Pasture Productivity of Different Species Evaluated Under Grazing in the Central Valley of Chile

Seven irrigated mixtures growing on volcanic ash soil were evaluated during 8 years. Five mixtures of white clover (Trifolium repens) (WC) with: ( I) ryegrass (Lolium perenne) (WC-R), (2) fescue (Festuca arundinacea) (WC-F), (3) orchardgrass (Dacrylis glomerara) (WC­O), (4) orchardgrass-ryegrass (WC-O-R), (S) red clover-ryegrass (Trifolilun pratense) (WC-RC-R), (6) lucerne alone (Medicago saliva) (L), and lucerne-orchardgrass (L-0). Plots were 300 m2 in a complete block design with 3 replicates, grazed individually according to growth at 1S0-200 mm height for treatments with WC and 10% bloom for L. Pasture availability and ungrazed residues were evaluated by cutting samples at ground level. Variable number of heifers were used according to availability, all replicates were grazed simultaneously. The number of grazings per year ranged from 7-9 for WC and from 4- S for L. Herbage production on L was 18-22 t DM/ha, significantly (P<0.0S) higher than WC (9-1S t DM/ha). While WC-R and WC-F were evaluated simultaneously in a different trial during S years with lactating dairy cows in 3 2-ha plots each, WC-R yielded more milk per cow, but the milk production/ha was similar.