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

Abstract

Fertilizer 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.

Broccoli growth in response to increasing rates of pre-plant nitrogen. II. Dry matter and nitrogen accumulation

“…4). These results are similar to Letey et al (1983) and Zebarth et al (1995). A significant nitrogen rate by year interaction for NUE was observed (P 00.0001).…”

“…Researchers have also attempted to measure nitrogen movement and loss in the soil. In these studies, very little nitrate was presumed lost during the growing season, and the majority of soil nitrate remained in the top 15 to 30 cm of the soil at harvest (Letey et al 1983;Kowalenko and Hall 1987;Zebarth et al 1995;Thompson et al 2002b).…”

“…(1 (Cutcliffe et al 1968;Letey et al 1983;Beverly et al 1986;Shattuck and Shelp 1987;Zebarth et al 1995;Sanchez et al 1996;Thompson et al 2002a). Bakker et al (2009) applied seven rates (0 to 400 kg N ha…”

Dynamics of nitrogen and dry-matter partitioning and accumulation in broccoli (Brassica oleracea var. italica) in relation to extractable soil inorganic nitrogen

“…In most studies that included rates up to 336 kg N ha -1 , the response was positive and linear or quadratic (Cutcliffe et al 1968;Cutcliffe et al 1971;Hipp 1974;Letey et al 1983;Beverly et al 1986;Kowalenko and Hall 1987b;Shattuck and Shelp 1987;Tremblay 1989), although two studies found minimal or no yield response to N fertilization (Bracy et al 1995;Kahn et al 1991). In studies that included higher N rates (Greenwood et al 1980;Zebarth et al 1995) or low soil moisture (Beverly et al 1986), a maximum yield response was found beyond which yield declined with additional N applied.…”

“…Generally, N-fertilization studies have also shown that broccoli plants are efficient at accumulating N. In studies using N-fertilizer rates up to 250 kg ha -1 , the crop accumulated more N than was applied as fertilizer (Magnifico et al 1979;Letey et al 1983;Kowalenko and Hall 1987b;Shelp and Liu 1992;Zebarth et al 1995). Zebarth et al (1995) applied N-fertilizer at rates up to 625 kg ha -1 and found that N accumulation by the crop was maximized when about 500 kg N ha -1 was applied and ranged from 345 to 465 kg ha -1 , depending on the cropping season.…”