agricultural land use efficiency and food crop production in ghana

Agricultural land use efficiency and food crop productionin Ghana

Amos K. Quaye • Charles A. S. Hall • Valerie A. Luzadis

Received: 20 March 2009 / Accepted: 22 January 2010 / Published online: 10 February 2010� Springer Science+Business Media B.V. 2010

Abstract Despite the low productivity of the extensive agriculture system, Ghana

recorded the largest reduction of undernourishment in the past two decades. We used

biophysical analysis to determine the efficiency and potentials of the extensive system and

its future sustainability. The results indicate that food production in Ghana has increased

steadily over the past two decades and correlated highly with cropped area and population

(R2 \ 0.85 and 0.82), but not with fertilizer (R2 = 0.06). Sufficient food production could

be sustained in the short term. In the longer term, however, the food situation in Ghana

appears precarious if population growth continues while land remains the same.

Keywords Ghana � Extensive system � Land use efficiency � Starchy staples �Cereals

1 Introduction

The socioeconomic development of Ghana depends heavily on the land and forest

resources used for agricultural growth and rural development. About 50% of the eco-

nomically active population is engaged in agricultural activities, mostly as smallholder

subsistence food crop farmers. Agricultural productivity in Ghana, once very successful,

has become a major source of concern in recent decades, because of the high rates of

population growth and hence the increasing demand for food. Consequently, pressure on

agricultural resources, especially land, has increased (Morgan 1996; World Bank 2006).

Readers should send their comments on this paper to [email protected] within 3 months of publicationof this issue.

A. K. Quaye (&) � V. A. LuzadisDepartment of Forest and Natural Resources Management, SUNY College of Environmental Scienceand Forestry, 1 Forestry Dr, Syracuse, NY 13210, USAe-mail: [email protected]; [email protected]

C. A. S. HallDepartment of Environmental and Forest Biology, SUNY College of Environmental Scienceand Forestry, 1 Forestry Dr, Syracuse, NY 13210, USA

123

Environ Dev Sustain (2010) 12:967–983DOI 10.1007/s10668-010-9234-z

The potential success of the country’s policy of developing agricultural and food self-

sufficiency (Ghana Poverty Reduction Strategy (GPRS) 2003; Medium Term Agricultural

Development Program (MTADP) 1990) is being challenged by a number of biophysical

constraints, most importantly the quality of agricultural lands, the low and erratic rainfall

patterns and the high soil erosion rates (Pearce et al. 1988). Soil erosion has a direct

negative effect on land productivity in crop production, which in turn has serious reper-

cussions for any agrarian economy. Diao and Sarpong (2007) estimated that soil loss

through erosion would reduce agricultural income in Ghana by a total of US$ 4.2 billion

and cause a 5.4% point increase in the poverty rate over the period 2006–2015. This is

approximately five percent of total agricultural GDP in this 10-year period.Food crop production in Ghana has been mainly through the extensive system of

shifting cultivation. This is the oldest farming system (Nye and Greenland 1960) in which

farmers ‘‘slash and burn’’ a piece of land, grow food crops in polyculture for 1–3 years and

leave it fallow. It is socially and environmentally sustainable (Thrupp et al. 1997), albeit at

low levels of agricultural productivity and human population densities (Boserup 1965).

The fallow phase restores carbon and nutrient stocks in the biomass, improves soil physical

properties and suppresses weeds (Nye and Greenland 1960; Szott and Palm 1986). Thus,

productivity depends on the intrinsic soil quality and the length of fallow period. However,

due to increasing population pressure, the fallow period has been progressively shortened

resulting in lower crop yields (Seini 2002). The length of the fallow period varies for

different parts of country. In less populated regions, fallow range can exceed 5–10 years.

Fallow periods are often only 2–3 years in parts of the Coastal Savanna and the Forest

zones or 4–6 years in parts of the Guinea and Sudan Savanna zones (Quansah et al. 1991,

2001; Food and Agriculture Organization (FAO) 1991). These short periods are considered

insufficient to sustain soil productivity under intense cropping (Acquaye 1990; MOFA

1998).

The most common response to the extensive system in the face of the increasing

population numbers is agricultural intensification through the use of chemical fertilizers,

other agro-chemicals and technological means to increase crop yields. The potential of this

type of fossil fuel-driven intensification, however, is also limited for most developing

countries because of the expense. When human population pressures exceed a critical

density, the traditional shifting cultivation is replaced by a variety of other agricultural

practices (Sanchez et al. 2005). In Ghana, Asuming-Brempomg et al. (2003) identified five

such practices that replace the shifting cultivation: rotational bush fallow, permanent tree

crops, compound farming, mixed farming, and special horticultural farming systems. The

rotational bush fallow system is currently the dominant farming system throughout Ghana.

It is designed to include the planting of specific crops such as legumes and other nitrogen-

fixing trees in the rotation. However at the rotation of the fallow, bush clearing and land

preparation methods are the same as those for traditional shifting cultivation. Thus makes

the soil susceptible to erosion leading to soil infertility (Asuming-Brempomg et al. 2003).

Agricultural land use efficiency (LUE), also known as productivity or yield, is deter-

mined as tons of crop produced divided by the total number of hectares of land devoted to

the production of that crop in any particular year (tons/ha/year). Fertilizer use efficiency

(FUE) is determined as tons of crop produced divided by the tons of fertilizer used in the

production of that crop in a year (ton/ton) (Hall 2000). Agricultural land is defined as the

sum of arable crops (land under food crop production, mostly temporary), permanent crops

(land used for the cultivation of perennial tree crops), and permanent pasture (land used for

herbaceous forage). Most research papers on agricultural productivity use this definition in

their analysis, which does not include fallow lands. When fallow lands are not considered

968 A. K. Quaye et al.

123

in such analyses, the results can be deceptive by portraying that land as not limiting.

