Strawberries in the Santa Maria Valley are grown on beds 25.2 cm wide with four rows of strawberries and two lateral drip tapes. Previous strawberry production was on beds 15.7 cm wide with two rows of strawberries and one lateral drip tape. The two strawberry production systems were evaluated on several grower fields for water emission uniformity, soil moisture, and soil salinity. The salinity was evaluated for placement in the bed, type of salts, and nitrate concentration. At one side, the effect of banded slow-release nitrogen fertilizers as a source of nitrogen in addition to that applied through fertigation was investigated. Results showed that the EUs ranged between 80% and 96%, with an average of 89%. A variety of distributions were found for soil moisture, soil salinity, and soil nitrate, depending on the water and fertilizer management and time of sampling with respect to irrigation and fertigation. Distributions of soil moisture content made 3 to 4 days after an irrigation indicated excessive drying of the soil between irrigations. Distributions of soil salinity revealed high salt concentrations near the drip tape, where leaching was insufficient, and relatively low concentrations near the tape, where leaching was adequate. Nitrate concentrations in and below the rootzone were smaller where no slow-release fertilizers were used.
Effects of Foliar Application of Urea and Urea-Formaldehyde/Triazone on Soybean and Corn Crops
