For over 20 years, beginning in the 1970s, low-quality irrigation water, characterized by high levels of sodium salts, Electrical Conductivity (EC) of 3 to 5.5 dSm^-1 and Boron (B) concentrations reaching 0.19 to 0.33 mM was utilized to irrigate cotton in Israel's Western Negev region. Management routinely involved pre-plant winter application of gypsum to the area's loess soils, to offset sodicity problems and facilitate infiltration, followed by summer cotton cultivation. Winter rainfall in the area ranges from 200 to 350 mm and some 550 mm of the saline water would be applied during the irrigation season. Recently, as profits from cotton cultivation have declined, alternative crops including peanuts and potatoes have been introduced into the region. These crops are substantially less tolerant than cotton to conditions of salinity and excess B and are irrigated with good quality water (EC = 1.3 dSm^-1, B = 0.02-0.03 mM). In cases where peanuts were cultivated on fields that had previously supported saline irrigated cotton, phenomena including leaf desiccation, and reduced growth and yields of nut pods were observed. We investigated the role of Na, Cl and B retained in the soil and in peanut crops grown in adjacent plots with and without histories of irrigation with the saline water. Each pair of plots had identical soil characteristics (texture, hydraulic properties). Soil was sampled at the beginning and end of each cropping season and saturated paste EC (ECe) and B were analyzed as a function of depth to 120 cm. Leaf samples from peanut plants were taken 5 times during the growing periods and tested for accumulated salts and B. General salinity of the soil was similar at the beginning of the seasons for the plots with saline irrigation water history and for those without up to 90 cm depth. Deeper samples indicated higher salinity (ECe = 5 dSm^-1) in the fields with saline irrigation history than for those without (ECe = 2 dSm^-1). At the end of the growing seasons, these differences were reduced. Boron concentration in the saturated paste extract along the profile of soils with saline irrigation history ranged from 0.11 to 0.19 mM (Saturated paste B) whereas B concentration in the other soils was in the range of 0.03-0.05 mM. Plant matter Cl and Na content were the same for most of the growing period. At the end of the season, slightly greater Cl and Na was found in plants grown in plots with saline irrigation history. Boron content of plant leaf matter in the plots with history of saline irrigation water was significantly greater as it reached 150-250 mg kg^-1 dry matter compared to 50-90 mg kg^-1 dry matter for plants in the plots with no such history. Vegetative biomass production was 21% lower for plots with saline irrigation history compared to the other plots. Pod yield for peanuts was 38% lower in the plots where saline water was historically applied. Boron concentration in soil solution was simulated using a competitive adsorption model. Results indicate that, while Cl is readily leached out of the root zone by winter rains and the appropriate management of good quality irrigation water, B is sorbed to soil components (clays and organic matter) and remains in the soil at rather high levels. Boron accumulated over the years in the soil remains available for desorption into soil solution, and is taken up into the plants where its toxicity is realized. An analysis of the extent of B retention in soil and predictions regarding the amount of time and management options needed to bring B low enough that production of relatively sensitive crops will not be negatively effected are presented.