However, when in non-industrialized agricultural farming systems, fallow is essential. In

this paper, agricultural land is redefined to include fallow lands.

In spite of the low land use efficiency or productivity nature of soils under these

extensive systems of farming, and the progressive reduction in the fallow period that

sustains it, FAO data indicate that Ghana recorded a large reduction (52%) of under-

nourishment1 in the past two decades (Food and Agriculture Organization (FAO) 2000;

Meyers 2001). The purpose of this study is to determine, from a biophysical perspective,

how long it may be feasible for Ghana to adequately feed its people under the traditional

farming system. We looked at efficiency of agricultural land use, its contribution to

improvement in food crop production in the past, and its future sustainability. To meet

these objectives we tested the hypothesis that the traditional systems of food crop pro-

duction and hence increased cropped land has not and will not pose a threat to the limit of

food production in the near future (in the next decades), at the present rate of population

growth in Ghana. We used historical empirical data to analyze the production trends of the

major food crops produced in Ghana from 1962 to 2004 and the biophysical factors

responsible for their increased production. We also made projections into the future (2031)

using a biophysical model to determine the state of future food production and availability.

The rest of the paper gives a brief description of the location of the country, the nature

and characteristic of the agriculture and its importance to the national economy and rural

society (Sect. 2), outlines the sources and empirical analysis of the data and describes the

details of the model used for the estimation of food and land availability including for-

mulas and factors (Sect. 3), presents the results of data analysis and model projections and

then discusses possible factors that influenced the result (Sect. 4) and offers suggestions for

plausible solution (Sect. 5).

2 Characteristics and importance of agriculture in Ghana

Ghana is located on the southern coast of West Africa, between latitudes 4�440 N and

11�110 N and longitudes 3�110 W and 1�110 E. The country is divided into six agro-

ecological zones based on climate: High Rain Forest, Deciduous Forest, Transitional Zone,

Coastal Savanna, Guinea Savanna and Sudan Savanna. The natural vegetation in each

agro-zone is determined by the different climatic conditions and soil type. Mean annual

temperature in the country ranges between 26 and 29�C in August–September and 31–

33�C in February–March. Mean annual rainfall ranges from 800 mm in the Coastal

Savannah to 2,200 mm in the Rain Forest. The rainfall pattern is uni-modal in the Sudan

and Guinea Savannah Zones and bi-modal in all the other zones (Ministry of Food and

Agriculture (MoFA) 2003).

Ghana has a total land area of 238,533 km2 of which agricultural land covers about

57%. Agricultural production is made up of traditional exportable cash crops (cocoa, oil

palm, cotton, rubber, and coconut), non-traditional export or horticultural crops (e.g.

pineapples, mango, citrus, chili pepper, tomatoes, other fruits and vegetables) and the

staple food or subsistence crops, which can be grouped into cereals (maize, rice, sorghum,

and millet), starchy staples (cassava, yam, plantain, cocoyam, and sweet potatoes), and

legumes and pulses (cowpea, groundnut, and beans). The rearing of livestock on free range

1 Under-nourishment is defined as that food intake level that is insufficient to meet dietary energyrequirements continuously.

Agricultural land use efficiency 969

123

is common throughout the country; however, the main concentrations are in the drier and

grassland areas to the north of the country (Aryeetey and Fosu 2003; Ministry of Food and

Agriculture (MoFA) 2001).

Agriculture in Ghana is generally rain-fed and almost exclusively represented by

smallholder activity farming on plots of less than 1.5 ha. Productivity is generally low

mainly due to the use of low-input traditional farming systems and the erratic nature of

rainfall in the country. Where opportunities for improved water management and irrigation

exist, agriculture in Ghana possesses many natural advantages. As such, the application of

existing technologies to smallholder systems would increase unit area yields for crops

significantly (Ministry of Food and Agriculture (MoFA) 2005). The soils of Ghana are

highly weathered with predominantly light textured surface horizons in which sandy loams

and loams are the common textural classes. Thus, most lands are characterized by poor

fertility and are subject to degradation due to erosion (Diao and Sarpong 2007). To sustain

increases in crop production and therefore ensure food security, soil nutrient and water

resources must be managed properly and conserved (Quansah 1996).

Despite the challenges to successful agricultural production, it is still the dominant

sector in the Ghanaian economy. Agriculture employs about 60% of the labor force, mainly

as small landholders, contributes about 40% to GDP and accounts for over 57% of foreign

exchange earnings (Ministry of Food and Agriculture (MoFA) 2003). The agricultural

sector is the major source of government revenue, mainly through duties paid on exports of

agricultural commodities, particularly cocoa. The contribution of agriculture to govern-

ment revenue was 26% in 1987, but it declined to an average of about 20% in the first half

of the 1990s (Seini 2002). By 2004, however, real GDP grew at 5.8%, the agriculture

sector led with a growth rate of 7.5% and contributed 46.7% of overall growth (Institute of

Statistical, Social and Economic Research (ISSER) 2005; Aryeetey and Fosu 2003).

Agriculture also plays important roles in the socioeconomic development of Ghana. It

contributes to ensuring food security, provides raw materials for local industries, and

provides incomes for much of the population, thereby contributing to poverty reduction.

3 Materials and methods

We used empirical data on total national and agricultural population numbers and their

growth rates, total national agricultural land area, area cultivated in each of the major food

crops, and total food production and yield/ha. Other data included total national fertilizer

use and climatic variables. These data cover the period from 1962 to 2004.

