Using EM and VERIS technology to assess land suitability for orchard and vineyard development

Abstract

Orchard and vineyard producers conduct preplant site evaluations to help prevent planting permanent tree and vine crops on lands where the crop will not perform to its highest potential or attain its full life expectancy. Physical soil characteristics within specific soil profiles and spatially throughout an orchard influence decisions on land preparation, irrigation system selection, horticultural choices, and nutrient management. Producers depend on soil surveys to help them understand the soil characteristics of the land and may be interested in technology that provides additional information. Electromagnetic induction (EM38) and four-probe soil resistance sensors (VERIS) are being used in combination with global positioning systems to map spatial variability of soils using apparent soil electrical conductivity (ECa). The hypothesis evaluated in this study is whether rapid, in situ, and relatively low-cost methods of measuring ECa (EM38 and VERIS) can effectively identify and map physical soil variability in non-saline soils. The supposition is that in non-saline soils, ECa levels will relate well to soil texture and water-holding capacity and can be used to map physical soil variability. In turn, the information can be used to guide decisions on preplant tillage, irrigation system design, water and nutritional management, and other horticultural considerations. Two sites in the Sacramento Valley were mapped each with EM38 and VERIS methods. Site-specific management zones were identified by each provider on ECa maps for each site, and then soil samples were collected by University of California researchers to verify these zones. Results showed that on non-saline soils, ECa measured with both EM38 and VERIS correlate with physical soil properties such as gravel, sand, silt, and clay content but the relationship between conductivity and these physical soil properties varied from moderately strong to weak. The strength of the correlation may be affected by several factors including how dominant soil texture is on conductivity relative to other soil properties and on methods of equipment operation, data analysis and interpretation. Overall, the commercial providers of ECa surveys in this study delivered reasonable levels of accuracy that were consistent with results reported in previous studies. At one site, an ECa map developed with VERIS provided more detail on physical soil variability to supplement published soil surveys and aided in the planning and development of a walnut orchard. At a second site, almond yield appeared to correlate well with distinctly different soil zones identified with EM38 mapping.

Identifying irrigation zones across a 7.5-ha ‘Pinot noir’ vineyard based on the variability of vine water status and multispectral images

“…The EC e content here was related to the soil and not to water which was of a good quality according to the standards defined by Ayers and Wescot (1985) (data not shown). Some studies have explored soil EC e as an indicator of soil texture for mapping vineyard spatial variability based on soil texture (Corwin and Lesch 2005;Fulton et al 2010). However, in our study, EC e was significantly related only to silt content.…”

“…In fact, a significant relationship was found between soil depth and W L and between soil depth and yield in 2006 and 2007. Soil EC e can be influenced by both static and changing factors including water quality, soil texture, mineralogy, soil water content, bulk density and temperature (Friedman 2005;Fulton et al 2010;Johnson et al 2003). The EC e content here was related to the soil and not to water which was of a good quality according to the standards defined by Ayers and Wescot (1985) (data not shown).…”

Spatial and Temporal Patterns of Apparent Electrical Conductivity: DUALEM vs. Veris Sensors for Monitoring Soil Properties

“…Others studies documented the comparison between different sensors used for measuring EC a . For example, Abdu et al [13], Urdanoz et al [15] and Saey et al [16] compared two EMI sensors (the DUALEM 1S with the Geonics EM38DD; the DUALEM 1S with the Geonics EM38RT; and the DUALEM 21S with the EM38DD, respectively); Sudduth et al [5] and Fulton et al [17] compared EC a measurements from a non-contact, electromagnetic induction-based sensor (Geonics EM38) to those obtained with a contact sensor (Veris 3100).…”

Limitations to adopting regulated deficit irrigation in stone fruit orchards: a case study

“…As a consequence, the farm manager's irrigation scheduling can not adequately accommodate the variability of soil water properties within the orchard (Boland et al, 2006;Fulton et al, 2011). Fig.…”