Bromide and nitrate movement in an irrigated cotton production system

A field experiment was conducted for the purpose of determining the worst-case potential for solute leaching under furrow-irrigated conditions, and to assess the spatial variability associated with solute movement. The experiment was carried out on a Mohall sandy loam soil (Typic Haplargid) within a field of upland cotton with uniformity of all management factors, including fertilizer N and irrigation water. Appreciable amounts of solute movement were measured, with a very high degree of spatial variability. The highest degree of leaching potentials was measured early in the season, when soil water depletions were the lowest and crop root development would not be extended past very shallow regions of the soil profile. The results reinforce the need to split fertilizer-N applications throughout the course of a growing season. -from Authors