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Context: Data are lacking on the effects of selected endophytes of perennial ryegrass (Lolium perenne L.) on ryegrass persistence. Aim: We aimed to determine the impact of Epichloë endophyte on the persistence of mid- and late-heading perennial ryegrass cultivars. Method: Two mid-heading (Samson, Bronsyn) and two late-heading (One50, Rohan) cultivars, infected with selected endophytes (AR37, nea2/6) or with standard toxic endophyte, were established in a replicated plot study grazed by cattle in a subtropical environment of the upper North Island of New Zealand. Persistence characteristics were quantified at least five times per annum, over 4 years. Key results: Endophyte strain had an effect on persistence; infection with standard endophyte resulted in higher ryegrass ground cover percentage, ryegrass content in pasture dry matter and autumn yield than infection with nea2/6 on many occasions, and with AR37 on some occasions. There were negligible impacts on ryegrass tiller density or nutritive value. Trends were dominated by the main effect of endophyte; interactions with heading date were inconsistent. Conclusions: Cultivars were more persistent when infected with standard endophyte than with selected endophytes, although persistence declined over 4 years for all cultivars and irrespective of heading date. Implications: Reliance on selected endophyte is unlikely to prevent persistence decline of perennial ryegrass in a subtropical environment. Other strategies will be required to maintain the persistence of high-quality pastures based on perennial ryegrass. We determined the impact of endophyte strain (standard toxic endophyte, selected strains nea2/6 and AR37), on the persistence of four perennial ryegrass cultivars. Standard endophyte resulted in greater persistence than the selected endophytes, with higher ryegrass ground cover percentage and content in pasture dry matter by the end of the study, and higher herbage yields in autumn. Persistence declined over 4 years for all cultivars, regardless of endophyte. [ABSTRACT FROM AUTHOR]

Context: Data are lacking on the effects of heading date of perennial ryegrass (Lolium perenne L.) on ryegrass persistence. Aim: We aimed to determine the impact of heading date on perennial ryegrass persistence. Method: Two mid-heading (Samson, Bronsyn) and two late-heading (One50, Rohan) cultivars, infected with Epichloë endophytes (AR37, nea2/6 or standard toxic), were established in a replicated plot study grazed by cattle in a subtropical environment of the upper North Island of New Zealand. Persistence characteristics were quantified at least five times per annum, over 4 years. Key results: Late-heading cultivars had higher yield, nutritive value, perennial ryegrass content in pasture dry matter, ground cover and tiller density than mid-heading cultivars. There were large seasonal impacts on all ryegrass characteristics, with a major decline over summer and recovery during late autumn into early spring, with less recovery in the final year. Overall, there was a strong linear decline in ryegrass content measured during spring (2018–21). Conclusions: The two late-heading cultivars were more persistent than the two mid-heading cultivars, although persistence declined over 4 years for all cultivars. Implications: Results support industry recommendations of choosing late-heading cultivars for improved pasture quality and persistence. We determined the impact of heading date on persistence of perennial ryegrass cultivars infected with a range of endophytes, in a plot study grazed by cattle. The two late-heading cultivars were more persistent than the two mid-heading cultivars, with higher yield, nutritive value, perennial ryegrass content in pasture dry matter, ground cover and tiller density, although persistence declined over 4 years for all cultivars. [ABSTRACT FROM AUTHOR]

