The Influence of Competition Between Festuca arundinacea Schreb. and Trifolium pratense L., Grown in Simple Mixtures, on the Quality of the Fodder

Abstract

The aim of this research carried out in the period 2021–2023 was to analyse the influence of competitiveness between Festuca arundinacea Schreb. and Trifolium pratense L., cultivated in simple mixtures, on the quality of the fodder obtained, under the conditions of the northern Romanian forest steppe. In the experiment organized at the Ezăreni Student Research and Practice Station of Iasi University for Life Sciences, at an altitude of 117 m, with coordinates 47°07′27″ N latitude and 27°30′25″ E longitude, on a cambic chernozem soil, with 2.40% humus, 0.178% Nt, 26 ppm PAL and 242 ppm K in the 0–30 cm layer, two factors were studied, namely the cultivation system used, with five graduations: a1—Festuca arundinacea Schreb. (100%—control); a2—Festuca arundinacea Schreb. (75%) and Trifolium pratense L. (25%); a3—Festuca arundinacea Schreb. (50%) and Trifolium pratense L. (50%); a4—Festuca arundinacea Schreb. (25%) and Trifolium pratense L. (75%); and a5—Trifolium pratense L. (100%), and mineral fertilization, with five graduations, respectively: b1—unfertilized (control), b2—N50P50; b3—N75P75; b4—N100P100; and b5—N150P150. The obtained results showed that the process of interspecific competitiveness was greatly influenced by the percentage of participation in the sowing norm of the species in the mixture and the biological peculiarities of the species under study, as well as the climatic conditions specific to each agricultural year, with consequences for the quality of the feed. The crude protein quantity (QCP) obtained in the mixture of Festuca arundinacea Schreb. (25%) and Trifolium pratense L. (75%), fertilized with N150P150, was higher by 788.7 kg·ha−1 than that in the control variant, represented by the Festuca arundinacea Schreb. species (100%), unfertilized. The lowest values of NDF (neutral detergent fiber) and ADF (acid detergent fiber) were recorded in the variants where the Trifolium pratense L. species was present and low doses of mineral fertilizers were used, determining a better quality of the forage. In the third year of vegetation, relative forage quality (RFQ) had values of 113.7 in the variant represented by the mixture of Festuca arundinacea Schreb. (25%) + Trifolium pratense L. (75%), unfertilized, and only 91.2 in the variant represented by the Festuca arundinacea Schreb. species (100%), fertilized with N150P150.