Click on “Download PDF” for the PDF version or on the title for the HTML version.
If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.
Enhancing Subsurface Drainage to Control Salinity in Dryland Agriculture
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org
Citation: Applied Engineering in Agriculture. 33(6): 819-824. (doi: 10.13031/aea.12252) @2017
Authors: Harold Steppuhn, L. J. Bruce McArthur
Keywords: Agricultural drainage, Plant emergence, Pre-seeding irrigation, Solar-powered pumping, Soil reclamation, Soil salinity, Windbreaks.
Abstract. Controlling the physical processes of soil salinization involves lowering ground water levels, draining the vadose zones, and leaching excess salts from root zones. Plastic drain tubing strategically placed 1.5 to 1.8 m below the surface in semiarid lands can lower water tables and drain phreatic water, but irrigation is usually required to satisfactorily leach the offending salts. In non-irrigated drylands, the leaching process depends on natural precipitation, but the drier the climate, the greater the need for more leaching water. Possible practices which tap complementary water in conjunction with subsurface drainage include: (1) establishment of roughness barriers to trap wind-borne snow, and (2) pumping water from near-surface, ground water mounds. The mean electrical conductivity of saturated soil paste extracts sampled yearly from a semiarid site in Saskatchewan averaged 14.1 dS m-1 during the six years before the drainage was installed, 13.0 dS m-1 for two years just after drainage but before capturing blowing snow, and 9.6 dS m-1 for the six years following. The average barley grain harvested during the six years prior to drainage yielded 330 kg ha-1 and 2414 kg ha-1 after installation of the enhanced drainage system. In a follow-up sub-study, fall applications of 4.6 dS m-1 mounded ground water from a shallow well fitted with a solar-powered pump within a drainage system preceded spring seeding of alfalfa. Enhanced drainage improved mean seedling emergence from 20% to 79%. Every 28 mm of ground water applied, up to 2273 mm, increased alfalfa emergence by 1%.
(Download PDF) (Export to EndNotes)