Programme provides data to inform decision making about planting native shrubs on hill country
Many farmers with steep erosion prone hill country are interested in revegetation with native species. Planting native plants can offer increased native biodiversity and provide erosion control.
Farmers also want to know if native shrubs can be used as an alternative forage for livestock in hill country.
Trials were established in the Manawatu and Mahia to assess the establishment, growth and forage value of native shrubs
Pilot studies evaluated several different aspects of native shrubs including establishment, growth and forage value; metabolisable energy content and digestibility analysis of the foliage; feed preference in sheep; economics of planting natives based on modelling and mātauranga applications of native species.
Native species that were studied included: Hoheria populnea (Houhere), Pittosporum crassifolium (Karo), Griselinia littoralis (Pāpāuma), Coprosma robusta (Karamū), Coprosma repens (Taupata), Melicytus ramiflorus (Māhoe), Pseudopanax arboreus (Whauwhaupaku) and a shrub willow.
Farmers wanting to plant natives on steep hill country are faced with a number of opportunities and challenges
Some key findings from this research included:
- Establishment rates of native shrubs can be very high (>90%) in favourable environments but where conditions are not favourable survival over the first summer can be low.
- For hill country farmers wanting to browse native shrubs once established, foliage and fine stems appear to be palatable to livestock (sheep). Their metabolizable energy content is reasonably good (range 10-12 MJ kg-1 DM) but protein content of both leaves and small stems is low.
- Modelling of whole farm production and profitability using discounted cashflow analysis indicated that the economic viability of planting native shrubs is mostly dependent on the value of carbon credits.
Keen to know more?
Acknowledgements
A big thank you to James Millner (Massey University) for taking the lead on this project for New Zealand’s sheep and beef farming community.