November 2000

Commercial timber production is offering North Coast landholders opportunities for income diversification and major long term income. Added attractions are the environmental and nature conservation benefits that can also be enjoyed by integrating farm forestry with existing agricultural enterprises.

Growing trees for timber can be viewed as a form of farm diversification, superannuation investment or as a means of improving capital values. However the perceived longer term nature of income returns from timber and the problem of cash flow can be a deterrent to some farmers taking on farm forestry.

Annuity payments, which are annual instalments based on a projected return from future plantation harvest (similar to those offered by State Forests NSW), can provide one answer. Other solutions within the immediate control of farmers include adopting a whole farm planning approach with a farm forestry focus and utilising farm forestry systems which integrate timber growing with other farm enterprises that can provide some annual income.

Opportunity exists to pasture improve the inter-row area between trees in new eucalypt plantations to provide good quality pastures for grazing cattle on a rotational basis, and importantly some short term income while the trees are growing.

The Department of Land and Water Conservation (DLWC) and State Forests NSW Hardwood Plantations Division continue to monitor joint trial work to determine the best shade tolerant legumes and grasses for growing in eucalypt plantations. This includes evaluating which pasture species persist as the tree canopy forms and the effect of pasture and fertiliser on tree growth rates.

Best pasture species, from results to date, are given in Table 1. All are low growing species.

• The legume Bargoo Joint Vetch is also recommended for drier sites but is currently commercially unavailable. Seed production work has been initiated in partnership with NSW Agriculture, Queensland Department of Primary Industry and a commercial seed producer.

• Indications are that the incorporation at sowing of an annual cover crop with the permanent pasture species assists with weed control, (in addition to providing quick cover and protection against soil erosion). Note that the sowing rate of the cover crop in such pasture mixes must be reduced to one third of the normal cover crop rate to reduce competition with the establishing perennial pasture species. Suitable cover crops are given in Table 2.

• Clovers (such as Haifa Clover at 1kg/ha) can be included in pasture mixes for autumn/winter establishment. Clovers are cheap to purchase, provide quick ground cover, fix nitrogen, which benefits perennial grass species, and improve short term grazing values.

• As an example on drier sites the estimated cost for a pasture mix of Round Leaf Cassia, Bahia Grass, Millet Cover Crop and Fertiliser at the rates recommended in Table 1, is $165/hectare (2000 prices including GST). Made up of $55 seed, $110 fertiliser.

• Cost of application will vary with the technique used eg. the combined cost of separate aerial applications of seed and fertiliser using a fixed wing aircraft or helicopter can vary from $40-$50 per hectare. Cheaper if seed can be mixed with fertiliser and applied in one operation.

• Good cost savings can be achieved by substituting high analysis fertilisers such as Pasture P (17.3P:9.5S 14.3Ca) for Superphosphate (9P:11S).

Site preparation for plantation establishment usually results in some land disturbance as a result of clearing tree regrowth and woody weeds as well as ripping/cultivation operations. Bare ground should be immediately revegetated with cover crops, or cover crops and pasture as a soil erosion control measure.

The opportunity exists to take advantage of this ground disturbance and establish a perennial pasture under the trees using shade tolerant legumes and grasses.

Planting of eucalypt seedlings is best in spring/summer/autumn when moist conditions are prevailing. This is also the optimum time for pasture establishment allowing sowing to proceed when moisture is available. Sowing at tree planting will ensure pasture is well established by the time trees are big enough to allow grazing. (About two (2) metres high, usually around two (2) years of age).

In eucalypt plantations established by State Forests NSW pasture can be established cheaply by using on site contractors. This can be by aerial seeding or by bulldozers mounted with seed boxes. Importantly landholders should have input into seed mixes and sowing techniques to ensure appropriate pasture species are sown and costs are minimised.

For plantations generally it may warrant outlaying more money on seed bed preparation and the right seed mix to ensure a quality shade tolerant pasture is established.

