Influence of nitrogen rate and time usage on the quality of fodder kale

Abstract

A field study in central Srem (Serbia) evaluated during two seasons the effect of nitrogen (N) fertilizer application (50, 100 and 150 kgha-1) and harvest time (from 70 to 110 days after the seeding) on fodder kale quality. Fodder kale was sown as a second crop in the conditions of irrigation. The goal of study was to evaluate the most important parameters of fodder kale quality (raw proteins and raw cellulose) depending on different nitrogen fertilization and harvest time. The average crude protein content increased (20.78-22,85 %) and the crude cellulose content decreased (15.12-13,96 %) as the nitrogen rates increased, directly due to the higher adoption of nitrogen and indirectly, by increasing the proportion of leaf dry matter in the total yield. The plants used in the first time of harvest had the highest leaf proportion and the highest protein content. Such trends changed in the last harvest time (by postponing the usage) when the crude cellulose content increased because of the leaf biomass reduction. The highest crude protein content (23.10 %) and the lowest crude cellulose content (13.63 %) in the fodder kale dry matter were obtained in the first harvest time (70 days after the seeding) using the highest nitrogen rate (150 kgha-1).

Keywords

• fodder kale
• nitrogen
• harvest time
• quality