Fertilizer Application and Irrigation Management of Broccoli Production and Fertilizer Use Efficiency1

Abstract

AbstractFertilizer and irrigation must be managed for efficient resource use and preservation of environmental quality as well as maximum production. Two furrow irrigation experiments growing broccoli (Brassica oleracea) were conducted. The first consisted of three N rates (90, 180, and 270 kg/ha), two irrigation treatments (replenishment of water lost by evapotranspiration and evapotranspiration plus 30%), and two N application procedures (application to the soil and in the irrigation water) on a sandy loam soil (coarse‐loamy, mixed, thermic Typic Xerofluvent). Plant growth increased with increasing N application. For a given N application, there was higher average production with the lesser amount of water application. The method of N application had very little effect on production under the lower irrigation treatment, but production was consistently higher for N application with water rather than to the soil when the higher water application treatment was used. The ratio of N in the plant to N applied decreased with increasing N application, decreased with higher water application, and decreased with application in the irrigation water as compared to soil application. The second experiment consisted of two N rates (115 and 225 kg/ba) and two N application procedures (application to soil and in the irrigation water) on a loam soil (fine‐loamy mixed, thermic Calcic Haploxeroll). Yield and N uptake were significantly higher with 225 as compared to 115 kg/ha of N. Conventional preplant and side‐dress N application to the soil resulted in significantly higher broccoli head yield than injecting N in the irrigation water. Leaching of N was not a factor under the experimental conditions.