Sowing techniques will be influenced by farm machinery available. The type of machinery used and the degree of seed bed preparation will have an overriding effect on results achieved. Farm tractors, slashers, mulch mowers, boom sprays, ploughs, seed boxes, direct drill machinery, harrows and spinners all have a place.

Ground preparation will be necessary. Ground cover may need to be slashed and/or sprayed with herbicides, and/or ground chisel ploughed to provide a seed bed and soil/seed contact. The better the seed bed preparation and the more accurate the seed placement the better will be the result, climatic conditions allowing. However costs will influence the degree of seed bed preparation.

Aerial seeding is often the most practical sowing option where tree debris and stump holes remain, and is the safest option on steep country.

Techniques include:

• Seed bed preparation with chisel plough, sowing using chisel plough and seed box, fertiliser application and harrowing. Where ground is rough with roots, sticks and stumpholes an offset disc harrow will be preferable to a chisel plough.

• Slashing, spraying off existing ground cover with herbicide, chisel ploughing, harrowing and spinning out of seed and fertiliser.

• Optional slashing, then chisel ploughing (or offset disc harrowing), spinning out seed and fertiliser and harrowing.

• Mulch sowing involving an optional herbicide application followed by spinning out seed and fertiliser followed by mulch mowing or slashing to cover seed.

• Direct drilling involving spraying off existing ground cover with herbicide and direct drilling of pasture seed with appropriate machinery.

• Variations of any of the above as determined by site conditions.

• Aerial seeding using a fixed wing aircraft or helicopter.

• Seed boxes mounted on earthmoving machinery preparing ground for tree planting.

• Residual pre-emergent herbicides and some woody weed herbicides should only be applied to the inter-row areas with caution as they may continue to kill the establishing improved pasture species for some time. With this in mind the label of the herbicide to be used should be checked carefully.

Experience has shown that cattle and sheep grazing without damaging trees is possible when the trees are two metres tall, depending upon stock characteristics and management. Typically the plantation would be two years old at this stage although the age of the trees is less important than their size.

Benefits from the early exclusion of cattle include more efficient pasture establishment and an absence of worm infestations in cattle grazing plantations. Once grazing commences the plantation benefits from the reduced fire hazard and reduced grass competition.

However, the plantation environment is not the same as in grazing paddocks. Plantations are created for the primary purpose of growing trees and owners should be wary of any activities that threaten to damage the trees or to reduce their growth.

Left uncontrolled, stock can cause major damage by trampling young trees, breaking off limbs allowing pathogens to enter the wood, rubbing against young or old trees, compacting the soil and physically damaging tree roots near the soil surface.

Therefore, grazing must be closely monitored in plantations and stock excluded if damage begins to occur.

Practices that can assist in avoiding damage include:

• Leaving gates into plantations open if possible so cattle can move freely in and out and not be encouraged to camp in the plantation. If this is not possible because of property boundaries or mixed farming, the stocking rate should be lowered to avoid damage from stock camps.

• Locating water sources outside of the plantation to discourage cattle from camping in the plantation.

• Monitoring stock activity to ensure that damage does not occur to the trees and roads when the ground becomes wet and soft. Trees are also more easily pushed over in wet soils, particularly when young. Damage to roads (erosion and rutting) and along fence lines can also be caused by stock in wet weather.

• Keeping stock free of ticks, lice, worms etc to reduce the incidence of rubbing against trees.

• Grazing plantations on a rotational basis depending on availability of pasture. Over grazing can lead to increased damage to trees and pasture as stock search for feed. Set stocking should only be at lower stocking rates during peak periods of pasture growth.

• Some considered exclusion of cattle when pasture species are flowering and seeding as many perennial pasture species rely on setting seed to persist eg. on the North Coast one option is winter grazing which will also allow cleared pasture paddocks heavily grazed in the summer to be spelled.

• If possible, control grass around trees to discourage grazing near the trees.

