ABSTRACT
Summary In spite of the importance of alfalfa for all kinds of livestock, particularly for dairy cattle, the cultivation of alfalfa has not yet expanded in Hokkaido, Japan. A comprehensive research project has been undertaken, based on observations of long-term effects of fertilization on longevity and productivity of alfalfa-orchardgrass mixtures. This report is concerned with (1) the dry-matter production of alfalfa and orchardgrass, cultivars of which were introduced from the U.S.A. and (2) the ratio of alfalfa to orchardgrass and uptake of nitrogen (N), phosphorus (P), potassium (K), calcium (Ga), and magnesium (Mg). The research began in 1960 and is continuing with close communication among coresearchers in Japan, the U.S.A., and the Federal Republic of Germany. Included in the project is the introduction of technical equipment, e.g., band seeder. Experimental results can be summarized as follows: 1. Phosphorus applied as a basic fertilizer was very important for the growth of forages, particularly in the seedling stage. 2. Alfalfa topdressed with K produced a higher dry-matter yield and maintained a higher percentage of alfalfa in the sward, as compared with alfalfa not fertilized with K. 3. Percentage of P in forages decreased gradually and came to indicate a critical level after 10 years. As the result of application of P, however, the dry-matter yield increased and percentage of P recovered to the normal level. The application of P and K was necessary for both the normal growth of forages and the production of a high dry-matter yield. 4. Application of P and K enhanced stand longevity of alfalfa during 20 years. 5. Application of P and K stimulated the activity of N-fixing bacteria and increased percentage of N in forage dry-matter.
