Biological and mineral nitrogen on the grassland
1994
Laidna, T. | Viiralt, R. (Estonian Agricultural University, Tartu (Estonia). Department of Grassland Husbandry and Botany.)
The advantages and drawbacks of legume-grass swards in comparison with grass swards have been studied in numerous experiments. In spite of that these problems will also be of great importance to grassland husbandry of temperate Europe. It is one of the main dilemmas in grassland husbandry: what sources of nitrogen should be preferred - whether nitrogen of fertilizer (grasses) or symbiotically fixed one. The field trial on the pseudopodzolic sandy loam at the Eerika Agronomical Experimental Station of EAU to compare the above mentioned two basic sources of N on grassland was carried out. According to the data there were great differences in the yields of green mass, dry matter and crude protein of legume-grass mixtures, and in the persistence of legume species as the dominant in the sward. The content of crude protein in grass dry matter exceeded the level required for dairy cows in case of all legume-grass mixtures, but it was of necessity to apply approximately 250 kg/ha of mineral N to the grass swards
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