Simple in situ approaches for determining the timing, depth and magnitude of preferential flow

Development of simple, cost effective techniques for determining the occurrence, depth and magnitude of preferential flow is important for land managers to improve agricultural production and reduce the risk of agrochemical mobilisation to shallow groundwater. Preferential flow is difficult to detect and quantify as it varies both spatially and temporally, such that it is commonly measured in the laboratory in which artificial boundary conditions are imposed. This manuscript outlines a series of simple, mostly in situ approaches for determining the timing, depth and magnitude of preferential flow events.