This article reviews nine soil carbon interventions to reduce soil carbon losses or increase stocks in grazing management systems, using their potential application in Aotearoa New Zealand (A‐NZ) as a case study. The interventions are classified into three strategies: (1) increasing carbon inputs through deep‐rooting and diverse species grasslands, reducing forage cropping and deferred grazing management; (2) increasing protection of carbon stocks by water table management on organic soils, reducing cropping on organic soils, full inversion tillage grassland renewal, the addition of clay minerals and enhanced rock weathering and (3) the adoption of integrated systems including establishing tree clusters into grasslands and agroforestry. We estimated the land area where these interventions could realistically be implemented in A‐NZ and assessed their potential impact on mitigating national overall agricultural greenhouse gas emissions. The potential impact of each intervention ranged from <1% to 2.5% of national agricultural greenhouse gas emissions over 20 years. However, confidence in these approaches is hindered by a lack of research data where these approaches have been tested for different soil types and conditions. Notably, water table management, which reduces carbon loss from organic soils, was the only intervention that could achieve moderate, short‐ and long‐term impacts with a confidence level assessed as 'likely'. We conclude that reducing further soil carbon losses and achieving modest increases in soil carbon stocks are possible but will require economic and political incentives that encourage the integration of multiple interventions at the farm scale. [ABSTRACT FROM AUTHOR]

Background: Perennial ryegrass (Lolium perenne) in New Zealand pastures is typically infected with the mutualist Epichloë fungal endophyte. This endophyte assists the plant in resisting biotic and abiotic stresses, but the standard strain of endophyte is toxic to livestock. Elite ryegrasses with selected endophytes have been developed to provide protective properties to the grass plant and lessen or eliminate the negative impacts on livestock. Methods: Using immunology and molecular techniques, the presence of endophyte infection and endophyte strain in ryegrass tillers was determined for 24 dairy pastures sampled for up to 7 years in regions of the North and South Islands. Results: In general, infection levels were high and showed small increases over time. Some pastures failed to reach 70% infection. The sown, selected endophytes were the dominant endophyte strains present and these were stable over time. Standard endophyte was the primary nonsown endophyte, and while generally low and so of little importance, it increased over time and for some pastures, this would have been detrimental to livestock. Pasture establishment technique influenced the level of contamination. Conclusions: Results reinforce the importance of following best practice procedures in the seed industry and on‐farm. Researchers should monitor trials for contaminating nonsown standard endophyte. [ABSTRACT FROM AUTHOR]

Context: Tagasaste (Cytisus proliferus) has potential to supplement pasture production in steep-hill country and increase pasture resilience. Aims: To (1) quantify production of edible dry matter (EDM) of pruned 2-year-old tagasaste shrubs and branches from unpruned 10-year-old tagasaste trees, and (2) determine the effect of proximity of the 10-year-old tagasaste trees on selected pasture species established as spaced transplants. Methods: A site was established on the eastern coast of the North Island of New Zealand on steep-hill country (>20° slope). Tagasaste and pasture species production was measured over 3 years. Results: Tagasaste shrubs produced an average of 2.7 kg EDM shrub−1 year−1 and a tree branch produced 129 g EDM year−1. The metabolisable energy content of tagasaste branches averaged 10.0 MJ kg EDM−1, the crude protein content ranged from 18% to 27% and neutral detergent fibre content averaged 39%. Branch diameter and length were poor predictors of EDM branch−1. There was no effect of increasing proximity to tagasaste on DM production of the resident pasture. Effects of increasing proximity to tagasaste on the growth and survival of selected pasture species are reported in a companion paper. Conclusions: Edible-DM production was much greater from shrubs than tree branches and it was not possible to predict branch EDM from branch diameter or length. Implications: A tagasaste silvopasture is likely to be more productive if tagasaste is managed for grazing in situ than if using mature trees for harvesting of branches for browse. The production of edible dry matter (EDM) of 2-year-old tagasaste shrubs averaged 2.7 kg shrub−1 year−1 on one steep, north-facing hillside on the eastern coast of New Zealand. This equated to the production of 2.2 t EDM ha−1 year−1 at spacings of 3.5 m (816 shrubs ha−1), with a metabolisable energy content averaging 10.0 MJ kg EDM−1. In low-producing (<4 t DM ha−1 year−1) pastures on drought-prone, steep-hill country, inclusion of tagasaste could increase edible forage production by 50%. [ABSTRACT FROM AUTHOR]