Organic and inorganic nitrogen recovery by white cabbage (Brassica oleracea var. capitata)

Abstract

The response of white cabbage to increasing rates of a mineral fertilizer (0, 90 and 180 kg ha^-1 of mineral nitrogen) combined with increasing rates (0, 20 and 40 t ha^-1) of an organic fertilizer resulting from the composting process (182 days) of the solid fraction of dairy cattle slurry, was assessed throughout a systematically arranged experiment to investigate the effect of this compost on cabbage growth and N uptake, with and without mineral N application. Cabbage yield was strongly related to mineral N application and to compost application in treatments without mineral N fertilizer. The increase on mineral N application from 90 to 180 kg ha^-1 increased cabbage N uptake but not significantly cabbage yield. The application of this compost to cabbage crop is recommended up to 20 t ha^-1, particularly when mineral N is not applied.