Final Report: Final Report
A decision making tool for farmers considering planting forestry on the less productive and erosion endangered sites on their land, combining written material and computer spreadsheets.
While pastoral farmers are currently enjoying the best returns in a generation, a percentage of most hill country farms is either at risk from soil erosion and accelerated nutrient run-off, or is unsuitable for the further intensification necessary to stay ahead of the game. It is also becoming obvious that environmental concerns will be the next big trade barrier for New Zealand agriculture. With that in mind, the New Zealand Farm Forestry Association has set out to produce a simple easy to use calculator for farmers to employ when deciding what use to put this land to. The calculator will compare different forest species and regimes with current stock production figures from the existing farming operations, and provide the cross-over point where either forestry or farming is more profitable. Three contrasting study farms will be chosen throughout the country, ranging from summer moist North Island volcanic ash soils, through summer dry North Island coastal hill country, to South Island hill country. On the selected farms Land Use Capability Mapping will be used to identify the various land types on the farm, and thus the various threats and opportunities for those land types. On those suitable for forestry different scenarios will be run using the Agroforestry Estate Model, producing a range of options including: grazing without trees, forestry with under-story grazing, forestry without under-story grazing, and wide spaced pole planting.
The first stage of the project in Patoka in western Hawkes Bay is drawing to a close, with the initial findings being written up and presented to a Monitor Farm field day. This has compared farming returns over a five year period from a range of stocking rates, to projected forestry returns from a number of permanent sample plots within a 10km radius of the farm. Forest species used to this point are Pinus Radiata, Poplar and Douglas Fir. It is intended to include Cypress sp. later in the project as more information becomes available. The effect of root biomass on soil stability has also been researched in the project and will be included in the findings.
The written findings and a simple excel based ready - reckoner will be available on the NZFFA website www.nzffa.org.nz in the near future.