Alfalfa (Medicago sativa L.) leaves and stems contain different proteins and nitrogen concentration in different stages of growth. The objective of this study is to determine the dynamic of nutrient accumulation of total nitrogen and proteins in leaves and stems. The experiment was conducted in three slopes, on three regions in the Republic of North Macedonia (Tetovo, Skopje and Ovche Pole). Chemical analysis of total nitrogen and proteins were obtained from first, second and third slope. Modern techniques have been used for analyzing the protein activity of plant material in multiple measuring points. Significant differences are found in the production of total nitrogen and proteins between the locations in Tetovo region on one side, and Skopje and Ovche Pole on the other side. It shows that Tetovo region has better conditions for producing alfalfa protein. Alfalfa is a culture that is rich in high nitrogen and protein content in the Tetovo region, which is correlated with the amino acid composition, resulting in a high biological value. Therefore, alfalfa is the dominant forage crop and active diet culture with high applicability to the bio-diet. Proteins are the most abundant biomolecules in plants and other organisms. Protein macromolecules make up half of the dry matter in the plant cell. The plant cell contains many different proteins with a specific function. Proteins contain the most important property - biological specificity, so the individuality of each organism is conditioned by the type of protein it is made of. Proteins have a specific structure that is found in their biological activity. Proteins are the most important components in the plant cell. Nitrogen is one of the many compounds important for plant life processes and its role in physiological processes in plants is quite large. The needs of certain plants for nitrogen are different. Nitrogen in plants is important in the composition of proteins, nucleic acids, coenzymes, alkaloids, some pigments and other compounds. Accordingly, the nitrogen in plants exists as non-protein and protein nitrogen, found in the protein component. It can only enter the plant cell if it is reduced to ammonia. This scientific research paper provides a comprehensive analysis of the nitrogen and protein composition of alfalfa grown in the Skopje, Tetovo and Ovche Pole region. The results of this research, represent the first full and complete overview of alfalfa (Medicago sativa L.), with its protein composition, which would be of great importance for the further cultivation of this forage crop. Scientific evidence has shown that the Tetovo region has a higher advantage over the Skopje and Ovche Pole region in terms of nitrogen and protein content, which are crucial nutrients in forage crops.
Root Nodule Enzymes of Ammonia Metabolism from Medicago sativa L. as Influenced by Nitrate Levels