ARS | Publication request: Impact of Sustained Deficit Irrigation on Spearmint as a Water-Saving Technique

Submitted to: International Soil and Water Conservation Conference
Publication Type: Proceedings
Publication Acceptance Date: July 1, 2009
Publication Date: January 15, 2010
Citation: Okwany, R., Peters, T.R., Ringer, K.L., Walsh, D., Boydston, R.A. 2010. Impact of Sustained Deficit Irrigation on Spearmint as a Water-Saving Technique. International Soil and Water Conservation Conference.

Technical Abstract: An experiment is being conducted to quantify the local response to different levels of water deficit on yield and crop water requirement of spearmint in the Pacific Northwest arid environment. A line source sprinkler system is used to apply varied water deficit amounts based on spatial location from the center of the irrigation line from full irrigation to 100% water deficit. All deficit irrigated treatments show significant reduction in gross biomass yield. The provisional results indicate that higher deficits resulted in reduced biomass yield whereas the irrigation water use efficiency and dry to wet biomass ratio was significantly increased while the total oil yield of the spearmint increased. Mint oil yield shows an exponential increase with irrigation deficit. This study indicates that spearmint is a suitable crop for sustained deficit irrigation management strategy to reduce farm operation technicalities of regulated deficit irrigation while considerably conserving water for irrigation. Deficit irrigation of mint is thus shown to contribute to yield quantity and quality sustainability under reduced water availability but an economical farm operation requires site-specific recommendations since crop-marketable quantity and quality parameters for each site may be different.