Implications of grass-clover interactions in dairy pastures for forage value indexing systems. 6. Cross-site analysis and general discussion

作者：Chapman David F^*; Crush Jim R; Lee Julia M; Cosgrove Gerald P; Stevens David R; Rossi Laura; Popay Alison J; Edwards Grant R; King Warren M

来源：New Zealand Journal of Agricultural Research, 2018, 61(2): 255-284.

DOI：10.1080/00288233.2018.1442868

• Perennial ryegrass
• cultivars
• white clover
• forage evaluation
• grass-clover interactions
• nitrogen

Herbage accumulation (HA) data from four sites were combined to (1) address the hypothesis that adjustments to the New Zealand Forage Value Index to account for grass-clover interactions are not required and (2) explore the main effects of clover and nitrogen (N) fertiliser treatments on pasture productivity. In summer and autumn, pastures based on mid-season heading ryegrass cultivars consistently supported a greater clover content than pastures based on late heading cultivars. However, the cloverx cultivar interaction was significant in only 2 of 17 HA data sets available for analysis. Thus, the hypothesis is supported. Compared with ryegrass monocultures, mixtures yielded an additional 2.4 (in the Low-N treatment) and 1.2 (High-N treatment) t DM/ha/year. Apparent N transfer from clover to grass was 79 (Low N) and 27 (High N) kg N/ha/year, derived from estimated N fixation efficiencies of 66 (Low N) and 50 (High N) kg N/t clover DM grown.

• 出版日期2018