Relationships and Spatial Structure of Soil Physical Properties in a Ten-Year Corn-Cotton Rotation Field

Introduction

Ground and surface water pollution stemming from the application and transport of nutrients, pesticides and other contaminants remains a major environmental challenge (Almasri and Kaluarachi, 2008, Johnson, 2001; Novak et al., 1997; Radosevich et al., 1993). This is a key issue, particularly in the Mississippi River Basin where nutrient and pesticide occurrence in both surface and groundwater is widespread (Devine and Dorfman, 2008; Kingsbury et al., 2014). The management of this problem requires understanding the movement of water and chemicals through soil (Ghanbarian-Alavijeh et al., 2010) and accurate estimation of their leaching and runoff potential.

Conventionally, measurement of soil properties from few sampling points on plot scales are generalized to watershed scales. However, the extrapolation from plot to larger land scales has limitations, especially when the spatial variability of the soil is high. More so, increasing the number of sampling points often entails huge time and labor costs. As a result, chemical transport models are increasingly used to estimate the magnitude of leaching and runoff and to design remedial solutions (Johnson, 2001; Almasri and Kaluarachi, 2008). To be useful for watershed scale applications, chemical transport models must be parameterized to incorporate the spatial variability of soil properties.