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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]

Perennial ryegrass (Lolium perenne L.) is a widely sown pasture species in temperate regions. Under heat and moisture-deficit stress, its production is suppressed and tiller mortality increases, particularly when plants are simultaneously exposed to other stresses such as intense defoliation. We investigated the effects of extended grazing exclusion periods in spring and summer on herbage and soils of rotationally grazed, perennial ryegrass-dominant pastures at a summer-wet site and a summer-dry site in sheep and beef hill country in New Zealand. Treatments comprised 'grazed' (conventional rotational grazing), 'early opening' (grazing exclusion from mid-spring to mid-summer to allow perennial ryegrass to flower), and 'deferred grazing' (grazing exclusion from mid-spring to late summer to allow perennial ryegrass to flower and set seed). At both sites, deferred grazing increased perennial ryegrass tiller density and total vegetation cover, and reduced the abundance of broadleaf species and Pseudopithomyces chartarum spores for up to 15 months after exclusion compared with the grazed control. Herbage production was reduced during the deferred period but there was a growth surge thereafter so that herbage production over the study period was similar in the deferred and grazed treatments. Pasture nutritive values were lower in the deferred than the grazed treatment during the exclusion period but were similar in all treatments by the end of the following winter. In the autumn after deferring, seedlings contributed ~50% of the perennial ryegrass tillers present at the summer-dry site but only ~10% at the summer-wet site, where regrowth tillering of existing plants contributed a high proportion of the perennial ryegrass tillers present. Overall, early opening had few effects on the pasture, whereas deferred grazing had numerous positive effects on the pasture but only short-term effects on soil quality. We investigated the impacts of deferred grazing (livestock excluded from mid-spring to late summer to enable perennial ryegrass to flower and set seed), early opening (livestock excluded from mid-spring to early summer to enable perennial ryegrass to flower) and standard rotational grazing on hill country pastures and soils under beef and sheep grazing. Compared with standard rotational grazing, deferred grazing had positive effects on pasture productivity but only short-term effects on soil quality, whereas early opening had few effects on the pastures or soils. [ABSTRACT FROM AUTHOR]