Effekt der Sorte und Schnittfrequenz auf die Rohprotein-, Lysin- und Methioningehalte und -erträge der Blattmasse von Luzerne

Besides the use of legumes as cover crops, forage legumes are a potential protein-rich roughage. However, since the stems contain more fiber and less protein, it is of interest to harvest only the leaves. Two trials were conducted to find out, how crude protein, lysine and methionine content and -yield of alfalfa (Medicago sativa L.) are affected by variety and cutting frequency. Eight varieties were cultivated in a randomized block design and harvested four times in two years (variety trial = VT). Two of the varieties were additionally cultivated to be harvested five times (cutting trial = CT). After harvest, leaves and stems were separated. Crude protein content of all samples as well as lysine and methionine contents of the leaves of the two varieties were determined. In the VT, the crude protein content of the leaves differed significantly between the varieties (30.4 - 31.6 g 100 g^-1 DM). Crude protein and amino acids contents were highest at the second cut. The leaf yield and therefore also the crude protein and amino acid yields were higher in the second year and decreased from the first cut to the fourth cut. In the CT, higher crude protein and amino acid contents were found in the plants that were cut five times. However, when plants were cut five instead of four times, crude protein and amino acid yields over all cuts did not differ between the two cutting regimes.