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Difficulty: HardAgricultural Systems, Crop Production, and Pastoralism in Nigeria

In Nigeria, commercial oil palm (*Elaeis guineensis*) plantation agriculture is heavily concentrated across the humid southern forest belt in states such as Imo, Ondo, and Akwa Ibom, but cannot be commercially sustained in northern states like Kano or Katsina even with soil fertilization. Which set of environmental constraints primarily explains why commercial oil palm cultivation is unsuccessful in northern Nigeria?

  1. A prolonged dry season of 5 to 7 months, low atmospheric humidity, and mean annual rainfall below 1,000 mmAnswer
  2. B
    Excessive annual sunshine hours combined with loose, well-drained sandy soils of the Sudan Savanna
  3. C
    High incidence of trypanosomiasis vectors and seasonal waterlogging in low-lying river valleys
  4. D
    High soil acidity levels and low mean annual temperatures during the rainy season

Answer

A prolonged dry season of 5 to 7 months, low atmospheric humidity, and mean annual rainfall below 1,000 mm
The spatial distribution of tree cash crops in Nigeria is governed primarily by the latitudinal rainfall gradient. Oil palm requires a humid climate with high, well-distributed rainfall exceeding 1,500 mm annually and elevated atmospheric humidity throughout the year. Northern Nigeria suffers from a short rainy season and an extended dry period of 5 to 7 months aggravated by dry Harmattan winds, which severely limits oil palm development and commercial viability.

Step-by-Step Solution

1
Analyze the ecological requirements of oil palm (*Elaeis guineensis*) in Nigeria.
Oil palm is a tropical evergreen tree crop requiring heavy, year-round rainfall (1,500–3,000 mm) and high relative humidity without long dry spells.
Tree cash crops in Nigeria are strictly zoned according to latitudinal rainfall and moisture availability gradients.
2
Evaluate the climatic conditions of northern Nigeria (Sudan/Sahel Savanna).
Northern Nigeria experiences a short rainy season (3–5 months) and an extended dry season (7–9 months) marked by dry Harmattan winds and low mean annual rainfall (<1,000 mm).
The moisture deficit during the long dry season induces severe moisture stress, flower abortion, and low oil yields in oil palms.
3
Identify the primary limiting factor for northern cultivation.
Moisture deficit, low humidity, and rainfall insufficiency represent the main ecological barriers.
Soil nutrients can be amended artificially, but macro-climatic moisture limits cannot be economically offset across large-scale non-irrigated plantations.

Key Concept

Ecological Zonation of Agricultural Cash Crops in Nigeria
Estimated Time:1m 30s
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Topics

Agricultural Systems, Crop Production, and Pastoralism in Nigeria

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