Meat and bone meal (MBM) can be a viable alternative to natural, organic and mineral fertilizers because it is rich in nitrogen (N), phosphorus (P), calcium (Ca), micronutrients and organic matter that can be recycled back into agricultural land. The aim of this study was to determine optimal fertilization levels, including MBM, for winter oilseed rape (Brassica napus L.). Meat and bone meal was applied at three increasing doses (1.0, 1.5 and 2.0 t ha-1) without or with supplemental mineral N (40 and 79 kg N). The macronutrient (N, P, K, Ca and Mg) content of winter oilseed rape seeds and straw, and macronutrient uptake by aerial biomass were evaluated. A small-scale field experiment was conducted at the Agricultural Experiment Station in Tomaszkowo (northeastern Poland) in two growing seasons of 2015/16 and 2016/17. The experiment had a randomized block design, and it was established on brown soil developed from loamy sand. Changes in the uptake of the analyzed macronutrients and their concentrations in winter oilseed rape seeds and straw were affected by fertilization and weather conditions. One ton of MBM supplied 79 kg N and 45 kg P to the soil. Supplemental mineral N was applied before sowing to widen the narrow N/P ratio in MBM, which had a beneficial influence on the mineral composition and macronutrient uptake by the aerial biomass of winter oilseed rape. Macronutrient (N, P, Ca and Mg) uptake by plants was highest in the treatment with the lowest MBM dose (1.0 t MBM ha-1) supplemented with 79 kg mineral N (50% N from mineral fertilizer and 50% N from MBM). In the above treatment, NPK fertilizer rates corresponded to those in the control treatment. The results of this study indicate that MBM applied at 1.0 t ha-1 meets the P and N requirements of winter oilseed rape in 100% and 50%, respectively. Therefore, the recommended mineral N fertilizer rate for winter oilseed rape can be reduced by 50%.

25.3.2020