Food crops included in this study are the cereals (maize, rice, sorghum, and millet) and

the starchy staples (cassava, yam, and plantain). We analyzed the time trends of production

for each of these crops individually, in the two broad groups and for the overall total of all

food crops. We corrected all production figures for moisture content of each crop in order

to obtain production figures on dry weight basis. We analyzed the efficiency of land and

fertilizer use from the above-mentioned data and also determined the relations of yields to

these biophysical factors. We used simple correlation analysis to determine which of the

biophysical factors were most important factor driving food production in Ghana.

The principal sources of data for this study were the Food and Agriculture Organization

(FAO) of the United Nations, Ghana’s Ministry of Food and Agriculture (MoFA), and the

Ghana Meteorological Services. Additional data from the scientific literature that were

used are referenced accordingly.


123

3.1 Empirical analysis of land and fertilizer use efficiency

To analyze the performance of the traditional system of food production, we determined

the efficiency of land and fertilizer used for food production. Explicit crop-specific fer-

tilizer use values are not available for Ghana, so we calculated the amount of fertilizer

applied to each crop by modifying a formula initially developed by Hall et al. (1998).

Fertðc;yÞ ¼ FertFacðcÞ � NaFertðyÞ =Areaðc;yÞ ð1Þ

where Fert(c,y) is crop-specific fertilizer use for a particular year, FertFac(c) is a weighting

factor of total fertilizer consumption that is applied to a crop (Table 1), NaFert(y) is the

total National fertilizer use for all crops in a particular year, and Area(c,y) is the area

harvested for a particular crop in a particular year. We derived land use intensity by

dividing the total agricultural land by the total population to determine per capita land

availability, which is also a measure of population pressure on agricultural land.

3.2 The Simulation model

We developed a computer simulation model,2 we called SimGhana, using FOR-

TRAN90v4. SimGhana is based on similar models developed by Hall (2000). The model

simulated the food production as a function of area cultivated, the amount of fertilizer

used, and a land quality factor. We first derived a saturating fertilizer limiting factor using

the equation:

FLFac ¼ TFpHa=TFpHa þ HafSat ð2Þ

where FLFac is fertilizer limiting factor, TFpHa is the amount of fertilizer used per hectare

of crop produced and HafSat is a half-saturation coefficient.3

To determine the half-saturation coefficients of fertilizer use by each crop, we made

assumptions based on literature and expert knowledge (Food and Agriculture Organization

Table 1 Factors and values used in the simulation model (SimGhana) to simulate food production as afunction of area cultivated, the amount of fertilizer used, and a land quality factor

Foodcrop

Area(1,000 ha)

Yield(100 kg ha-1)

Half-saturationcoefficient

Scope of responseto fertilizer

Erosionfactor

% moisturecontent

Maize 610.40 15.26 0.06 0.65 5.0 0.15

Rice 94.90 15.90 0.07 0.76 0.0 0.15

Millet 208.50 5.39 0.08 0.50 5.0 0.15

Sorghum 262.60 9.19 0.08 0.54 5.0 0.15

Cassava 534.70 115.79 0.05 0.39 5.0 0.62

Yam 227.30 106.63 – – 7.0 0.70

Plantain 173.50 67.91 0.05 0.35 3.0 0.65

Cocoyam 202.90 63.91 – – 7.0 0.63

Sources FAO, MoFA, IFDC Hall (2000) and Parajuli (2003)

2 A predictive or simulation model attempts to represent quantitatively relatively well-known systemallowing simulation of the future or hypothetical states (Hall and Day 1977).3 The quantity of fertilizer that generates half the maximum amount of crop production that is determined asthe asymptote where any further addition of fertilizer input will have little effect on productivity.


123

(FAO) 2005, 2002; Hall 2000; Parajuli 2003; [Table 1]). Since fertilizer use in Ghana is

very low and has not reached the asymptotic response of crops, we assumed the base year

yield to be one of no fertilizer use. Therefore, predicted crop yields were calculated as:

YpHa Pr ¼ NFYpH þ SfRes * FLFac * EroFacð Þ ð3Þ

where YpHaPr is the predicted yield per ha with fertilizer, NFYpH is crop yield per ha

without fertilizer, SfRes4 is the scope of crop response to fertilizer use, and EroFac is an

erosion factor. Based on the predicted yields, simulated total productions for each crop for

the country were calculated as:

CPro ¼ YpHpr * Area *LQFacð Þ ð4Þ

where crop production (Cpro) is the product of area (Area) cultivated, the predicted yield

(YpHPr, corrected for erosion effects), and land quality factor (LQFac). The use of a land

quality factor is based on the assumption that farmers use the best land first (Ricardo 1817).

According to Hall (2000), agricultural land quality can be represented by a numerical

factor where 1 = best land, 0.5 = medium quality, and 0 = worst. Considering the nature

of soils in Ghana (Food and Agriculture Organization FAO 2002) and the reduction in the

fallow period (Seini, 2002; Quansah et al. 1991, 2001, we assumed a land quality factor of

0.7 and fallow period of 5 years for this model. Sensitivity analysis on these values and

assumptions was carried out as part of this study and gave us confidence that the results of

our model were correct and sensitive to unforeseen changes in these factors.

