Liberia is located on the west coast of Africa between (4o18’ to 8o30’ north; and 7o 30’ to 11o 30’ west) [Figure 1]. It shares borders with Guinea to the north, Côte d’Ivoire to the northeast and east, Sierra Leone to the northwest and the Atlantic Ocean to the south and southwest. It occupies a land area of approximately 111,370 km2 and has a coastline of about 520 km in length. The population is estimated at approximately 3.8 million (2011), 52 percent of which is rural, with an estimated total of about 230 000 farming families. Monrovia alone accounts for nearly 40 percent of the population, with most of the returning refugees preferring to settle in Monrovia. At a projected growth rate of 2.6 percent per annum, the population is expected to reach 5 million in 2020. According to the Ministry of Agriculture (MoA; 2006), approximately 40 percent of the total population of Liberia is between the ages of 15 and 35 years and a further 40 percent is less than 15 years of age.
The country is made up of four physiographical units: coastal plains (0-100 m amsl), interior hills (100–300 m), interior ridges (300–600m) and the mountainous areas (> 600m). The topography is mainly flat to rolling across the coastal plain and becomes more variable transforming to mainly rolling to hilly and then mountainous with distance from the coast. Broadly, the land can be divided into uplands and lowlands or swamps.
Table 12:Map of Liberia showing Counties and Neighboring Countries
The country in general has two seasons – a wet season from March-April to October and a dry season from November to March, though the beginning and end of either season can vary considerably. Any significant change in the rainfall pattern could adversely impact on production as these crops all yield best under regular and evenly distributed rainfall.
Total average annual rainfall ranges from around 4000mm along the Atlantic coast to approximately 2500 mm at the northern extremes of the country. Average monthly rainfall is lowest in January and highest in September (see Tables 1 and 2).
The strong maritime influence means that the temperatures in the coastal region remain constantly within the relatively narrow band of 18°C to 33°C. Slightly higher maxima and slightly lower minima occur in the dry season, but the range within each band is only about 5°C throughout the year. In the highland region maximum daytime temperatures are slightly higher (35°C) in the dry season, but night time temperatures are considerably cooler (15°C), giving a large diurnal range of some 20°C in December. The wet season daily variations are much smaller, typically only 10°C, and with the daytime and night time temperatures always between 30°C and 18°C respectively.
Wind speeds are generally low (8 to11 m/s) and usually from the west or south, off the sea, though severe winds do occur at times. The records show wind speeds of 21.5 m/s from the east-north-east in April 1962, and another of similar strength from the north-east in April 1963. These were in the force 9, ‘severe gale’ class, which is strong enough to cause minor damage to buildings (AML, 2010).
There are basically four types of soil in Liberia: Latosols (laterites), Regosols (mainly on beach terraces) and Gleysols, covering 75, 21 and 4 percent of the land surface respectively. In addition there are a number of small inclusions of and Fluvisols (recent alluvial soils close to the main rivers). The Latosols are generally the deeply weathered, acid, red (hematite) or yellow (goethite) soils of the humid tropics. These soils have diffuse horizon boundaries, a clay assemblage dominated by low-activity clays (mainly kaolinite) and a high content of sesquioxides. These soils generally have very low organic matter and, due to their acidity, generally have poor fertility. They can, also be very prone to erosion once vegetation is removed and they become disturbed. In particular it can be difficult for vegetation to re-establish on exposed rocky areas, or in soils that have undergone rapid erosion as a result of land clearance for agriculture or other development.
The soils of the middle and upper slopes are often shallow and gravely due to higher incidence of erosion and closer proximity to their parent bedrock, and thus are less suitable for agriculture than those on lower slopes and on terraces close to streams. These latter soils tend to be more variable, generally being browner and courser textures than the upland soils. Throughout the country, there are many small streams that now occupy narrow valley floors that are permanently wet. The latter are the Gleysols which are of variable texture and gravel content and generally are waterlogged.
Table 13:Monthly and annual rainfall totals (mm) for Buchanan
The country has nine major river systems, all of which are perennial, and run in a south-south-westerly direction into the Atlantic Ocean. These rivers have their source in Sierra Leone, Guinea or Côte d’Ivoire. Thus Liberia shares international water resources with her neighbors in the following catchments: St John Basin (Liberia and Guinea), St Paul Basin (Liberia and Guinea), the Cestos Basin (Liberia and Côte d’Ivoire), the Cavalla Basin (Liberia and Côte d’Ivoire), the Moa Basin (Liberia, Sierra Leone and Guinea); and the Mano Basin (Liberia and Sierra Leone). Numerous bilateral treaties have successively governed the delimitation of the frontier of Liberia since 1885 (the Mano River). Some of these treaties have provided for the freedom of navigation and transit fishing and the protection of existing water use rights for the local population.
The first comprehensive land use map of Liberia was prepared in 1956 from aerial photographs taken in 1953. At the time, the map showed extensive forest cover in the northwest and southeast, with some agricultural areas. In 1981, another land use map was prepared from aerial photographs taken in 1979. This revealed the extensive depletion of forest cover, largely due to farming activities.
Approximately 600,000 ha of Liberian land is said to be cultivated, and 220 000 ha of this is reported to be under permanent crop or plantation (rubber, cocoa, coffee and oil-palm), while the rest is arable.
While the plantations tend to provide a solid surface cover that minimizes soil erosion, the arable farming system is largely ‘shifting cultivation’ that exposes a bare land surface, due to the practice of slashing and burning to prepare new fields, to the heavy early raining season rains leading to extensive soil erosion. One survey in northern Nimba (AML, 2010) found that while the fallow period could extend or up to 35 years, the majority of farmers recycled their planting between six and ten years depending, mainly, on the latent fertility of the soils. Thus if the average cycle was (say) 8 years, approximately 50,000 ha of land could be exposed to soil erosion annually
In the 1970s up to the mid-1980s, a number of large, medium and small agricultural development projects were undertaken in Liberia as part of Government efforts to feed the nation and provide certain raw materials for export. These included a number of projects for swamp rice and tree crop development.
Liberia’s forests are said to be home to about 2000 species of flowering plant, 150 species of mammal, 620 species of bird, 125 species of reptile and amphibian and over 1000 described insect species. However, Liberia’s forest habitat and biodiversity face increasing threats from shifting cultivation, mining, logging and the migration of rural settlements. Deforestation is said to occur at a rate of 1.5–2 percent per annum.
Table 14:Monthly and annual rainfall totals (mm) for the Nimba Geologist’s Camp
Source: LAMCO data
Agriculture and forestry is the largest economic sector (64–77 percent – based on contribution to gross domestic product between 1997 and 2005) in Liberia, followed by industry (4–10 percent) and services (19–26 percent). The per-capita GDP was reported as approximately US$130 in 2003. Eight out of every ten people are said to be living on less than a dollar a day. The current Government’s strategy for poverty reduction has been first to stabilize the economy and secondly to increase resource allocation to the social sectors.