Spatial Analysis of Salt Heterogeneity in a Central Californian Grape Field

Abstract

Grape is one of the major crops produced in California; however, moderate salt concentrations in the soil pore space can affect its growth. Therefore, it is important that the root zone salinity be rigorously monitored and maintained below the threshold limit for grape. Spatial analysis of salt heterogeneity can facilitate site-specific management for the crop. We conducted an electromagnetic salinity survey followed by semivariance modeling and kriging analyses in order to quantify the spatial variability and structure of salt distributions in a central Californian grape field. Soils in the study area had silty clayey texture and the salinity across the root zone remained largely elevated with random variations. The kriging analysis demonstrated a large spatial dependence of salinity that extended beyond a 1000 m radius. The isotropic nature of the spatial correlation structure produced an omnidirectional variogram. The overall salinity levels across the field surpassed the salt tolerance threshold for grape and the spatial analyses identified sensitive zones and their structures that require precise adaptive management.

Geophysical Quantification of Water Percolation Quotient in an Alluvial Agricultural Soil

“…Recently, Cassel (2017) demonstrated the application of electromagnetism for site-specific yield optimization in central California. In another study, Cassel and Sharma (2017) described the application of electromagnetism for spatial analysis of salt heterogeneity in a grape field.…”