Lately, considerable success has been achieved in planting oil palm in organic soils where proper drainage has been implemented. However, palm performance in very deep or young peats can be beset with a host of problems as the palms grow taller, such as tilting palms, flooding during the rainy season, and drought as well as peat fires during dry periods.

The commercially planted D x P = T (Dura x Pisifera = Tenera) hybrid seed material is a heavy feeder and responds well to balanced fertilization. Certain clonal materials are now commercially available in limited supply. Clonal materials are produced from palms selected for their yield, oil-to-bunch ratio, height increment, or other characteristics which are favoured for specific purposes.

The most common spacing is 9 m x 9 m (143 palms / ha), but planting density may range between 128 - 148 palms / ha. Factors affecting the final planting density include the spacing, land terrain, culling of runts in the field, etc. It is an accepted practice by some planters to have an initial high density followed by thinning in the latter years when the shading effect becomes pronounced. A final stand of 136 palms / ha on flat areas and 120 - 125 palms / ha on hilly terrain is considered an optimum density at maturity.

Fertilization is one of the most important aspects in the cultivation of oil palm. With properly balanced fertilization and good management, and where land terrain, soil suitability, drainage and rainfall are not limiting, it is common to achieve yields of between 25 - 30 mt / ha / yr.

In certain instances, even block yields exceeding 40 mt / ha / yr have been attained. Oil extraction rates usually vary from 18 - 23 %, depending on the location, planting material, age of palm, fruit ripeness, etc.

This guide covers fertilizer application at various stages of the oil palm growth, with special consideration being given to types of soil in which the trees are commonly grown in Malaysia.

OIL PALM NURSERY

The success of every palm in the field starts at the nursery stage from seeding to transplanting. Carrying out the correct practices during this stage is of utmost importance, to ensure high yields in the field.

Oil palm seedlings are usually well established about a year prior to field planting. The usual system for such nurseries may vary from a single stage to a two-stage nursery system. The two-stage nursery consists of the pre-nursery and main nursery. The manuring program below is suitable for both systems.

When planting the seeds, it is prudent to plant the smaller seeds separately as these tend to produce smaller seedlings during the early stages, and may be mistaken for runts and thus culled, wrongly. Such seedlings usually catch up with the rest before transplanting.

Planting the seeds in the correct position with the radicle pointing downwards is important. Incorrect positioning of seeds will cause seedlings to become twisted and grow abnormally.

PRE-NURSERY

Young seedlings : from seeding to 16 weeks.

Manuring should start when the first one or two leaves are fully developed and have hardened (about 6 weeks after seeding). A solution containing 40 ml FOLIAR NITROPHOSKA Green 10 - 4 - 7 + TE per 20 litres of water (0.2%) should be applied as a foliar spray at weekly intervals. Alternatively, 150 g NITROPHOSKA Yellow 15 - 15 - 6 - 4 dissolved in 20 litres water may be used for 400 seedlings.

MAIN NURSERY

1. Conventional Method

Older seedlings : from 16 weeks after seeding.

From 16 weeks after seeding, regular manuring with a complete fertilizer should be the practice. The following program is recommended for seedlings from four-months until planting out in the field.

9-month old seedlings under sprinkler irrigation.

In addition, spray 40 ml Foliar Nitrophoska Green 10 - 4 - 7 + TE per 20 litres water (0.2%), at bi-weekly intervals or together with insecticide or fungicide sprays to enhance the vigour of the developing seedlings.

(Nursery Manuring Program)

2. Slow-Release Fertilizer Method

Lately, the use of slow-release fertilizers has gained in popularity with plantation crop growers. The slow-release complex fertilizer TRIABON is especially well suited for use in nurseries as well as during transplanting into the field (Recommended TRIABON Program). It ensures a steady flow of nutrients, makes frequent fertilizer dressings unnecessary and reduces the cost for manual labour.

For both application in the single-stage nursery, Triabon is applied into three small holes dug around the seedling with a plastic pipe (see picture 1.) and then covered with some soil.

Picture 1 - Single Stage

For the two-stage nursery, the first application, at the fourth month after seeding, takes place when transplanting from the small polybag to the big polybag. This is done by first coring out the soil at the centre of the big polybag (see picture 2), then adding the Triabon into the hole, covering with a 2 cm layer of soil, and completing the transplanting in the usual way. For the second application, Triabon is applied into three small holes dug around the seedling with a plastic pipe, and then covered with some soil.

Picture 2 - Two-stage

For both the single and two-stage nursery, the second application of Triabon may be substituted, if needed, by 150 g Nitrophoska Blue Special per seedling applied in the same manner as Triabon.

FIELD PLANTING

The seedlings are normally planted out into the field after 9 - 12 months in the nursery. Whenever possible, it is advisable to use large planting holes of 1.8 m x 1.2 m x 1.0 m deep to enhance establishment, palm growth and subsequent performance. It is standard practice to incorporate 150 - 200 g of Ground Rock Phosphate (GRP) in the planting hole at time of planting.

As a general guide, the following fertilizer programs are drawn up to suit three broad categories of soils in Malaysia :

1. Coastal alluvial soils (e.g. Selangor, Briah, Sitiawan series).
2. Inland soils (e.g. Serdang, Batu Enam, Melaka, Rengam, Jerangau, Tampin, Kuantan, Segamat, Yong Peng series).
3. Peat / Organic soils.

Tables on Field Planting Fertilization Guides :

• for Coastal & Inland soils,
• for Peat / Organic soils.