3 A farmer in a tropical region grows oil palm as a cash crop on a 15-hectare plantation. (a) State two climatic conditions that are suitable for growing oi...

(a) Two climatic conditions suitable for growing oil palm [2]

Oil palm is a tropical perennial that thrives in hot, wet equatorial climates. Any two of the following are accepted:

1. High rainfall, typically 1500-3000 mm per year, distributed fairly evenly across the months so the palms receive continuous moisture. [1]
2. High temperature in the range 25-30 °C year-round, because oil palm is frost-sensitive and photosynthesis in the canopy peaks at these temperatures. [1]
3. High humidity, which reduces water stress on the broad fronds.
4. Abundant sunshine to drive photosynthesis and oil accumulation in the fruit.
5. Evenly distributed rainfall throughout the year (no prolonged dry season).

(b) Why seedlings are raised in a nursery before transplanting [2]

A nursery stage allows the farmer to:

1. Select only the most vigorous and uniform seedlings for field planting, discarding weak or off-type plants. This ensures a productive, even stand in the plantation. [1]
2. Provide protection from pests, diseases, and harsh weather during the vulnerable early months, while controlling watering and nutrient supply more precisely than would be possible in an open field. [1]

Transplanting strong, healthy seedlings reduces the replanting rate and gives the plantation a head start.

(c) Two products from oil palm fruits [2]

Any two of:

1. Palm oil - extracted from the fleshy mesocarp of the fruit. It is used in cooking, soap making, and many processed foods. [1]
2. Palm kernel oil - extracted from the hard kernel inside the fruit. It has different fatty-acid properties and is used in cosmetics and confectionery. [1]
3. Palm kernel cake - the residue after oil is pressed from the kernel, used as a protein-rich animal feed.
4. Palm wine - tapped from the sap of the tree (less common as a fruit product).

(d) Why fruit bunches must be processed within 24 hours [2]

Once a fresh fruit bunch is harvested, enzymes in the bruised fruit begin hydrolysing the oil. Free fatty acid (FFA) levels rise rapidly, which:

1. Causes the oil quality to deteriorate - high FFA makes the oil rancid, darker, and harder to refine. [1]
2. Leads to economic loss, because oil with high acidity fetches a lower price and may be rejected by processing mills. Quick processing preserves the maximum yield of high-quality, low-acidity oil. [1]

(e) One disadvantage of oil palm monoculture [1]

Any one of:

• Soil nutrient depletion, because the same nutrients are removed year after year without the diversity of crops to cycle different elements.
• Build-up of pests and diseases specific to oil palm, since the continuous host population allows pest populations to multiply unchecked.
• Loss of soil structure over time.
• Reduced biodiversity in the plantation ecosystem.

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(f) One reason for planting cover crops between rows of young oil palms [1]

Any one of:

• To prevent soil erosion by protecting the bare ground from direct rainfall impact.
• To suppress weed growth that would compete with the young palms.
• To add organic matter to the soil as the cover crop decomposes.
• To fix atmospheric nitrogen if a leguminous cover crop (e.g. Pueraria) is used, enriching the soil for the palms.

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