4 Results and discussion

Results from the empirical analysis indicate that food production in Ghana has increased

steadily over the past two decades (Fig. 4). Thus, the traditional system of food production

through the expansion in cropped area has sustained food production, without appreciable

industrial inputs. Because fertilizer use in Ghana is very low (Fig. 5), the observed

increases in food production could not be explained by fertilizer use. It is evident, there-

fore, that the increases in food production have come about primarily through expansion of

cropped area. The simulation results also show that enough food could be produced to meet

the dietary requirements of the people of the country for the next 2 decades (Fig. 10). In the

longer term, the potential of the extensive system for food self-sufficiency may be limited

by availability of quality land due to the progressive reduction in the fallow period.

However, this problem apparently can be avoided if sustainable land management systems

are practiced. Therefore, we accept the hypothesis that the traditional system of agricultural

production, and hence expansion in cropped area, has not been a limiting factor to food

crop production in Ghana for the past and the short-term future (i.e. next two decades).

4.1 Land use efficiency and food crop production

Active agricultural land expanded by 26%, from 11.70 million ha in 1962 to 14.74 million

ha in 2003 (Fig. 1). When fallow land was included, total agricultural land increased to 21

million ha in 2004. Increases in the area cropped for each food crop is presented in Fig. 2.

Agricultural land use efficiency (LUE), i.e. yield, is an index of the performance of an

4 This is the maximum amount of increased yield that can be added to the no-fertilizer base year yields. It isthe difference between maximum yield with fertilizer and the yield without fertilizer, in tons per ha.


123

agricultural system which in Ghana is fairly low. Rice and cassava are the highest yielding

crops among the cereals and starchy staples, respectively (Fig. 3).

The increases in yield observed in Fig. 3 are similar to those reported by Aggrey-Fynn

et al. (2003) and Seini (2002) which they attributed to the development and introduction of

improved high-yielding crop varieties in the late 1980s and early 1990s by the Ghana Crop

Research Institute (CRI). Total food production increased sharply by 76% from 4.1 million

Mt in 1991 to 7.2 million Mt in 2004 (Fig. 4). Food crop production in Ghana is signif-

icantly correlated with the area harvested (p = 0.03 and p = 0.02 for cereals and starchy

staples, respectively).

Maize cultivation occupies about 27% of land devoted to all food crops and about 52%

of land devoted to cereals, whereas rice cultivation occupies 4.1% of food crops land and

7.7% of cereals land. Rice production grew irregularly at around 5% per year from 1970 to

1990. The most widely cultivated and consumed starchy staple in the country is cassava,

whose production occupies about 22.6% of all land devoted to food crops and about 48%

of land devoted to starchy crops. According to Institute of Statistical, Social and Economic

Research (ISSER) (2005), cassava is currently becoming the largest agricultural product in

0

6

12

18

24

1962 1972 1982 1992 2002A

rea

(mill

ion

Ha)

Fallow Land

Other Land Use

Permanent Pasture

Food CropsPermanent Crops

Fig. 1 Agricultural land use inGhana between 1962 and 2003.Source FAOSTAT Home Page(2004)

0.0

0.4

0.8

1.2

1.6

1962 1968 1974 1980 1986 1992 1998 2004

Are

a (M

illio

n ha

)

0

0.4

0.8

1.2

1.6

1962 1968 1974 1980 1986 1992 1998 2004

Are

a (m

illio

n ha

)

Cassava

Maize

Sorghum

Millet

Rice

Plantain

Yam

A

B

Fig. 2 Total area harvested(Million Ha) for cereals (a) andstarchy staples (b) in Ghanabetween 1962 and 2004. SourceFAOSTAT Home Page (2004),MoFA


123

Ghana. It represented about 22% of agricultural GPD in 2004. Cassava is grown exten-

sively in almost all the agro-ecological zones of Ghana. The Food and Agriculture

Organization FAO (2002) identified two reasons for the widespread cultivation of cassava

0.0

0.5

1.0

1.5

2.0

1962 1972 1982 1992 2002Y

ield

(M

t ha-

1)

Mean MaizeRice MilletSorghum

0.0

1.0

2.0

3.0

4.0

1962 1972 1982 1992 2002

Yie

ld (

Mt h

a-1)

Mean Cassava

Yam Plantain

A

B

Fig. 3 Mean yield of cereals (a)and starchy staples (b) in Ghanabetween 1962 and 2004. SourceFAOSTAT Home Page (2004),MoFA

0.0

0.5

1.0

1.5

2.0

2.5

1962 1968 1974 1980 1986 1992 1998 2004

1962 1968 1974 1980 1986 1992 1998 2004

Pro

duct

ion

( M

illio

n M

t)

0.0

1.0

2.0

3.0

4.0

5.0

Pro

duct

ion

(Mill

ion

Mt)

Cassava

Cassava

Plantain

Yam

Millet

Rice

Sorghum

A

B

Fig. 4 Total production of foodcrops: cereals (a) and starchystaples (b) in Ghana between1962 and 2004. SourcesFAOSTAT Home Page (2004),MoFA


123

in the country; the first being the drought in 1983, following which many farmers turned to

cassava because it tolerates drought and grows in relatively poor soils. Secondly, it can be

harvested anytime between 8 and 24 months after planting, thus providing a safeguard

against unexpected food shortages.

4.2 Fertilizer use efficiency and food crop production

The amount and efficiency of fertilizer use is an index of the extent of modern agricultural

intensification through industrial inputs. Fertilizer use is very small in Ghana (Fig. 5) and,

as such, the extent of modern agricultural intensification is very low. The low inputs of

fertilizer did not show any substantial increase to yields. In fact the correlation between

crops yield and fertilizer use is not significant, R2 = 0.06 and 0.02 for cereal and starchy

staples, respectively. Nevertheless, efficiency of fertilizer use, expressed as ton of crop

production per ton of fertilizer used, decreased with increasing fertilizer use (Fig. 5).

