Properties of red clover in monoculture and in mixtures under the influence of nitrogen fertilization

Abstract

The aim of this research was to determine the production properties of red clover cultivated in monoculture and in mixtures with perennial ryegrass during two years with application of fertilizer in different rates of N. The experimental factors were two mixtures of perennial ryegrass and red clover arranged in different proportions of 70:30 (30CP), 50:50 (50CP) and monoculture of red clover (100CP). N was applied as ammonium nitrate (34% N) in three different levels: 0, 50 and 100 kg N ha-1. After each cut, the botanical composition was studied, the herbage production parameters and crude protein content were analysed. The share of red clover in the crop had a significant effect on all of the studied properties except for the leaf : stem ratio and leaf surface. Higher proportion of red clover increased yield, plant height, specific leaf area (SLA) and leaf area index (LAI). The height of red clover plants and LAI were higher in monoculture than in mixtures by 12% and 46%, respectively. The crude protein content was higher in mixtures than in pure crop by 8%. N fertilization reduced the yield of red clover, and increased other production parameters as well as the crude protein content.