Grape production in the low rainfall environment of the inland Northwest requires the use of irrigation. A recent survey indicated that in Washington State, over 61% of grape acreage apply this water through drip irrigation and over 75% of this involves a type of deficit irrigation water management (M. Olmstead, personal communication).
Water distribution under drip emitters varies both spatially and temporally (Rolston et al., 1991). Stevens and Douglas (1994) found that grape root distribution (measured as root length) under drip irrigation was concentrated within the vine row, whereas under microjet sprinkler irrigation, roots were dispersed out between the rows, both patterns reflecting the wetted area. Both young and established grapes have been shown to have the highest periods of moisture demand in a double sigmoidal curve that parallels berry development (Klein, 1983; Stevens and Harvey, 1996). Furthermore, soil moisture depletion under drip irrigation has been demonstrated to a depth of 120 cm (Stevens and Harvey, 1996). These patterns of root distribution and soil moisture depletion have implications for vineyard management. Placement of soil moisture-monitoring devices (e.g., neutron probe access tubes, tensiometers) as well as soil sampling for testing vineyard soil chemistry status (Rolston et al., 1991) are affected by these relationships. The objective of this experiment was to develop an understanding of soil moisture distribution patterns in regulated deficit, drip-irrigated vineyards in the low rainfall area of the inland Northwest. We hypothesized that current in-row soil moisture monitoring does not best align with soil moisture distribution patterns in deficit-irrigated vineyards and, thus, a moisture zone for monitoring could be identified.
KellerM.MillsL.J.WampleR.L.SpaydS.E.2004Crop load management in Concord grapes using different pruning techniquesAmer. J. Enol. Vit.553550
ReichardtK.Araújo SilvaJ.C.BassoiL.H.TimmL.C.OliveiraJ.C.M.BacchiO.O.S.PilottoJ.E.2001Soil spatial variability and the estimation of the irrigation water depthSci. Agr.58549553
RolstonD.E.BiggarJ.W.NighingaleH.I.1991Temporal persistence of spatial soil-water patterns under trickle irrigationIrr. Sci.12181186
StevensR.M.DouglasT.1994Distribution of grapevine roots and salt under drip and full-ground cover microjet irrigation systemsIrr. Sci.15147152