From a biophysical perspective, one common interpretation of the observed non-

responsiveness of crops to fertilizer is that the quality of agricultural soils in Ghana is high.

According to Hall (2000), applying fertilizer to high-quality soils does not lead to any

significant increase in yield because when plants have readily access to sufficient intrinsic

nutrients in the soil, they do not respond to applied fertilizers. This is highly unlikely for

Ghana, given the character of the soils that have poor fertility and high susceptibility to

erosion (Diao and Sarpong 2007). Although the shifting cultivation system helps to restore

soil fertility, the progressive reduction in the fallow period makes it extremely unlikely for

Ghanaian soils to regain higher fertility levels (Morgan 1996). According to FAO (2005),

almost all the crop nutrient balances in Ghana show nutrient deficiencies. According to the

estimates, cassava and yam account for about 37% of the nitrogen deficit. These crops

remove large quantities of nutrients, and their soils are prone to erosion during harvest.

Gerner et al. (1995) also reported that agricultural practices under the extensive system

0

2

4

6

8

1962 1972 1982 1992 2002

Fer

t use

(10

0 m

t)

0

2

4

6

8

10

12

14

16E

ffici

ency

(10

00 T

/T)

EfficiencyFert use

0

2

4

6

8

10

12

1962 1972 1982 1992 2002

Fer

t use

(10

0 M

t)

0

5

10

15

Effi

cien

cy (

1000

T/T

)Fert Use Efficiency

A

B

Fig. 5 Fertilizer use andefficiency by cereal-maze (a) andstarchy staples-cassava (b) inGhana between 1962 and 2003.Sources FAO, MoFA and IFDC


123

especially with a declining fallow period are soil exhausting. They indicated that crop

production in Ghana is far below its potential and if fertilizers were used the country has

the potential to produce two to three times of its current production levels. Seini (2002)

attributed the drastic reduction in fertilizer use in the country since the 1980s (Fig. 5) to the

introduction of the Structural Adjustment Program (SAP) and the removal of agricultural

supports, including fertilizer subsidies by the Government of Ghana.

4.3 Climatic variables and food crop production

Precipitation and mean ambient temperature (MAT) are the most significant climatic factors

in tropical agriculture. Since agriculture in Ghana is predominantly rain-fed, reduction in

the quantity of rainfall affects crop production significantly. Between 1961 and 1990,

precipitation decreased by about 20% in the country (Fig. 6). However, we found the

correlation between the yields of crops and mean annual rainfall to be not significant with

R2 \ 0.2. This relation is probably due to the erratic pattern and the variability in distri-

bution of the rainfall amount in the country. The significant decline in food production

observed in 1983 and 1990 was due to severe drought in those years and consequent

reduction in area cropped (see Figs. 2, 4). However, above average rainfall in the years that

followed them (1984 and 1991) resulted in a sharp increase in production (see Fig. 4).

4.4 Population growth, land availability, and food production

The relation between population growth and food production has been a contentious issue

of study both historically (e.g. Malthus 1798; Boserup 1965) and in recent years (e.g. Hall

2000; Benneh 1990; Benneh 1993). The number of people engaged in agriculture can be

used as a measure of the extent of agricultural extensification or intensification. The

agriculture population in Ghana has been increasing, but at a decreasing rate relative to the

total population (Fig. 7a). Thus, the percentage of the economically active population in

agriculture is declining; however, it is still above 50%. Food production correlates highly

(R2 = 0.82) with population, indicating that labor is a major factor in food production

second only to land. Although the increasing population provides labor to the agricultural

sector, it has also resulted in a decline in per capita agricultural land (Fig. 7b). Conse-

quently, there has been a reduction in fallow period. In apparent agreement with Boserup’s

(1965) view, as the population growth occurred, use of available land increased enough to

increase food production, even though yields per hectare are relatively low.

Our simulation results predicted that Ghana’s population would increase to 23 million in

2010, 26.34 million in 2020, and 30.5 million in 2031 (Fig. 8). Figure 9 indicates that food

production could be increased to feed about 84% of the simulated population from 2010 to

2031.

0

2

4

6

8

10

12

1962 1972 1982 1992 2002

Mea

n an

nual

rai

nfal

l (1

000m

m)

25

25

26

26

27

27

28

28

Mea

n A

nnua

l tem

p (°

C)

MAR

MAT

Fig. 6 Variations in meanannual temperature (MAT) andmean annual rainfall (MAR) inGhana between 1962 and 2003.Source Ghana MeteorologicalServices (unpublished data,several years)


123

Given the expected high prices of fertilizers and the weak relation between crop pro-

duction and fertilizer, which is most likely due to insufficient fertilizer application, the

predicted increase in food production could be achieved only through increased expansion

of cropped area. Based on the 5-year fallow period, our model projected that the total

agricultural land required to sustain the predicted increase in food production will surpass

the total land area of the country by 2023 (Figs. 10, 11). Since this is impossible, it is likely

that farmers will reduce the fallow period even further, which will adversely affect the

fertility of agricultural land and ultimately food production.

4.5 Low yields, poverty, and farmer migration

The low yields associated with crop production in Ghana could be attributed to poverty

among farmers, which prevents them from practicing healthy farm management.

