Red clover for silage: management impacts on herbage yield, nutritive value, ensilability and persistence, and relativity to perennial ryegrass

This 6-year experiment quantified the impacts of management factors on red clover yield, persistence, nutritive value and ensilability, and compared these with perennial ryegrass receiving inorganic N fertilizer. Within a randomized complete block design, field plots were used to evaluate a 2 (cultivar, Merviot and Ruttinova) x 2 (alone and with perennial ryegrass) x 2 (0 and 50 kg fertilizer N ha(-1) in mid-March) x 2 (harvest schedule) combination of the factors relating to red clover, and a 2 (harvest schedule) x 4 (0, 50, 100 and 150 kg N ha(-1) for each cut) combination of the factors relating to perennial ryegrass. The early and late harvest schedules both involved four cuts per year, but commenced a fortnight apart. Red clover treatments averaged 14 906 kg dry matter (DM) ha(-1) per year, whereas perennial ryegrass receiving 600 kg inorganic N fertilizer per year averaged 14 803 kg DM ha(-1) per year. There was no yield decline evident across years despite a decline in the proportion of red clover. The early harvest schedule and sowing ryegrass with red clover increased the herbage yield and digestibility. March application of fertilizer N to red clover treatments reduced the annual yield. Early harvest schedule increased and both fertilizer N and sowing with ryegrass decreased the proportion of red clover. Sowing with ryegrass improved the indices of ensilability, but reduced the crude protein content. Both red clover cultivars had similar performance characteristics. A selected red clover-based treatment, considered to exhibit superior overall production characteristics, outyielded N-fertilized perennial ryegrass in mid-season. However, it had poorer digestibility and ensilability indices.