The effects of nitrogen and potassium fertilization on the yield and quality of orchard grass grown on arable land: I. Yield and content of some nitrogen coumpounds

摘要

During a three-year experiment on arable land with very good rye soil complex the influence of different nitrogen (60; 120; 180; 240; and 300 kg N/ha) and potassium (100 and 200 kg K/ha) levels on the yield, fertilization effectiveness as well as its influence on the content of total nitrogen, protein nitrogen and nitrate nitrogen in orchard grass were studied. Nitrogen and potassium were used in three equal doses: before vegetation and after the first and second cuts. Three cuts were harvested during each year. The dose of 240 kg N/ha was reported to be optimum in the conditions of the investigation. Applying potassium in a dose exceeding 100 kg K/ha was ineffective. A significantly high effectiveness of 1 kg N and high nitrogen utilisation was observed. The applied fertilization did not lower the fodder quality in respect of accumulation of toxic nitrogen forms. Neither the content of N-NO_3 nor the non-protein nitrogen exceeded the optimum amounts accepted by nutritionists and biologists.