• Be able to respond to conditions in the plantation and be able to move stock if necessary when the first signs of damage occur.

• Assessing stock as described below will also help avoid problems.

So long as the stock are quiet and pest free they will avoid trees if they can see them. Sheep and cattle are acceptable in plantations. However, cattle should be polled or dehorned.

Horses are seldom acceptable in young plantations. They can be very active and can cause extensive physical damage to young trees. Goats should never be allowed in plantations.

Weaners 12 months to 2 years of age are best suited for grazing in young plantations. They should be weaned for at least one month or they may be unsettled and inclined to wander and do damage.

Spayed heifers, steers and cows should not be allowed into plantations until trees are three to four metres tall.

Dry cows and calves and bulls 10 months and over should not be allowed in plantations until the trees have an average diameter breast height (1.3m from the ground) of 10 centimetres.

• Generation of annual income and cash flow from the plantation from year three onwards. Although not substantial this provides a regular income in most years.

• Beef prices affect profitability. Higher beef prices will make for a much more attractive financial proposition.

• Pasture improved plantations potentially have a higher carrying capacity than unimproved plantations because of increased quantity, legume content and quality of pastures. Peak pasture yields are envisaged in years 3 to 6.

* Weaner refers to a 250 kg animal 10-12 months of age.

• Note that although pasture yields should decrease as the tree canopy closes non-commercial and then commercial thinning will open the canopy which should generate additional pasture growth. Non commercial thinning may take place as early as year 5, which should mean better stocking rates than those shown above in later years.

• Will provide extra land available for grazing allowing open cleared pasture land to be spelled for part of the year.

• As many weeds including Parramatta Grass, Crofton Weed and Groundsel Bush do not grow as well in shaded areas and when subject to competition from a vigorous pasture sward, significant savings in annual weed control program costs could flow from pasture improved plantations.

• Pasture by controlling weeds will enhance plantation access for important management operations such as thinning and pruning.

• Green and grazed improved pasture will reduce the fire hazard in plantations. The improved pasture species will also compete with and reduce the more combustible Blady Grass content of the pasture sward.

• In the more protected environment of plantations pasture growth should continue for longer into the colder winter months.

• The improved pasture will provide ground cover and continuing protection against soil erosion.

Alley farming is a farm forestry model where trees are grown in a number of rows with alleys of pasture or crops between them. Imagination is needed to tailor alley farming to the individual farm and the number of tree rows could vary markedly to the six shown below. Where the emphasis is on commercial tree growing at least 11 rows are suggested.

Design variables are alley width, tree belt width, tree density within the belts and orientation of the rows. Rows are preferably orientated north south to retain maximum sunshine for agriculture and to provide wind protection for crops, pasture and livestock. However existing internal fence layout may need to be utilised and along with contour cultivation will influence row orientation.

Alley farming retains flexibility of land use by allowing pasture, crop or fodder production in the "alley" but adds trees as a source of major long term income.

Obviously alley farming caters more for pasture production and grazing, with less chance of the pasture being shaded out as trees grow. Grazing management would be similar to plantations. A perceived drawback is the ‘edge’ effect with trees in the outside rows branching out into the alleys and adversely affecting tree form. However solutions may lie in tree species selection and tree pruning. The production of wood fibre will not be substantially affected by poor tree form, although its value will be less.

This is another farm forestry model where trees are grown in belts of approximately 11 rows, strategically located on the property, preferably by means of a farm plan. Locations may include along property boundaries, main access roads, watercourses, ridgelines, soil or land class boundaries.

For farmers this is often a preferred farm forestry option as it leaves more open country on which to pursue traditional farming and grazing pursuits.

A consideration is the increased length of fencing entailed although property planning will usually see internal fence lines follow the natural features mentioned so that these fences can be used.

For further information contact:

State Forests NSW Hardwood Plantations Division
Phone: (02) 6642 2048 or
The Plantation Officer
for your area