Mljekarstvo (Dec 2009)
Productivity and botanical composition of pasture under grazing and fertilizing
Abstract
Environmental and economic factors in milk and meat production increase a use of legumes and grass-legumes mixtures, with zero or minimum mineral N as an alternative to grass monoculture withhigh rate of mineral N. The research aimed to examine the effect of N application (0-N0 and 150 kg ha-1 year-1-N150) and rotational grazing by cattle (C) and sheep (S) on grassland productivity and botanical composition. On the average, 5.3 % higher total dry matter (DM) yield was obtained under S than under C. With N0 was achieved >80 % of N150 DM yield. The grazing management x N rate interaction was recorded for legumes DM yield and their contribution to total DM yield. N150 decreased both parameters only in S, while differences in these parameters between grazing management obtained only in N0, whereas S was less detrimental to legume growth than was cattle grazing. N150 increased grass DM yield for 29.3 % in comparison to N0. The grazing management x N and year x N interactions were recorded for the grass contribution to total DM yield. Differences in this parameter were found only in N0 where C resulted in higher grass content. There were no significant differences in grass content between years in N0, while in N150 grass content in 2000 was lower than grass content in 2000 and 2002. N0 resulted in 88 % higher DM yield and 139 % higher forbs content in comparison to N150. C resulted in 44 % higher content of dead plant material compared to S.
