Agroforestry

Growing timber with traditional farm product to benefit farmers, the timber industry and the environment

Agroforestry on Jim & Mary Frith's farm
a short drive from Bridgetown

Enhanced Production

The total production of an agroforest paddock is greater than production from stock or trees alone.

A paddock planted with widely spaced trees can support nearly the same number of sheep or cattle as when treeless. In a sheltered environment stock use less energy. Tree shelter also improves survival rates of newborn lambs and calves.

In an agroforest, trees can grow twice as fast as in plantations. Agroforest trees are less crowded and there is less competition for water, sunlight and soil nutrients. Clover planted for grazing animals provides extra soil nitrogen which boosts tree growth.

Farm Incomes

Agroforestry could provide a sound source of farm income in high rainfall areas. Commercial timber is now grown and harvested on about a ten year cycle. It could be a profitable cash crop insulating farmers from fluctuating markets by the diversity of products offered by agroforestry.

Most existing agroforest farms are using proven commercial trees such as pines (Pinus radiata) and blue gums (Eucalyptus globulus). However other species suitable for furniture and fine crafts may also be considered by farmers interested in longer term investment.

Exciting future

Agroforestry has the potential to resolve many problems for farmers, foresters and the environment.

Land Care

Clearing land for farming has caused massive salt problems and eutrofication of coastal inlets. A welcome side effect of agroforestry is that it largely solves these problems. Planting of farms to agroforest lowers the water table, preventing salinisation. Similarly agroforest uses surplus fertiliser from farmland and prevents phosphates reaching and spoiling coastal waterways.

Saving Native Forests

Agroforest farmers growing commercial sawlogs and pulpwood can play an important part in easing pressure on our unique native forests.

Farms are a logical place to grow short rotation timber crops which can form a sound basis for a truly sustainable timber industry.

Where will agroforestry work?

Areas with annual rainfalls higher than 500mm can support agroforest for timber production. Many farmers in lower rainfall areas are conducting trials to find tree species most suitable to their farms.

10 hectares of agroforest will produce the equivalent of 7 hectares of pasture plus 8 hectares of plantation.

The trees are more widely spaced than in most plantations. Cropping and grazing occurs between them. Trees may be randomly dotted over the whole area, or arranged in narrow strips alternating with broader strips of agriculture (alley farming).

Minimum tree shade on the pastures is achieved by planting in a north-south direction. Other factors such as land contours and prevailing winds will also direct the farmer's choice of orientation.

For further information

This article is designed as a brief guide. For more technical information on agroforestry please contact;

Jim Frith, Agroforester, Bridgetown Phone/Fax: ( 08) 9761 1176

Sources:

ANDERSON G, MOORE R and JENKINS P The interaction of pasture, livestock and widely spaced pine in south west Western Australia. Agroforestry systems 6: pp 195 - 211 {1988)

BARI M and SCHOFIELD N Effects of agroforestry-pasture associations on groundwater level and salinity. Agroforestry systems 16: pp 13 31

FRITH JL Land degradation, agroforestry and paper pulp mills in Western Australia. Paper presented to the bienniaql conference of the Australian Forest Growere, Launceston, Tasmania, 1994.

MATTINSON B, MORRISON D, and ECKERSLEY P Economics of tree farming in the south west of Western Australia. Proc seminar "Trees everybody profits" AIAS, Perth W.A. 1989

SHEA S and HEWETF P Plantation forestry in Western'Australia. Achievements and prospects. Dept of CALM Perth W.A. 1990