Selected Soil Physical Properties and Implications on Water Management System in Northeast Florida

Abstract

Selected soil physical properties at varying depths in a cultivated Alfisol in northeast Florida were studied using classical and geostatistical techniques. The objective was to investigate the variation in the physical properties among and within the sampling depths and understand its implications to field water management in the area. Seventy soil core samples were collected in a grid sampling scheme from five depths: 22.5 cm, 45 cm, 67.5 cm, 90 cm, and 120 cm. Particle size distributions, bulk density (D b ), and saturated hydraulic conductivity (K s ) of the soil samples from each depth were measured and statistically compared among depths, and the spatial variation of properties within each sampling depth was determined. Clay content and D b increased significantly with increasing depth, whereas the K s decreased. The K s exhibited the maximum variation in both vertical and horizontal direction, whereas D b was the least variable among the three properties. The semivariogram analysis showed a weak spatial autocorrelation in soil properties within the sampling depths. The results suggested that despite significantly low conductivity and high D b of the soil profile at 120 cm, it was not impermeable enough to restrict vertical water movement as opposed to the general perception of the occurrence of a shallow impermeable layer in the profile and consequent perched water table conditions. The results, therefore, provided a definitive insight into the water table management system in the area, which is important for understanding the irrigation system, its efficiency, and consequent water quality impacts on surface and/or groundwater.

Soil moisture distribution under drip irrigation and seepage for potato production

“…The soil has been classified as sandy, siliceous, hyperthermic Arenic Ochraqualf and belongs to the Ellzey series (USDA, 1981). Soil bulk density was 1.37; 1.42; 1.52 and 1.60 g cm -3 and saturated hydraulic conductivity was 13.10; 13.41; 15.29 and 10.95 cm h -1 ; respectively for soil depths at 0.22; 0.45; 0.67 and 0.90 m (Acharya and Mylavarapu, 2011). The soil particle size was 916 g kg -1 of sand, 37 g kg -1 of clay and 47 g kg -1 of silt.…”

“…Field experiments were carried out at the Hastings Research and Extension Center in Hastings,Florida (2941' 27.58''N,8126'31.37''W). The water table is controlled by the hydrology of a landscape that is only approximately 10 m above sea level (Acharya and Mylavarapu, 2011).…”

Analytical expressions for drainable and fillable porosity of phreatic aquifers under vertical fluxes from evapotranspiration and recharge

“…This area is a low (<10 m above sea level), flat landscape with a naturally shallow water table (<2 m from surface). A locally important crop is potato grown under a WT management system known as seepage irrigation [ Smajstrla et al , 2000; Munoz‐Arboleda et al , 2008; Acharya and Mylavarapu , 2011] wherein the WT is maintained close to the crop root zone by applying water from shallow furrows spaced uniformly at 18–20 m between main lateral ditches (1.5–2.0 m deep) at the edges of fields on the order of 3–15 ha. The flow system in these agricultural fields therefore can be appropriately represented by the Boussinesq equation (i.e., and ).…”

Evapotranspiration Estimation from Diurnal Water Table Fluctuations: Implementing Drainable and Fillable Porosity in the White Method

“…During the crop season, the WT is maintained very close to the surface (≤50 cm) using a network of shallow, open drains and ditches. Detailed descriptions of the field sites, soil properties including soil moisture retention curve parameters, and management practices were reported by Acharya et al (2012) and Acharya and Mylavarapu (2011).…”

“…The estimated λ d and λ f for the Ellzey fine sand series (sandy, siliceous, hyperthermic Arenic Endoaqualfs) present at our field sites (Acharya and Mylavarapu, 2011) are shown as a function of WT elevation in Fig. 2 under both hydrostatic and hydrodynamic (ET > 0) conditions.…”