0

4

8

12

16

1962 1967 1972 1977 1982 1987 1992 1997 2002A

gri

c.P

op

(mill

iom

)

52

54

56

58

60

62

64

% A

gri

c. p

op

ula

tion

Agric Pop

%Agric Pop

Fig. 7 Total and percentage ofagricultural (Agric) population(Pop) in Ghana between 1962and 2004

0

1

2

3

4

1961 1966 1971 1976 1981 1986 1991 1996 2001Land

per

cap

ita (

ha/p

erso

n)

per capita total landper capita agric landAgric land/agric pop

Fig. 8 Land availability percapita in Ghana between 1962and 2002. Source FAO, GoG

0

10

20

30

40

1991 2001 2011 2021 2031

Pop

ulat

ion

(mill

ion)

FAO estimate

Simulated

Fig. 9 SimGhana simulated andFAO estimated populationgrowth of Ghana (1991–2031)


123

According to Ghana Poverty Reduction Strategy (GPRS) (2003) and Ghana Statistical

Service (GSS) (2004), poverty is highest (59%) among food crop farmers. Seini (2002)

noted that a majority of Ghanaian farmers were unable to afford or adopt improved

agricultural technologies, particularly the use of chemical fertilizers, tractors, or irrigation

facilities due to poverty.

The declining percentage of farmers of the total population could also be attributed to

rural–urban (internal) migration. Most farmers, especially the youth, are leaving the rural

farming communities for the cities in search of white-collar jobs with the aim of getting

better income to improve their livelihood and that of their relatives (Benneh et al. 1996).

Their aims are mostly met but only relative to their formerly impoverished life in their

former communities. A second possible cause of the decline is the increased level of

education. Education has become a high priority in most rural communities as an attempt

to depopulate agricultural lands (Benneh et al. 1996). Educated individuals seek

employment in economic sectors other than agriculture, set up their own businesses in the

cities, or travel out of the country. A third cause could be attributed to the aggregation of

farmlands. In general, land is communally owned in Ghana, and individual family or

community members have usufructuary rights (Nukunya 1972; Ollenu 1962; Asenso-

Okyere et al. 1993). Commercialization of land in Ghana has recently become an issue.

Some community chiefs have started outright sale or long-term lease of community lands

to rich individuals who often come from outside the community or foreign countries. These

individuals usually practice large-scale intensive agriculture and grow mainly exportable

crops such as pineapple, pawpaw, and exotic vegetables. This practice has caused many

traditional farmers to lose their farm lands, become landless, and flee their communities to

find work elsewhere. Sometimes though, they become employed to work on these com-

mercial farms.

0

100

200

300

400

500

600

700

800

1991 2001 2011 2021 2031F

ood

supp

ly (

kg/c

apita

)

0

5

10

15

20

25

30

Fee

ding

pop

ulat

ion

(mill

ion)

Food supplyFeeding Pop

Fig. 10 Simulated food supply(kg capita -1) and population thatcan be fed in Ghana (1991–2031)

0

5

10

15

20

25

1991 2001 2011 2021 2031

Are

a (m

illio

n H

a)

Other land use

Simulated food crop land

Simulated fallow land

Permanent Crops

Permanent pasture land

Fig. 11 Simulated agriculturalland use in Ghana (1991–2031)


123

Boserup (1981) hypothesized that population growth is a principal driver of agricultural

innovation in peasantry. This perspective suggests that when land area is reduced relative

to population, farmers can compensate by modernizing agricultural techniques. But the

development of agriculture in Ghana is limited by the socioeconomic situation of farmers

such as the system of communal land ownership and by their relative poverty. Almost all

food crop farmers still use the traditional farming system of shifting cultivation and have

not been able to adopt any modern agricultural technologies (Okai 1997). Most food crop

farmers are not using the high-yielding crop varieties released by the Crop Research

Institute, because they are used to the old varieties or because they have not been exposed

to the new varieties due to lack of agricultural extension and education.

Most farmers in Ghana are aware of the importance of agro-inputs and the value of

modern farm practices, but they cannot afford the cost of those practices. If the credit

market favored farmers, most of them would most likely adopt modern farming practices

and make better use of research findings (Seini and Nyanteng 2003). The results of this

study essentially show that population growth in Ghana has had little effect on agriculture

modernization or the adoption of new techniques as postulated by Boserup.

The extensive system of agriculture, which makes use of land expansion to feed

growing populations, also causes rapid reduction in forest cover. Loss of forests affects

human livelihood directly by depleting timber and non-timber forest resources. It also

results in land degradation through soil erosion (Pimentel 1987), which in turn affects the

biodiversity of agro-ecosystems by disturbing the natural process of soil fertility restora-

tion. Soil loss has a direct negative effect on land productivity in crop production, which in

turn has repercussions for the rest of the economy (Biggelaar et al. 2004). Considering the

increasing recognition of the importance of agriculture in reducing poverty of small-scale

farmers and improving the overall socioeconomic development of the country, the

development of alternative agricultural systems that reduce poverty, meet farmers’ needs,

and minimize the impact on environmental resources must be promoted (McNeely and

Sherr 2003).

Sustainable land management has been identified as a key to reducing agricultural soil

loss and overcoming the negative effects of erosion on agricultural production, income

growth, and poverty reduction (Diao and Sarpong 2007). In Ghana, such alternative land

management practices include rotational bush fallow, compound farming, mixed farming,

and intercropping and agroforestry systems. These systems are characterized by initial

slash and burn which destroy the vegetative cover and makes the soil susceptible to erosion

(Asuming-Brempomg et al. 2003). Crops planted after slash and burn benefit from the

nutrients in the ash, but rapid nutrient depletion takes place with successive nutrients

removal in crop harvest, nutrient leaching, runoff and erosion promoted by high rainfall

and rapid decomposition of soil organic matter after burning (Sanchez 1976). It will

therefore be necessary to incorporate leguminous trees and crops in the intercropping and

agroforestry systems.

