Soil Conservation Service officers offer advice on weed control

Prepare the site for planting by removing rocks and stumps and levelling sharp gullies and mounds. This will enable the harvester to operate smoothly with a minimum of damage to the collection system and the coffee trees.

The NSW Soil Conservation Service is currently a division of NSW Primary Industries. Soil Conservation Service officers can provide on-site advice and surveying skills to locate roads, head drains, diversion banks and tree rows to minimise erosion and make the most efficient use of available land. Advice is also available on appropriate ground covers to stabilise slopes, minimise weed competition and protect soil between rows.

September is the best time to prepare the site because storm rain is unlikely and spring rainfall (Northern New South Wales) or irrigation (North Queensland) will allow the grass cover or cover crops to establish before heavy summer storms. After the site is cleared of surface rock and scrub vegetation, mark planting rows with pegs.

Note: Deep ripping along the rows to break hardpans and improve root penetration is recommended at all sites, but is essential if planting in shallow soils in North Queensland.

Mounding:

Northern NSW coffee plantation

Much of the land is too steep for the traditional run off controls of contour or diversion banks. The runoff control system which is easiest to build and works most efficiently is to run mounded tree rows and associated drains downhill. Experience has shown that kikuyu swards can be successfully excavated and quickly revegetated with minimal short term soil loss. The benefit of long term protection from erosion more than outweighs the costs. Low-growing legumes or other cover crops can also be planted immediately after excavation.

In North Queensland;

Mounding has not been used however contour mounding offers advantages on side slopes up to 5%. Excavating broad, shallow drains in the inter-row area creates low profile, mounded tree rows. The shallow drains do not affect machinery operations.

Building mounded rows:

If you are establishing a new plantation and want to build mounded rows, rip discontinuous planting lines (i.e. a two metre gap every 15 to 20 metres) when preparing the site. The gaps will help prevent erosion along the rip line. Then excavate cultivated soil in the centre of the inter-row area to a depth of 15 cm and put this soil in the proposed tree row, making a mound 30 cm above the low point in the middle of the inter-row.

Pre-plant fertilisers:

It is a good idea to incorporate any required lime or dolomite and phosphorus in the mounded strip. Have the soil tested to establish pH, calcium, magnesium and available phosphorus levels. Coffee prefers a pH of (CaCl2) or 5.5-6.0 (water). Most soils will not require heavy lime or dolomite application.

Phosphorus is important for root growth and is not very mobile in the soil. It is difficult for surface applications to reach the root zone, so it is a good idea to incorporate phosphorus before planting. A rate of 150 to 200 grams of single superphosphate per metre of tree row can be banded in behind a single ripper tyne before planting.

Windbreaks:

Coffee plants and windbreak

Coffee thrives in a sheltered tropical forest environment and trees are adversely affected by strong or drying winds. Strong winds can ‘lodge’ trees, causing root damage and profuse sucker growth. Young trees are especially susceptible and can be ringbarked where the stem of the tree rubs against the soil. Lodged trees are difficult to machine-harvest.Exposed sites require windbreaks, particularly on boundaries and ridges, and within the plantation on persistently windy sites. Where wind protection is provided, the benefits in tree health, vigour and yield will be noticed. Consult your local forestry officer for suitable species, planting distances and required distances between the windbreak species and the coffee.

Monterey pine (Pinus caribaea), river red gum (Eucalyptus camalduensis), Casuarina spp. and tallow wood (Eucalyptus microcorys) have been used successfully as boundary windbreaks in different locations. Previous experience has shown that windbreak seedlings require irrigation for the first two to three years to ensure they reach an effective height quickly. Windbreaks are most effective when planted as double rows.

Internal windbreaks are usually necessary for the first two to three years until the coffee trees form hedgerows, after which the hedgerow itself becomes a good windbreak. Coffee seedlings are particularly sensitive to wind during the first year of growth. Even a temporary row of sorghum or maize for spring/summer planting or lupins for autumn planting can shelter young seedlings when planted about 100 cm from the tree row. After the windbreak has served its purpose it can be cut and used as mulch around young trees. Semi-permanent or permanent internal windbreaks may be required every five to ten rows depending on the degree of wind exposure. Commonly used internal windbreak species include bana grass (Pennisetum purpureum x p, americanum), lemon-scented tea tree (Leptospermurn petersonii), and Hakea salicifolia in Northern New South Wales.

Bana grass is the most commonly used species in North Queensland. Allow four metres from the bana grass to the coffee trees and rip yearly between the grass and the coffee trees to prevent root competition. It is also recommended to top the bana grass to prevent seeding and thicken the windbreak.

Shade:

The Australian experience supports overseas findings that highest yields are obtained from unshaded, irrigated and fertilised coffee (Willson, 1985). Shade is not recommended for commercial coffee production.