Spatial and Temporal Variability of Soil Physical and Hydraulic Properties

Research Findings, Reports, and Publications for this Project

Site-specific farming assumes that fields used for agricultural production are not uniform but rather exhibit large spatial variability in their properties. Knowledge of the spatial variability of soil physical and hydraulic properties is important for precision farming and also for the evaluation of agricultural management practices.

It is well known that soil physical and hydraulic properties vary over space and time from field to field as well as within fields. These variations are affected and controlled by many factors such as vegetation, agricultural management practices, previous farming practices and weather conditions.

Point samples are important contributors to our understanding of the dynamics of a field.  However, collecting soil and other samples is time consuming to acquire and expensive to analyze. In addition, the accuracy of maps developed from point data depends on mathematical models to emulate the spatial variation of the variables of interest. Spatial modeling requires intensive sampling efforts that increase in complexity as within field variation increases. These types of data must be integrated with remote sensing technologies to optimize benefits and reduce costs.

Soil data was collected on grid and transect sampling schemes under various soil conditions, tillage systems, crop rotations and irrigation systems. Spatial and temporal dependency and distribution of soil characteristics will be investigated and assessed using several geostatistical tools, GIS mapping, time series analysis and traditional statistics.