In the mid-Atlantic region, the combination of high crop value, sandy soils, and the probability of significant in-season rainfall can lead to excessive irrigation and nitrogen applications, resulting in leaching and an adverse impact on groundwater quality. Despite the continued growth in irrigation in the region, there is little research on irrigation management practices that are specifically adapted to these conditions. This study was conducted to characterize current irrigation management practices on ground water quality at field scales, and to collect information and data needed to develop irrigation BMPs suited to humid and intermittent rainfall conditions. In 2002 (a dry year) and 2003 (a wet year) grower's fields were instrumented with commercially available capacitance type sensors to measure near-continuous soil water content at discrete soil depths. Crops monitored were sprinkle-irrigated corn, and drip-irrigated melons and peppers that were grown under plastic mulch. In 2004, this approach was used on replicated drip-irrigated melon plots on University of Delaware facilities to study the impact of three irrigation rates ranging from deficient to excess (50% to 150% of ET). Measurements in 2002 and 2003 on grower's fields showed that most irrigation events resulted in water penetration to at least 1-m depth, but little water uptake at deeper depths. In 2004, data on soil water content at 10, 20, 30, 50 and 70cm were collected from 4 replications of the three irrigation treatments. The first half of the 2004 season was considerably drier than the second half. The variation in measured soil water content between replications tended to be relatively large, while yield differences were relatively small. The capacitance sensors responded well to changes in soil water content due to crop water use and irrigation events; however, the effect of rainfall on soil water content was more difficult to quantify.