The relative strengths of phosphate fertiliser application and white clover cultivar introduction for hill pasture improvement

Abstract

<jats:p>Abstract Combinations of four phosphorus (P) fertiliser rates (0, 8.5, 22.5 or 26.5 kg/ha/year of citrate-soluble P) and three pasture types with different white clover germplasm, 'resident' cv. Huia and cv. Tahora were compared in self-contained, replicated farmlets grazed by sheep over 4 years. Fertiliser increased white clover herbage accumulation (HA) 3- to 4-fold compared with the control treatment, and increased total sward HA by 50%. Introduction of Tahora white clover significantly increased white clover and total sward HA and nitrogen fixation compared with the resident and Huia-sown swards. Sheep liveweight gain was significantly greater in all systems fertilised with P (438 versus 243 kg/ha for the unfertilised control) and in systems sown with Tahora (425 versus 372 kg/ha for resident and Huia). Keywords: phosphorus fertiliser, white clover, cultivars, herbage accumulation, animal production</jats:p>

Quantifying the value proposition for white clover persistence on a New Zealand summer-dry hill-country farm

“…Pastures without white clover had a negligible response to increased Olsen P, while pastures with white clover grew an additional 16-18% dry matter over the year. This compares favourably with the farmlet study of Chapman et al (2017), who recorded 10-20% increases in annual herbage accumulation resulting for clover introduction into southern North island hill country. Table 2.…”

“…The greatest proportional increase in annual herbage accumulation was estimated to be on the south aspects (23-24%) compared to the north aspects (14-16%). This compares favourably with the farmlet study of Chapman et al (2017), who recorded 10-20% increases in annual herbage accumulation resulting for clover introduction into southern North island hill country.…”

“…That study also sought to quantify the potential contribution of legumes to the system in a spatially and temporally explicit way and identified between $800-1600 per hectare benefit from increased legume content in pastures, through greater lamb and cattle productivity. Chapman et al (2017) have also shown significant benefits to white clover introduction Journal of New Zealand Grasslands 82: 199-209 (2020) in southern North Island hill country, in terms of a 14% increase in sheep liveweight gain with in a farmlet study, although the gains they observed from improving soil fertility were much greater.…”