Archived Webinar

Irrigated Agriculture: Introduction to Irrigation Technologies and Applications

Irrigation offers benefits including: yield security during dry seasons and times of drought, economic opportunity by increasing yields, choice of high value market driven crops, multiple cropping seasons annually, out of season production, and protected agriculture. Irrigation is additionally beneficial to nutrient management and can promote food/nutrition security and crop quality. That said, irrigation is not without its disadvantages. Irrigation can confound water scarcity (depletion of water supplies), compete with other water consuming sectors, and raise environmental concerns including pollution, soil salinity and water logging. Irrigation comes only with economic cost, as equipment, labor, maintenance, water, energy all require investment. Irrigation technologies and operation can be separated into gravity fed – surface (flood and furrow) and pressurized (sprinkler and drip) systems. Components of gravity fed systems are: water source and storage, pump (if necessary), and channels or pipes to distribute water to the field. Challenges in surface irrigation include minimizing losses throughout the system and insuring delivery is as uniform as possible. Scheduling of surface irrigation is, at worst, whenever there is water, however much there is, and, at best, based on combined data regarding the soil, crop, and weather. Scheduling for surface irrigation attempts to apply the maximum water per irrigation event and a minimum number of events. Sprinkler irrigation requires water under pressure and delivery to the field via pipes and emitters and can be either stationary or moving. Design of a sprinkler system relies on knowledge regarding pressure-flow relationships in laterals between sprinklers and in the emitters themselves. The basic concept and challenge in sprinkling is to uniformly apply water to a field. Scheduling of sprinkler irrigation is similar to that of flood; return of plant available water in soil each event. Drip irrigation presents a paradigm shift in how we provide water to crops, most importantly due to partial wetting of the soil, providing just plant water needs, enabling very high irrigation frequency and maintenance of relatively high water content in the root zone, and allowing precise nutrient (fertilizer) management together with water management. Drip irrigation systems include: water under pressure, an "irrigation head" with filtration, automation, and fertigation, mains and laterals to deliver to the field and emitters to release water at desired and constant flow rates. Drip systems must be maintained, mostly to prevent clogging. Technology for smallholder drip irrigation will necessarily be site-system-situation specific and will involve appropriate technology and maintenance. Some 65% of water used for agriculture is estimated to not be utilized by plants. Water use efficiency and water saving considerations in irrigated agriculture require proper design and management of water storage and distribution systems to avoid losses and in smart irrigation scheduling. Irrigation technology can be beneficial only in context with the network of institutions, policies and practices that enact it (Venot et al. 2014). Community and institutional organization and support are necessary for its success. Community management includes both aspects of equity and sustainability and is challenged to support development of simple, accessible, affordable but scientific and data-knowledge based methods and systems for irrigation delivery and scheduling. Community/societal contributions and responsibility are important in both the micro and macro scales. At the micro scale this can mean responsibility for water storage and allocation, energy supply, availability of appropriate (location, system, time, crop) technologies, investment, equipment purchase, maintenance, fertilizer purchase, extension – knowledge transfer, and accessibility to markets and marketing. On the macro scale, the community/society must enable investment, maintenance, market driven decision-making and management, and other support including accessibility to knowledge and data. While irrigation and irrigation technologies appear to present opportunity for smallholder agricultural development, economic advancement and poverty alleviation, technology should not and cannot be separated from systems and policies. Appropriate technology for irrigation will always be site and system (crop, economic, social, institutional) specific. Sustainable development of agriculture will be a result of system changes and adjustments. Technology can likely play some role in this. Venot, J-P., et al 2014. Beyond the promises of technology: a review of the discourses and actors who make drip irrigation. Irrig. and Drain. 63: 186–194.

About the Presenters

Alon Ben-Gal

Dr. Ben-Gal is a visiting scientist at the Institute for Water and the Environment and College of Dryland Agriculture at the Mekelle University in Ethiopia. He works as a Senior Research Scientist at the Gilat Research Center in Southern Israel. His professional expertise is on plant response to environmental stress conditions, irrigation of crops, agricultural utilization of saline water and of recycled wastewater, optimization of water under irrigation in arid regions, flow and transport of water and solutes in vadose zone and agricultural systems.

Target Audience

Bank Client countries and Stakeholders in Sub-Saharan Africa

Questions Submitted

DR. YOGENDRA NATH

- Jul 29, 2021
Good.

jose luis

- Jul 13, 2021
que bien

MOHAMMAD

- Jan 20, 2021
Great course! informative and knowledgeable documents.

Nirmal

- Jan 20, 2021
nice course

Joy Mildred Adhiambo

- Dec 13, 2019
Irrigated Agriculture

Anvar

- Oct 16, 2019
Interesting!

Vedat

- Aug 15, 2019
Irrigated Agriculture: Introduction to Irrigation Technologies and Applications

Dr. Illakkuvan

- Jun 7, 2019
Marvelous!

Waqar Aamir

- May 23, 2019
Great

Yusman

- Apr 25, 2019
good job
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