The information presented in this poster represents the first-year findings of an ongoing two-year study to assess the efficacy of two nitrogen (N) fertilization and irrigation approaches on tomato yield and quality, and the Nitrate (NO3) Leaching Index (NLI) defined as the ratio of the amount of NO3 in 60-120 cm of soil to the amount in 0-120 cm. Water and N use efficiency (WUE and NUE) were determined for processing tomatoes (Solanum lycopersicum) grown on a Handford Sandy Loam soil, with a pH of 6.7, in the San Joaquin Valley (SJV), California, USA. The experiment was a split-plot design with three replications of irrigation rates (I) as the main factor based on evapotranspiration (ET) scheduling amounts of 74% and 100% of crop evapotranspiration (ETc) and two fertilizer (F) application methods as the subplot factor. The Growers Practice (GP) was seven equal applications of CAN-17 for a total of 201 kg N/ha (180 lbs N/ac) over the growing season, whereas the Soil Nitrate Quick Test (SNQT) approach was to apply 17kg N/ha (15lbs N/ac) whenever the NO3 test strip value was less than 20 ppm. A total of 36 beds with a width of 130 cm x length of 2,700 cm were planted so that each subplot comprised three beds, with the two outer beds used as buffer rows. There were no significant differences in the total yield of all tomatoes (reds, breakers, and green) harvested as a function of either the irrigation (p= 0.79) or fertilizer rates (p=0.12). However, for the fully matured marketable red tomatoes, fertilizer practice had a significant effect (p=0.02), with the GP yielding approximately 30% more tomatoes than the plots subjected to SNQT. There was no interaction effect of F x I on the yield of these red tomatoes. With respect to sugar content, I (p
