Trees are planted on farms to address a variety of issues including the need to improve environmental values and enhance financial return. The most successful planting's are achieved when a thorough on-farm planning process is undertaken prior to putting trees in the ground. The result of such a planning process should be a whole farm plan, which includes the objectives, design criteria and constraints for the woodlot. In this way a carefully planned woodlot or plantation can satisfy a range of identified on farm needs.

Commercial timber species incorporated into a farming system and aimed at meeting both economic and environmental objectives can enable short term benefits such as stock shade and shelter to be achieved, while providing income diversification through timber harvesting in the long term.

A variety of plantations types based on variations in species are available to maximise benefits. Broad species types used in plantations include exotic pine, native pine, hardwood/eucalypt, rainforest cabinet timbers and paulownia.

Woodlots, tree belts and alley farming offer options to standard plantation design. Further information on plantations, species selection, and various tree-growing layouts is available in the Department of Land & Water Conservation publication "Planning for Farm Forestry – A Practical Guide". Specific information on species selection and establishment can be obtained from various other sources including Queensland Department of Natural Resources Tree Facts.

Matching tree species to site conditions is a key component in the establishment of a successful plantation or woodlot. Establishment is usually viewed from the perspective of choosing a particular site and then determining the most appropriate tree species for those site conditions. An alternative approach is to select a tree species to grow and then survey the area for site conditions that will suit that particular tree species.

Species selection can be difficult and should include research as to what species are going to suit particular on farm needs as well as what timber products will be in market demand at harvest time years in the future. A good place to start is to investigate plantation species that are doing well in the local area. Forestry consultants can assist in developing a plantation.

Characteristics that should be considered when determining "site quality" and associated potential for growing particular timber species are listed below. Note that moisture and soil type are the main limiting factors for many tree species:

Rainfall (moisture), frost and wind are crucial environmental parameters, which can effect seedling growth. A good understanding of seasonal variations in rainfall is also required prior to determining planting time frames.

Depths to rock and soil erodibility are key constraints to tree development, as is the soils ability to retain moisture and nutrients. For these reasons sites with a reasonable depth of soil and good drainage are ideal, however species can be chosen that will grow on a range of soil types.

Topography

It essential to consider slope when planning a plantation especially with regard to site preparation and maintenance, access roads and tracks as well as harvesting methods. Generally steeper slopes make future operations such as weed control, pruning, thinning and harvesting as well as the establishment of stable plantation access difficult and more costly (however plantations can still be grown on steep slopes). Aspect and altitude are also key features particularly with regard to prevailing winds, fire hazard, moisture availability and retention.

Domesticated stock will need to be excluded from the plantation, at least during the initial stages, therefore the more difficult or longer the area is to fence the higher the initial cost of plantation establishment.

Wallaby browsing can be a problem to seedlings particularly when the plantation adjoins native forest. Options include individual tree guards to a reasonable height (generally at least 1 metre high), kangaroo fencing around the plantation or the use of dogs.

Wildfire can devastate plantations so it is essential to have a well-maintained network of fire trials and tracks.

It is essential the landholders be aware of the various pieces of legislation that can affect the establishment of a plantation including:

• Timber Plantations (Harvest Guarantee) Act, 1995 administered by the Department of Urban Affairs and Planning. Will be repealed when the P&R Act is invoked.
• Plantation and Reafforestation Act, 1999 (P&R Act) administered by the Department of Land and Water Conservation. Will replace the Timber Plantations (Harvest Guarantee) Act and will come into force when a Code of Practice is finalised and gazetted.
• Native Vegetation Conservation Act, 1997 (NVC Act) administered by the Department of Land and Water Conservation.
• Threatened Species Conservation Act, 1995 (TSC Act) administered by the National Parks and Wildlife Service. This Act is assessed by DLWC when doing consent assessments under the NVC Act and P&R Act.
• The Environmental Planning & Assessment Act 1979 (EP&A Act) does not apply to plantation operations on an authorised plantation or exempt farm forestry (as specified in the P&R Act). However operations that are ancillary or not primarily for the plantation operations are still subject to the EP&A Act.

Information on how each Act affects a specific plantations operations can be obtained from the government body that administers the Act.

Once each of the above factors have been considered it is time to develop a Plantation Plan. Such plans are best recorded on an aerial photograph enlargement of the whole property or at least the section of interest and have a scale of between 1:2,000 to 1:5,000. Using the air photo as a back drop, the Plan, with the aid of clear plastic overlays should record different physical, environmental and construction attributes and constraints. Features recorded on the plan should include:

The plan should detail existing roads and any new roads required including culverts and major creek crossings. In addition the boundary of the area to be developed should be recorded as well as new and existing fence lines.

Physical features

Overlays should detail soil type, contour lines (to give an idea of slope), drainage features including creeks and rivers as well as the type of all existing vegetation. In addition direction of prevailing winds and the direction of the main fire danger should be recorded.

Initial weed control strategy, location of different species to be planted, as well as location and orientation of fire breaks should all be detailed.

Ongoing weed control, maintenance of fire breaks, and silvicultural practises should be detailed including the timing of different operations.

Any plan should detail the method and sequence with which the trees will be harvested and should take into consideration limiting factors affecting the site, especially access.

From this plan a budget detailing establishment and approximate maintenance costs can be worked out and a time-line of operations can be produced.

Once a whole farm plan has been completed and the establishment of a plantation is considered to be a worthwhile proposition then an establishment regime can be developed. The guiding principle for establishment is "the growth of a tree throughout its whole life is established by the first two years of growth"(Greening Australia – Dorrigo). It is therefore important to get the young trees off to a good start to ensure that their full productive potential can be realised.

