Field experiments were made over 2002-2004 at the Experimental Station of the University of Technology and Life Sciences in Mochełek (53o13’ N; 17o51’ E) on very good rye complex soil. The aim of the research was to define the effect of nitrogen fertilization of non-papilionaceous plants grown in stubble intercrop on the qualitative characters of green matter determining its applicability for cattle nutrition. Nitrogen fertilization increased the content of N-NO3 in the dry overground matter of tansy phacelia, sunflower and oilseed radish; however, even the application of 90 kg·ha-1 N did not result in exceeding its permissible concentration in cattle feed. Increasing the nitrogen dose did not result in significant changes in the content of crude fibre, potassium, calcium and magnesium in the dry overground matter of plants. The plants researched contained the amount of crude fibre, phosphorus, calcium and magnesium in the dry overground matter adequate for the purpose of animal feed, but an excessively high content of potassium.

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