In addition, fallows may be improved or managed by planting trees. The leguminous

trees or crops planted in these systems would fix nitrogen and thus restore soil fertility

more rapidly (Boddey et al. 1996). In the mixed farming system, and where livestock

farming is practiced, the manure from animals could also be incorporated into the soil to

improve the organic matter content of the soil. Agricultural residues, including the inedible

biomass of harvested crops also need to remain on the farm land and be incorporated in the

soil (Acquaye 1990; Ahenkora and Appiah 1996; Quansah et al. 2001; Erenstein 1999).

Such systems of organic agriculture through alternative land management and land

intensification systems have been estimated by Badgley et al. (2007) to be capable of


123

producing enough food on a global per capita basis to sustain the current population and

potentially an even larger population without increasing the agricultural land area. Diao

and Sarpong (2007) have also estimated that the impacts of these sustainable land man-

agement practices on mitigating the effects of soil loss would lead to a US $1.4 billion

increase in real agricultural GDP in Ghana by 2015.

The challenge, however, has been the barriers to adoption of these systems by small-

holders. According to Sanchez et al. (2005), farmers will invest in improved land man-

agement and care for the environment if it is profitable compared with other investment

options within the context of household constraints and individual time preferences and

attitudes toward risk. The promotion of these systems must therefore consider the profit-

ability, labor needs, food security, and equity issues associated with them.

5 Conclusion

Increased food production in Ghana has come about mainly through increased cropped

area and labor. The future potential of the traditional system of food production appears to

be limited because expansion in area cropped to food crops cannot continue forever.

Further reduction in the fallow period will likely result in the limitation of land area and

increase soil exhaustion. Based on the current 5-year fallow period of agricultural land in

the country, agricultural land would have to surpass the total land area of the country by

2023 in order to maintain the current levels of food crop production. This is of course

impossible both physically and because of other necessary land uses. Agricultural growth

through acreage expansion is therefore not sustainable for the long-term future of the

country considering the fact that population growth and consequently, increased food

demand will continue but the land area will remain the same with decreasing quality and

productivity.

More sustainable agricultural practices available to improve the Ghana’s future food

security include mixed farming, intercropping, agroforestry systems, and managed fallows

that involve the use of legumes for nitrogen fixation and the incorporation of animal and

crop residue into the soil for improvement in soil organic matter content. These alternative

land intensification systems, if promoted with considerations to the profitability, labor

needs, food security, and farmers’ need, would increase food production to meet the

demands of the growing population without increasing the agricultural land area.

To conclude, Ghana is faced with three possible solutions to ensure future food security:

(1). intensification of agricultural production through the use of industrial inputs; (2).

encouragement of more stringent family planning to reduce the pressure of population

growth; and (3) development of agricultural and poverty reduction policies that support

sustainable agriculture practices. The first solution is very difficult in a future of con-

strained global oil availability. The second solution, if done with sensitivity and without

coercion but rather through increasing education and options for young women, is much

more desirable than the first alternative. Population reduction taken together with the third

solution, sustainable land management practices, will likely produce the most desirable

outcomes.

Acknowledgments We are very thankful to the Ford Foundation International Fellowships Program,under the Institute of International Education (IIE), and the State University of New York, College ofEnvironmental Science and Forestry (SUNY-ESF), Syracuse for supporting Amos’ Master’s degree programwhich led to the production of this work.


123

References

Acquaye, D. K. (1990). Towards development of sustainable agriculture in Africa: Reflections of a soilscientist. In M. A. Zobisch (Ed.), Proceedings of the 11th annual general meeting of soil sciencesociety of Ghana.

Aggrey-Fynn, E., Banini, A., Croppenstedt, A., Owusu-Agyapong, Y., & Oduru, G. (2003). Explainingsuccess in reducing under-nourishment numbers in Ghana. ESA working paper no. 03-10.

Ahenkora, Y., & Appiah, M. R. (1996). Promoting food security through soil fertility management. In F.Ofori & E. Y. Safo (Eds.), Proceedings of the national workshop on soil fertility management actionplan for Ghana (pp. 61–75). Accra Ghana: Ministry of Food and Agriculture.

Aryeetey, E., & Fosu, A. (2003). Economic growth in Ghana: 1960–2000, Mimeo. Nairobi: African Eco-nomic Research Consortium.

Asenso-Okyere, W., Atsu, S. Y., & Obeng, I. S. (1993). Communal property resources in Ghana: Policiesand prospects. Institute of Statistical, Social and Economic Research, University of Ghana, Legon.Discussion paper no. 27.

Asuming-Brempomg, S., Botchie, G., & Seini, W. (2003). Socio-economic analysis and the role of agri-culture in developing countries. Country case study Ghana. FAO roles of agriculture project, ISSER,University of Ghana, Legon-Accra.

Badgley, C., Moghtader, J., Quintero, E., Zakem, E., Chappell, M. J., Avile0s-Va0zquez, K., et al. (2007).Organic agriculture and the global food supply. Renewable Agriculture and Food Systems, 22(2), 86–108.

Benneh, G. (1990). Population growth and development in Ghana (PIP/Ghana booklet) revised.Benneh, G. (1993). Population, environment and sustainable development in Africa. Paper presented at the

general conference and 25th anniversary celebration of the AAU, University of Ghana, Legon, Accra,Ghana, January 13–18.

Benneh, G., Morgan, W. B., & Uitto, J. I. (1996). Sustaining the future: Economic, social, and environ-mental change in Sub-Saharan Africa. Tokyo: United Nations University Press.

Biggelaar, C., Lal, R., Wiebe, K. and Breneman, V. (2004). The global impact of soil Erosion on pro-ductivity. In Advances in agronomy (Vol. 18).

