بهبود الگوی خیس‌شدگی خاک در سامانه‌های آبیاری قطره‌ای با تاکید بر مدیریت پالسی

نوع مقاله : مروری

نویسندگان

• ساناز محمدی ¹
• ایمان حاجی راد ²
• عبدالمجید لیاقت ³

¹ گروه مهندسی و مدیریت آب دانشکده کشاورزی دانشگاه تربیت مدرس

² دانشجوی دکتری، گروه مهندسی آبیاری و آبادانی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج، ایران.

³ گروه مهندسی آبیاری و آبادانی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج، ایران

چکیده

کلیدواژه‌ها

• رشد محصول
• توزیع رطوبت
• عملکرد
• گرفتگی قطره‌چکان
• مدیریت آبیاری

موضوعات

• آبیاری و زهکشی

عنوان مقاله [English]

Improving the soil wetting pattern in drip irrigation systems with emphasis on pulsed management

نویسندگان [English]

• sanaz mohammadi ¹
• Iman Hajirad ²
• Abdolmajid Liaghat ³

کلیدواژه‌ها [English]

• Crop Growth
• Dripper Clogging
• Irrigation Management
• Moisture Distribution
• Yield

Improving the soil wetting pattern in drip irrigation systems with emphasis on pulsed management

EXTENDED ABSTRACT

Introduction

Due to the lack of water resources in the world and in Iran, there is a need for effective irrigation techniques in order to contribute to the sustainable development of the agricultural sector with optimal water consumption. In this regard, the use of drip irrigation systems that provide the plant's roots with sufficient water and nutrients at the right time has been widely spread. All irrigation methods, including the drip irrigation systems, can increase water productivity only if they are designed and managed correctly for the specific soil and plant conditions. Therefore, we should look for management techniques that can match the wetting pattern around the irrigation dripper with the root growth pattern in the soil as closely as possible. In this regard, researchers investigated the use of different methods, such as adjusting the depth and intervals of irrigation, utilizing physical, capillary, and hydraulic barriers, as well as pulse management. This knowledge ensures accurate delivery of water and nutrients to the crop root zone, facilitates irrigation planning, and enables matching the soil wetting pattern with the plant root growth pattern.

Materials and Methods

Considering the importance of soil moisture distribution and the effect of improving the dimensions of the soil wetting pattern on crop yield and water productivity in drip irrigation systems, researchers investigated the use of different methods, such as adjusting the depth and intervals of irrigation, utilizing physical, capillary, and hydraulic barriers, as well as pulse management. This knowledge ensures accurate delivery of water and nutrients to the crop root zone, facilitates irrigation planning, and enables matching the soil wetting pattern with the plant root growth pattern. The present study reviewed the experiences of using different management methods to improve the soil wetting pattern and provide experimental equations with an emphasis on pulsed management.

Results and discussion

Pulsed management in drip irrigation systems includes using a series of On and Off cycles. The Off-time cycles in this management allow sufficient opportunity to redistribute moisture in the soil after each irrigation pulse. The results of various researches that have been conducted in the field of using pulsed drip irrigation in the world and Iran show that pulsed management has the possibility of improving the dimensions of soil wetting pattern in the crop root zone. In soils with a light texture, it reduces deep percolation and as a result, reduces the loss of water and nutrients, and in soils with a heavy texture, it causes aeration of the root zone and more appropriate distribution of water and nutrients in the crop root zone, which can lead to improved crop yield. Also, the results of the investigations have shown that the soil wetting pattern around the drippers with high flow rates when using pulse management is similar to the soil wetting pattern produced by the drippers with low flow rates. Due to the fact that in drippers with a low flow rate, the smallness of the dripper opening leads to clogging problems, by using pulse management that allows the use of a dripper with a higher flow rate, the problems related to the clogging of the drippers can be reduced to some extent. In relation to the distribution of salt and nitrate under pulsed drip irrigation system, positive results have also been reported by researchers, but due to the importance of the issue, more extensive research is needed in this field.

Conclusion

In recent years, pulsed drip irrigation has replaced the usual (continuous) irrigation method due to its efficiency and saving in water consumption, the ability to precisely adjust the amount of water required by plants and reduce irrigation costs. Also, this irrigation method plays an important role in reducing soil and water pollution. The purpose of this study is to investigate the results of pulsed drip irrigation systems in Iran and the world. The studies show that pulsed drip irrigation can have a positive effect on the plant growth and yield. This type of irrigation increases the absorption of water and nutrients by plants and also increases root activity and the development of the root system of plants. In addition, pulse irrigation can improve the distribution of moisture in the soil and prevent the accumulation of water in a certain point. This causes the evaporation of water from the soil and the evaporation of transpiration of plants to happen in a more uniform way and leads to the improvement of irrigation efficiency. Also, pulse irrigation can have a positive effect on the clogging of irrigation drippers.