Uptake and Utilization of Nitrogen from Organic Fertilizers Influenced by Different Doses of Copper

Copper is a microelement involved in the metabolism of nitrogen compounds in plants. Good utilization of nitrogen from soil and fertilizers by plants requires an adequate supply of copper. The aim of the study was to determine the effect of increasing levels of copper (100, 200, and 300 mg Cu·kg−1 of soil) applied together with various organic fertilizers (cattle manure, chicken manure, and spent mushroom substrate) on nitrogen content and uptake by cocksfoot (Dactylis glomerata L.) and the coefficient of nitrogen utilization from organic fertilizers. The pot experiment was carried out in three growing seasons (May–September) in greenhouse, and in this cocksfoot was grown and harvested four cuts in each year. Copper and organic fertilizers were applied once in the first year before sowing cocksfoot, and the after-effect was investigated in the second and third years. Application of different amounts of copper did not influence the nitrogen content in the biomass of cocksfoot. At the same time, soil application of this micronutrient in the amount of 100 mg Cu∙kg−1 of soil caused an increase in nitrogen uptake in the biomass of cocksfoot. Application of 100 and 200 mg Cu·kg−1 of soil caused an increase in the coefficient of nitrogen utilization from the organic fertilizers, which was highest effect in the case of cattle manure. All of the organic materials used increased the content of nitrogen and its uptake by cocksfoot, but the greatest effect was noted following application of chicken manure. The study showed no synergistic or antagonistic relationships between copper and nitrogen.