration of soluble cations (Na, Ca and Mg) and SAR of the soil in the subsurface drip irrigation field was higher than that in the furrow irrigation field. The greatest difference in the soluble concentration of Na, Ca and Mg in the soil in the two studied fields was related to the T4 (8 months after cultivation). At this sampling time, the average soil soluble concentration of Na, Ca and Mg in the subsurface drip irrigation field was 2.1, 1.95 and 1.93 times their values in the furrow irrigation field, respectively. In all sampling times except T5, the soil SAR at the 0-30 cm depth, in the subsurface drip irrigation field, was significantly higher than in the furrow irrigation field, and in T5 sampling time, it was significantly lower than farrow irrigation. At the T5 sampling time, surface irrigation in the sub-surface drip irrigation field led to leaching of accumulated salts especially Na in the surface layer of the soil and reduced the soil SAR.
Conclusions
According to the results of this study, it seems that besides using a subsurface drip irrigation systems in arid and semi-arid regions (like Khuzestan Province), it is necessary to provide the possibility of surface irrigation in order to manage soil salinity and sodicity. Moreover, considering that sugarcane is a perennial plant, it is necessary to pay attention to soil solute leaching in order to control salinity in the management of sugarcane fields.
کلیدواژه‌ها [English]
- Irrigation system
- Soil soluble cations
- Sodium absorption ratio (SAR)
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