English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Understanding water and nutrient movement in arid climate-regulated deficit, drip-irrigated vineyards is imperative for understanding grape vine canopy management. However, little research has been conducted in these environments to aid in the understanding of where the vine accesses nutrients and/or soil water and how that translates into soil and/or plant tissue sampling approaches. We used bromide (Br) as a tracer to study nitrate movement in soils as well as into grape leaves in two ‘Merlot’ vineyards in central Washington State. Bromide movement closely followed water movement. Although Br was detectable in grape petioles, it was not detectable in leaf blades, likely as a result of a dilution factor related to the amount of tissue. Relationships between soil Br and soil moisture as well as petiole and soil Br concentrations suggests that soil sampling for nitrate should be taken from a diagonal position between the vine and the emitter, between 20 and 60 cm from the drip line. This is consistent with the recommendation for soil moisture sampling in a published companion study. Water movement in regulated deficit irrigated wine grape vineyards in the inland Pacific Northwest has been shown to be restricted to a fairly small zone and often soil moisture status is very low (Davenport et al., 2008). Because plant nutrient availability and, in the case of NO3-N, movement are closely related to soil moisture distribution, the results of soil moisture studies suggest that mobile anionic plant nutrient distribution may be found in specific zones in the soil. Bromide is routinely used as a tracer for mobile anionic plant nutrient movement (e.g., nitrate, chloride) in the soil (Fisher and Healy, 2008; Green et al., 2005; Izadi et al., 1993; Logsdon, 2007; Schuh et al., 1997; Seo et al., 2005) as well as in studies looking for offtarget movement affecting groundwater in delicate ecosystems (Elc xi and Molz, 2009; Woodward et al., 2009). In addition, it has successfully been used as a tracer of nitrogen (N) movement in both soils and plants (McLeod et al., 1998; Patra and Rego, 1995). Although most of the work using Br as a tracer in agricultural systems has focused on annual crops such as corn, wheat, potato, and cotton (Izadi et al., 1993; Kessavalou et al., 1996; Ottman and Pope, 2000; Silvertooth et al., 1992), work in the perennial forage crops (Blumenthal et al., 1999; Magarian et al., 1998; Schnabel et al., 1995) and in the citrus trees (Harrison et al., 1999) have shown Br to be a valid tracer of movement in many soil and plant systems. Magarian et al. (1998) used a combination of N-labeled ammonium nitrate and Br as KBr to trace N movement in alfalfa. They found that NO3 and Br uptake was consistent across numerous alfalfa germplasms, suggesting that Br is a cost-effective alternative to N-labeled compounds to trace N use in plants. Bromide has also been successfully demonstrated to be a useful tracer in studies of spatial and temporal distribution of nutrients in soils (Kohne and Gerke, 2005). Kessavalou et al. (1996) used Br and N in a corn field to trace NO3-N leaching to groundwater and found that Br and the N followed similar patterns in non-irrigated cropping systems. Schuh et al. (1997) found similar results with Br and nonlabeled NO3-N. Soil sampling for nutrients, and N in particular, is challenging in perennial cropping systems. Recent research has shown very low soil moisture levels in deficit drip-irrigated wine grape vineyards in the inland Pacific Northwest with significant variation within the season (Davenport et al., 2008). This suggests that, rather than random soil sample collection, there may be a specific location in the soil in relation to vine and drip emitter location to best reflect vine root nitrate extraction. We used Br as a tracer for nitrate movement in regulated deficit drip-irrigated vineyards in the inland Pacific Northwest. Our hypothesis was that Br movement would closely follow water distribution patterns in drip-irrigated vineyards (Davenport et al., 2008). Our objective was to develop an understanding of the distribution of Br as a surrogate for NO3-N and other mobile anions within the wetted root zone. Based on this understanding, we strove to determine the most representative location for soil sample collection for assessing the availability of mobile anionic nutrients when dripapplied in regulated deficit-irrigated vineyards. Materials and Methods The sites for this research were two dripirrigated winegrape (Vitis vinifera L.) vineyards near Prosser, WA (between lat. 46 15’ and 46 18’ and long. 119 32’ and 119 48’). Both were planted with own-rooted ‘Merlot’ and managed from inception using regulated deficit drip irrigation (Evans, 1993, Evans et al., 1993). Vines were spaced with 1.83 m between plants and 3.05 m between rows. In each vineyard, individual drip emitters within a 15to 20-cm distance from a vine trunk were identified. As per Rolston et al. (1991), each emitter was considered fixed in space for the duration of the single season of sampling. A half radial pattern was marked around each emitter spanning 60 cm both left and right of the emitter in the row and to a distance of 60 cm into the interrow (Fig. 1). Row orientation in both vineyards was north–south. All emitters were rated at 2 L h. Additional information on year of planting, soil series, texture, annual irrigation applications, and precipitation during the time of this study is available in Davenport et al. (2008). Six replicates (emitters within 15 to 20 cm from vine trunk) were treated in one row in each vineyard with a minimum of three vines between sample vines. The Br application was made just before veraison (670 degreedays, base 10 C; Keller et al., 2004) to be consistent with standard N application timing for winegrape vineyards in this growing area (R. Smithyman, personal communication). Midway through the 670 degree-day irrigation event, 200 mL of a KBr solution (225 mg L) was applied by placing the solution in a small cup with a hole, sized to drip at the same rate as the emitter, hung directly under the emitter (Waters et al., 2005) and left on for the duration of the irrigation event. Soil Received for publication 18 Oct. 2010. Accepted for publication 16 Nov. 2010. This research was funded by grants from the Northwest Center for Small Fruit Research with supplemental funding from the Washington State University Agriculture Research Center. We thank those diligent diggers, Jaimi Marden, Tyler Phillips, Kelsey Myers, and Joanna Pierce, and Drs Troy Peters and Bill Pan for their review comments. Professor, Soil Scientist, Emeritus Extension Soil Scientist, and Agric. Res. Tech. II. Scientist. To whom reprint requests should be addressed; e-mail jdavenp@wsu.edu. HORTSCIENCE VOL. 46(2) FEBRUARY 2011 291 | SOIL MANAGEMENT, FERTILIZATION, AND IRRIGATION

Spatial and Temporal Distribution of Bromide as a Nitrate Tracer in Deficit, Drip-irrigated Wine Grape Vineyards