Drip irrigation

Drip irrigation
Borisshin · CC BY-SA 4.0 · source
Name	Drip irrigation
Invented	20th century
Inventor	Simcha Blass
Area served	Global
Type	Irrigation method

Drip irrigation is a micro-irrigation technique that delivers water directly to plant root zones through a network of pipes, valves, tubing, and emitters. Developed in the 20th century, it is widely used across diverse climates and crop systems for water-conserving agriculture and horticulture. The method integrates engineering, agronomy, and hydrology to improve crop water productivity and reduce runoff, and it has been adopted in smallholder fields, commercial orchards, and greenhouse operations.

History

Early antecedents of localized water delivery appear in pre-modern waterworks such as the qanat systems of Persia, the water-saving terraces of Inca agriculture, and ancient irrigation methods in Mesopotamia and Ancient Egypt. Modern drip irrigation traces to inventors and entrepreneurs in the 20th century, notably Simcha Blass and companies that commercialized emitters in Israel and later firms in United States, Australia, and Spain. Adoption accelerated with research at institutions like the Food and Agriculture Organization and universities including University of California, Davis and CIMMYT, alongside demonstration projects by agencies such as the World Bank and United Nations Development Programme. Technological diffusion unfolded through collaborations among multinational firms like Netafim, national extension services, and non-governmental organizations such as Heifer International.

Principles and Components

Drip systems rely on hydraulic control, soil-water-plant relations, and emitter hydraulics developed by engineers and agronomists at research centers including Wageningen University, Texas A&M University, and Cranfield University. Core components include pumps and filters manufactured by companies such as Xylem Inc., pressure regulators and valves standard in irrigation catalogs, polyethylene laterals and manifolds produced by polymer firms, and emitters or drippers designed by innovators like Netafim and smaller specialized manufacturers. Sensors and controllers from firms such as John Deere and Schneider Electric integrate evapotranspiration models and data from meteorological services including NOAA for automated scheduling. Soil moisture sensors and tensiometers developed at institutions like CSIRO and INIA inform irrigation decisions for orchards and vineyards studied at research stations like UC Davis Oakville Experimental Station.

Types and Design Variations

Design variations include surface drip, subsurface drip, pressure-compensating emitters, and multi-outlet manifold systems promoted in trials by ICES, FAO demonstration plots, and commercial nurseries affiliated with Royal Horticultural Society research. Subsurface drip systems feature buried laterals used in trials at International Rice Research Institute plots and by growers in the Central Valley (California), while surface drip remains common in greenhouse operations linked to horticultural exhibitions at Chelsea Flower Show. Systems vary with emitter spacing, flow rates, and filtration standards developed in standards bodies like ISO and national regulators such as the Environmental Protection Agency for related water quality considerations.

Installation and Operation

Installation methods are described in manuals produced by extension services at Cornell University, University of Florida, and Ohio State University, and in technical guides from manufacturers such as Netafim and Amiad Filters. Site assessment includes topography analysis akin to studies by USDA NRCS, soil texture classification methods from United States Department of Agriculture, and water quality testing protocols used by municipal systems like Metropolitan Water District of Southern California. Operation employs scheduling frameworks derived from crop coefficients published by FAO papers and evapotranspiration estimates from models developed at Penman and later institutions like CSIRO.

Crop and Water Use Efficiency

Field trials at research centers such as CIMMYT, ICARDA, and university extension plots demonstrate yield responses for crops including grapes studied at University of Adelaide, tomatoes evaluated at Wageningen University, and maize researched at Michigan State University. Drip irrigation enhances water use efficiency metrics promoted by agencies like the United Nations Environment Programme and improves nutrient use efficiency when combined with fertigation protocols developed in industry and tested by laboratories at National University of Colombia and Israeli Volcani Center.

Environmental and Economic Impacts

Environmental assessments by organizations such as the World Resources Institute and economic analyses by institutions like the International Food Policy Research Institute quantify reduced evaporation, lower runoff, and decreased fertilizer leaching compared with flood irrigation in projects executed in regions including California Central Valley, Andalusia, and parts of Sub-Saharan Africa. Economic adoption is influenced by capital costs examined in studies from IFPRI and by subsidy programs run by ministries in countries such as India and Egypt, while private finance from development banks like the Asian Development Bank supports large-scale installations.

Challenges and Maintenance

Operational challenges include emitter clogging documented in tests at Arizona University laboratories, salt accumulation studied by researchers at University of Western Australia, and supply-chain constraints observed in case studies involving firms in East Africa and Latin America. Maintenance protocols recommended by extension services at Oregon State University and equipment manufacturers include filtration, periodic flushing, chemical treatments, and pressure management, with training and capacity-building provided by NGOs such as Practical Action and government programs run by agencies like USAID.

Category:Irrigation