Analyses of saturation extracts of soil samples from six treatments of a long-term fertility trial, in which irrigation was by gravity flow into permanent furrows, indicated considerable retention of salt within the root zone. Most of the salt retention was within the 0- to 8-foot depth, but some extended into the 10- to 15-foot depth. Salt concentrations within the root zone were correlated with leaching fractions. Analyses of samples from below the 10-foot depth showed that drainage waters had much lower salt contents than the water of the root zone, and suggest that the drainage waters effectively by-passed soil volumes of higher salt concentration in the root zone. Because of salt retention in the root zone of the permanent-furrow gravity-flow irrigation system, higher leaching fractions are required to prevent accumulation of adverse salt concentrations than would be the case for many other systems.