Seedlings should be ordered well in advance. This will give the nursery the time to grow them. It is worthwhile inspecting your seedlings regularly during the growing period. Two features, which significantly reduce seedling vigour, are J-rooting and root binding. When inspecting for these problems roots, remove the seedling from the pot and look for a root system that is growing downwards with white fibres visible.

Seedling costs vary markedly depending on size, species and number purchased, indicative costs are as follows:

• Hiko trays of eucalypts planted at 1000 stems/hectare $150-$180/hectare
• Individual eucalypt seedlings can cost up to $0.50 each
• Rainforest/cabinet species around $1.00 each

Ground preparation is essential to ensure adequate moisture and root penetration into the soil profile. Typically this is achieved by at least ripping rows and may also include ploughing or mounding on the contour. Ripping is usually undertaken using a bulldozer with a single tyne attached with a winged ripper boot. The winged ripper boot allows for additional soil shattering and results in better moisture penetration. Ripping depth should be between 70-85cm.

Bulldozer with single winged ripper tyne

An off-set disc plough

Whilst not essential mounding enables a deeper topsoil bed to be developed and will assist with drainage and weed control. Ploughing mechanically kills weeds and provides a better seed bed for planting operations. Commercial rates for rip plough or rip mound are generally between $125-$150/hectare.

Row spacing is typically between 3 and 4 metres with stems planted at between 2.5 to 4 metre centres. A four-metre row spacing allows tractor access for maintenance slashing and weed control activities. However a closer spacing may be preferred to give a greater selection of stems from which to choose during thinning operations.

Weeds competing with seedlings for light, moisture and nutrients are a major limiting factor in tree development and the most common cause of poor growth rates. Therefore seedlings should be planted into a weed free environment and this may require up to two pre-planting applications of herbicide. The first a broad-spectrum glyphosate based chemical, blanket or strip sprayed along the rows followed by the application of a pre emergent residual herbicide. A standard cost for the initial herbicide application prior to cultivation is around $150/ hectare with the follow-up application at or after cultivation costing around $110/ha. Any subsequent herbicide application required will cost around $100/ha.

When applying herbicides, label instructions should be followed and the climatic conditions chosen carefully. Residual herbicides are particularly likely to cause problems if used before heavy rains as they have potential to be transferred off site by stormwater runoff.

An alternative to this involves ploughing or mounding tree rows to bury or mechanically destroy weeds prior to planting, or combining ploughing or mounding with herbicide application.

Once planted, the seedlings will require a one-metre diameter circle around them to be kept weed free, this can be achieved by either chemical or mechanical methods. Greening Australia have also found that mulching around each tree can also be a successful weed suppressant. Post planting chemical control may require up to two applications of a suitable herbicide. Indicative costs for herbicide are around $100/hectare per application including herbicide.

In any plantation seedlings should be planted when they will grow well. This means planting in an appropriate season and only when soil moisture is high.

Through various trials Greening Australia have found the following standard guidelines should be followed regardless of the method of planting:

• Soak seedlings before planting.
• Plant seedlings firmly so that there are no air pockets around the root ball and the roots are making good contact with the soil.
• Bury the root plug to a depth of 20-40mm below the surface. This will prevent the root plug from drying out in the first few days after planting.
• Plant the seedling upright.

Generally eucalypt plantations should be established in early spring or planted during late summer, pine in the period May to July and rainforest cabinet timbers February to May. An indicative planting cost for seedlings is around $150/hectare.

Planting implements can include items like special purpose planting spades or a Pottiputke or tube like instrument specifically designed for planting tree seedlings from Hiko type seed trays. When seed beds are well prepared experienced operators can plant approximately 2000 seedlings a day.

A Pottiputki tree planting tool

Fertilising

Research has shown that the application of a nitrogen/phosphorus compound fertiliser around the time of planting can optimise the establishment and early growth of both eucalypt and pines.

Fertilisers are available in various forms, including bagged, prilled fertiliser or tablets. Tablets may have some benefit in providing a slower release of nutrient. Generally they are more expensive but are easier to apply.

Greening Australia's experience through the establishment of demonstration sites at Dorrigo has shown that seedlings should be fertilised 4 weeks after planting once the roots have started to grow. It has also been found that when fertilising it is best to place 50 grams of fertiliser 75mm below the surface or 150 grams on the top of the ground approximately 200 mm away from the seedling. Nitrogen is lost to the air when fertiliser's are placed on the ground so it is best to do this when raining. Fertilising seedlings will cost around $85/hectare ($25 for materials and $85 for application)

Plantation Maintenance

Follow up maintenance is critical to ensure the plantation gets a good start. This includes weed control, a second application of fertiliser and tree replants in any failed sections. Greening Australia's experience would indicate that a successful plantation should achieve an 80 % survival rate and that the seedlings are one third higher than any broad leaf weeds on site. A good quality site should achieve 2 - 4 metre tall trees at the end of the second season. Postplant refilling of dead seedlings will cost around $70/hectare.

Cole-Clark, B. 1999. "Planning For Farm Forestry-A Practical Guide" (NSW Department of Land and Water Conservation).

Farming for the Future. Property management planning workshop series 1997 (NSW Agriculture, Department of Land and Water Conservation and National Parks and Wildlife Service).

"Establishing Farm Forestry Plantations – Planning a Farm Forestry Operation that Suits You" (Greening Australia. Dorrigo Farm Forestry Project).

Northern NSW Farm Forestry Information Catalogue. (Department of Land and Water Conservation and Northern Rivers Regional Development Board).