Proximate analyses of roots (to plow depth) and stubble in one-, three-, and five-year-old sods, considered in relation to sequence effects as judged by the nitrogen absorption of the first two wheat crops after each age of sod, indicated the nitrogen content of the hay crop residues to be the dominant influence. Alfalfa was much superior to the grasses, a result apparently of the higher quantity of nitrogen returned to the soil and of the narrower C:N ratio in its residues. Timothy led the grasses, contributing the highest quantity of nitrogen in residues with the lowest percentage of crude fibre and the narrowest ratio of crude fibre to nitrogen-free extract. Brome contributed more residual nitrogen than western rye, but was slightly inferior in sequence effects.
Effect of residual nitrogen and fertilizer nitrogen on sugar beet production in Finland
