Dry matter yield and nutritive value of four alfalfa varieties associated with white clover, perennial ryegrass, tall fescue and orchard grass

Abstract

THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE FORAGE DRY MATTER (DM) YIELD, THE EXTENT OF NODULATION, NUMBER OF STEMS PER CROWN OF ALFALFA PLANT, NUTRITIVE VALUE AND BOTANICAL COMPOSITION OF FOUR ALFALFA VARIETIES (CUF- 01, JUPITER, MOAPA AND SAN MIGUELITO) ASSOCIATED WITH A GRASS-LEGUME MIXTURE COMPOSED OF WHITE CLOVER, PERENNIAL RYEGRASS, ORCHARD GRASS, AND TALL FESCUE DURING THE YEAR OF ESTABLISHMENT. A FIELD OF EIGHT HECTARES WAS SOWN WITH THE GRASS-LEGUME MIX AND THE FOUR ALFALFA VARIETIES USING A RANDOMIZED COMPLETE BLOCK DESIGN. TOTAL NUMBER OF PLANTS PER SQUARE METER DID NOT DIFFER AMONG THE ASSOCIATIONS CONTAINING THE FOUR ALFALFA VARIETIES THREE WEEKS AFTER EMERGENCE, AND ON AVERAGE THERE WERE 635 PLANTS PER SQUARE METER. DURING THE PASTURE'S ESTABLISHING PHASE, LEGUMES WERE THE HIGHEST (P < 0.005) CONTRIBUTORS TO THE HERBAGE MASS (43.5%), FOLLOWED BY GRASSES (36%), AND UNSOWN SPECIES (20.5%). NUMBER OF NODULES DID NOT DIFFER AMONG ALFALFA VARIETIES FIVE WEEKS AFTER EMERGENCE, AND ON AVERAGE THERE WERE 12.5 NODULES PER PLANT. JUPITER HAD MORE (P < 0.05) STEMS PER CROWN (35.4) THAN CUF-101 (22.5). MOAPA (32.4) AND SAN MIGUELITO (26.0) VARIETIES HAD INTERMEDIATE VALUES THAT DID NOT DIFFER FROM THOSE OF CUF-101 AND JUPITER. PLANT HEIGHT WAS THE HIGHEST (P < 0.001) IN SUMMER (54 CM) AND THE LOWEST IN WINTER (33 CM). THE BOTANICAL COMPOSITION DID NOT DIFFER FOR THE GRASS-LEGUME ASSOCIATIONS, BUT SIGNIFICANTLY (P < 0.05) CHANGED WITH THE SEASON OF THE YEAR. GRASSES WERE MORE ABUNDANT IN SPRING (28%) AND SUMMER (27.3%), AND LEGUMES IN SUMMER (68.9%), AUTUMN (61.1%) AND WINTER (61%), WEEDS IN SPRING (32.1%), AND DEAD HERBAGE IN AUTUMN (18.3%) AND WINTER (18.7%). THERE WERE NO DIFFERENCES AMONG ALFALFA VARIETIES IN THE LEAF TO STEAM RATIOS. ACROSS VARIETIES, HOWEVER, THE STEM WAS THE HIGHEST (P < 0.05) CONTRIBUTOR TO THE TOTAL PLANT MASS WITH 58%. PASTURE NUTRITIVE VALUE DID NOT DIFFER AMONG THE ASSOCIATIONS CONTAINING THE FOUR ALFALFA VARIETIES. THE PERFORMANCE OF THE ASSOCIATIONS CONTAINING THE FOUR ALFALFA VARIETIES DURING THE FIRST YEAR OF PRODUCTION WAS VERY SIMILAR. HOWEVER, THE ASSOCIATION CONTAINING THE JUPITER ALFALFA VARIETY YIELDED MORE (P < 0.05) HERBAGE DM PER YEAR (33.8 TONS/HA) THAN THE ASSOCIATIONS CONTAINING CUF-101 (29.7 TONS/HA), MOAPA (30.6 TONS/HA) OR SAN MIGUELITO (29.3 TONS/HA) VARIETIES, WHICH MAKES IT A VALUABLE MATERIAL TO USE IN MIXED GRASS-LEGUME PASTURES.