Brendan R. Cullen
Volume 74 Numbers 7 & 8 2023
Special IssueAGA 2023 – Pasture legumes for sustainable productive systems
Brendan R. Cullen
Legumes have underpinned the New Zealand pastoral-based economy for over 100 years. White clover remains the most widely sown, but specialist red clover based pastures are providing high quality feed for fattening livestock in wetter regions of the country. In the drier east coast, lucerne management has been refined based on crop physiology principles. This has allowed earlier lambing, leading to transformational change on-farm. Subterranean clover remains the dominant annual legume used. Successful integration of legumes on-farm has required understanding of the genotype by environment by management interactions.
CP22237 Abstract | CP22237 Full Text | CP22237PDF (1.8 MB) Open Access Article
CP22299Reducing enteric methane of ruminants in Australian grazing systems – a review of the role for temperate legumes and herbs
Temperate low methane (CH4) yielding legumes and herbs can reduce enteric methane, but greenhouse gas emissions at a system level need to be considered. This review identified several pasture species with anti-methanogenic properties, with biserrula having the most potential to reduce enteric CH4. However, a case study demonstrated that emission intensity of biserrula was similar to that of subterranean clover but higher than that of lucerne. An opportunity exists to formulate pasture mixtures to reduce CH4 and increase livestock production.
CP22299 Abstract | CP22299 Full Text | CP22299PDF (1.6 MB) Open Access Article
CP22301Strawberry clover (Trifolium fragiferum): current status and future role in Australian agriculture
Strawberry clover has been suggested as an alternative perennial pasture legume for temperate regions of Australia. We review its taxonomy, morphology, native distribution and subsequent transfer to Australia. We map the suitability of strawberry clover for perennial pasture systems, with reference to future climates, and identify future research foci. Strawberry clover is unlikely to become a dominant pasture legume species in Australia but could be used in a wider range of environments.
CP22301 Abstract | CP22301 Full Text | CP22301PDF (8.6 MB) Open Access Article
CP22199Hard seed breakdown patterns of serradella (Ornithopus spp.) in two contrasting environments of south-eastern Australia
Serradella has many advantages as a pasture legume, however persistence and productivity in permanent pastures can be inadequate. This study quantified seed softening of serradella species in comparison with subterranean clover in the Southern Tablelands and Central Slopes districts of eastern Australia. Diverse patterns of seed softening were observed among serradella cultivars, in contrast to subterranean clover. Implications for pasture establishment of serradella in high rainfall zone permanent pastures is discussed.
CP22277Legume persistence for grasslands in tableland environments of south-eastern Australia
This study evaluated the stability and persistence of a range of legume species and cultivars to identify viable options for grasslands of south-eastern Australia. Yellow and French serradella, white clover and subterranean clover were identified as priority species because they are already, or are close to being, viable options for use in grasslands. An increased focus on phenology and seed characteristics is suggested to improve the persistence of white clover and serradella in grasslands.
Profitability of livestock production over summer–autumn in the temperate environment of south-eastern Australia could be improved by including legumes in pastures that are persistent, productive and of high nutritive value. Evaluation of a range of legume species and cultivars showed that lucerne remained the most reliably productive warm-season option where soil conditions support it. Talish, Caucasian and strawberry clovers were persistent and of high nutritive value, warranting further evaluation in special-purpose warm-season pastures.
CP22406 Abstract | CP22406 Full Text | CP22406PDF (2 MB) | CP22406Supplementary Material (697 KB) Open Access Article
CP22222Variation in flowering time and flowering date stability within a cultivar of French serradella
Serradellas (Ornithopus spp.) are a novel legume option for the permanent pasture environments of south-eastern Australia. This paper investigated evidence of variation in flowering time characteristics within a widely used cultivar of French serradella. We recommend that new cultivars of serradellas be evaluated for flowering time characteristics in their target environment(s) to assess whether the cultivars are suitably adapted to these environments. This is essential to maximise production, feeding value and facilitate effective grazing management.
CP22222 Abstract | CP22222 Full Text | CP22222PDF (2 MB) | CP22222Supplementary Material (361 KB) Open Access Article
Serradellas are promising alternative legumes to subterranean clover for permanent, temperate pastures. However, many cultivars exhibit unstable flowering dates. This is a risk for seed production and persistence. Later maturity was particularly associated with need for long exposure to the vernalisation treatment to hasten flowering. Stable flowering is more likely when a cultivar has components of its vernalisation requirement that are not satisfied before autumn ends to prevent premature flowering, and a photoperiod response in spring that overrides any unmet vernalisation requirement.
CP22366 Abstract | CP22366 Full Text | CP22366PDF (1.4 MB) | CP22366Supplementary Material (381 KB) Open Access Article
The legume shrub/tree leucaena is highly regarded as a tropical cattle fodder, although it is considered an environmental weed in many parts of the world. In an Australian first, we report the successful creation of triploid leucaena germplasm through interspecific hybridisation. These give rise to sterile adults (without seeds), mitigating weed risk. Over 2000 hand-crosses between 45 different combinations of diploid and tetraploid leucaena species have created a cohort of sterile plants to evaluate for field performance.
CP22281 Abstract | CP22281 Full Text | CP22281PDF (2.6 MB) | CP22281Supplementary Material (445 KB) Open Access Article
Freshly harvested seeds of temperate annual pasture legume species have physiological dormancy (PD), which delays the growth of the next generation and is thus an impediment to speed breeding. We report on the development of PD breaking methods that rapidly overcome PD of freshly harvested seed. The rapid breaking of PD assists the speed breeding of annual pasture legumes by making it less laborious and time-bound than previous methods.