IMPROVING SOIL AND NUTRIENT MANAGEMENT SYSTEMS FOR SUSTAINED PRODUCTIVITY AND ENVIRONMENTAL QUALITY
Location: Soil Plant Nutrient Research (SPNR)
Title: Management of Dryland Saline Seeps
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: December 20, 2007
Publication Date: January 6, 2012
Citation: Halvorson, A.D., Richardson, J. 2012. Management of Dryland Saline Seeps. Chapter 18. p. 561-589. In Agricultural Salinity Assessment and Management, Second Edition. (W.W. Wallender and K.K. Tanji, eds) ASCE Manuals and Reports on Engineering Practice No. 71, 2nd edition. Reston, VA.
Interpretive Summary: This paper discusses the identification, diagnosis, control, and reclamation of dryland saline seeps in the North American Great Plains. Saline seep describes a salinization process accelerated by dryland farming practices which allow water to move through salt laden substrata below the root zone. Water moving past the root zone accumulates above a nearly impermeable geologic stratum forming a perched water table which eventually surfaces at a down slope position to form a saline seep. Subsurface drains are effective for obtaining hydraulic control of a seep, but disposal of the salty water is a problem and not cost effective for dryland crops. Many saline seeps can be controlled by establishing perennial deep-rooted crops in the recharge area. Farmers can also use intensive, flexible cropping systems to improve crop water-use efficiency for saline seep control in combination with soil, water, and crop management practices to reduce the need for summer fallow. Once hydraulic control is achieved in the seepage area, reclamation procedures to leach the salt from the soil profile can proceed. With proper management and time, crop production can be restored to near normal yield levels in the former saline seep area.
Discussed is the identification, diagnosis, control, and reclamation of dryland saline seep problems as found in the North American Great Plains. Saline seeps develop because of geologic stratifications within the soil profile and insufficient use of precipitation by crops used in dryland farming systems. The process of saline seep development results in salinization of productive dryland soils and shallow groundwaters in localized areas. Establishing perennial deep-rooted crops in recharge areas is effective in controlling saline seeps. Establishing intensive, flexible cropping systems to improve crop water-use efficiency in combination with soil, water, and crop management practices to reduce the need for summer fallow is also effective for saline seep control. Once the saline seep area has been hydraulically controlled, reclamation procedures can be implemented. Productivity of the former seepage area can be restored to near normal yield levels with time.