Cabbage Plant Responses to Nitrogen Fertilization¹

Abstract

Abstract Nitrogen fertilization may affect the yield components and quality attributes of vegetables grown for processing. The objective of this study was to determine the effects of N fertilization systems on cabbage ( Brassica oleracea L. Capitata group) grown for kraut. The concentrations and contents of nitrate‐N and total N in the plants were used to determine the availability of N and uptake of N from the soil and/or fertilizer N during the growing season. Urea broadcast at 15 g N/m 2 and worked into the soil preplant was compared to ammonium nitrate applied at a rate of 15 g N/m 2 split into three 5 g N/m 2 applications (banded at planting time plus sidedressed early plus sidedressed midseason) as fertilization systems for cabbage grown under field conditions in 1978 and 1979. The soil was a Lima silt loam (Glossoboric Hapludalf, fine loamy, mixed mesic), a productive soil derived from calcareous glacial till. Plants were spaced 4/m 2 . Tops of four plants grown without fertilizer N contained 12 g N/m 2 at harvest. Fertilizer N applied at 15 g N/m 2 increased the total N in the plant tops to 22 g N/m 2 . This was an increase in plant N equivalent to two‐thirds of the rate of fertilizer N applied. Cabbage plants grown without fertilizer N yielded 4 kg fresh weight/m 2 . Fertilizer N at 15 g N/m 2 , either as urea or ammonium nitrate, yielded 8 kg of heads/m 2 . Fertilizer N at 30 g/m 2 from urea plus ammonium nitrate yielded 10 kg heads/m 2 . Plants grown with fertilizer N had a lower percentage of dry weight in the heads, and had higher percentages of burst heads and heads with tipburn than heads of plants grown without fertilizer N. Thus, fertilizer N increased the yield but decreased the quality of cabbage heads grown for kraut.