Boddey, R. M., de Morraes Sa, J. C., Alves, B. J. R., & Urquiaga, S. (1996). The contribution of biologicalnitrogen fixation for sustainable agricultural systems in the tropics. Soil Biology and Biochemistry,29(5–6), 787–799.

Boserup, E. (1965). The conditions of agricultural growth. The economics of Agrarian change underpopulation pressure. London: George Allen and Unwin Limited.

Boserup, E. (1981). Population and technology. Oxford: Basil Blackwell.Diao, X., & Sarpong, D. B. (2007). Cost implications of agricultural land degradation in Ghana; An

economy wide multimarket model assessment. IFPRI discussion paper no. 00698.Erenstein, O. C. A. (1999). The economics of soil conversation in developing countries: The case of crop

residue mulching. Thesis, Wageningen University.FAOSTAT Home Page. (2004) apps.fao.org/.Food and Agriculture Organization (FAO). (1991). Ghana land resources management study. Report no:

103/91 CP-GHA.28, Rome.Food and Agriculture Organization (FAO). (2000). The state of food insecurity in the world 2000, Rome.Food and Agriculture Organization (FAO). (2005). Fertilizer use by crop in Ghana. Rome Food and

Agriculture Organization (FAO), FAOSTAT Home Page (2004) apps.fao.org/.Food and Agriculture Organization FAO. (2002). The state of food insecurity in the world 2002. Rome.Gerner, H., Asante, G. H., Owusu-Bennoa, E. O., & Marfo, K. (1995). Ghana privatization scheme. Lome:

IFDC-Africa.Ghana Poverty Reduction Strategy (GPRS), 2003–2005. (2003). An agenda for growth and prosperity,

Volume I: Analysis and policy statement.Ghana Statistical Service (GSS). (2004). Ghana living standard survey report, 1989/1999, Accra Ghana

Meteorological Services Department (several years) Accra, Ghana Government of Ghana [GOG] andthe World Bank 2000, In An action plan for developing agricultural input markets in Ghana IFDC,2001 Report.

Hall, C. A. S. (2000). Quantifying sustainable development: The Future of tropical economics. London:Academic Press.

Hall, C. A. S., & Day, J. W. (1977). Ecosystem modeling in theory and practice. An introduction with casehistories. New York: Wiley Interscience.

Hall, C. A. S., Ko, J., Lee, C., & Wang, H. (1998). Ricardo lives: The inverse relation of resourceexploitation intensity and efficiency in costa rican agriculture and its relation to sustainable


123

http://apps.fao.org/

http://apps.fao.org/

development. In S. Ulgaldi (Ed.), Advances in energy studies: Energy flows in ecology and economy(pp. 355–370) . Rome: Musis.

Institute of Statistical, Social and Economic Research (ISSER). (2005). The state of Ghanaian economy in2004, Accra.

Malthus, T. R. (1798). An essay on population. New York, Augustus Kelley, Bookseller, reprint in 1965.McNeely, J. A., & Sherr, S. J. (2003). Ecological agriculture: Strategies to feed the world and save

biodiversity. Washington: Island press.Medium Term Agricultural Development Program (MTADP). (1990). Ministry of agriculture. Government

of Ghana.Meyers, W. H. (2001). Success and failure in achieving the goals of the world food summit. In Sustainable

food security for all by 2020. IFPRI, 2001. September 4–6, 2001. Bonn, Germany.Ministry of Food and Agriculture (MoFA). (1998). National soil fertility management action plan (p. 159).

Accra: Ministry of Food and Agriculture (MOFA).Ministry of Food and Agriculture (MoFA). (2001). In IFDC, 2001. An action plan for developing agri-

cultural input markets in Ghana; Report.Ministry of Food and Agriculture (MoFA). (2003). Agriculture in Ghana: facts and figures. Produced by the

Statistics, Research and Information Directorate. Accra.Ministry of Food and Agriculture (MoFA). (2005). Agriculture in Ghana: facts and figures. Produced by the

Statistics, Research and Information Directorate. Accra.Morgan, W. B. (1996). Economy and society: Development issues. In G. W. Benneh, B. Morgan, & J. I.

Uitto (Eds.), Sustaining the future: Economic, social, and environmental change in Sub-SaharanAfrica. New York: United Nations University Press.

Nukunya, G. K. (1972). Land tenure and inheritance in Anloga. ISSER Technical publication series no. 30.University of Ghana, Legon.

Nye, P. H., & Greenland, D. J. (1960). The soil under shifting cultivation. Technical communications 51.Commonw. Bureau of soils, Harpenden, UK.

Okai, M. (1997). Agricultural production, food security and poverty in West Africa. In W. K. Asenso-Okyere, G. Benneh, & W. Tims (Eds.), Sustainable food security In Africa. Dordrecht: KluwerAcademic Publishers.

Ollenu, N. A. (1962). Principles of customary land laws in Ghana. London: Sweet and Maxwell.Parajuli, R. R. (2003). An analysis of the relationship between human population growth and cereal supply

in Nepal. MS thesis, Department of Environmental Science and Forest Biology, State University ofNew York, College of Environmental Science and Forestry, Syracuse, NY.

Pearce, D. W., Barbier, E. B., & Markandya, A. (1988). Environmental economics and decision-making inSub-Saharan Africa. London: International Institute for Environment and Development/UniversityCollege London Environmental Economics Center.

Pimentel, D. (1987). Soil erosion effects on farm economics. In J. M. Harlin & G. M. Berardi (Eds.),Agricultural soil loss processes, policies and prospects (pp. 217–241). Boulder: Westview SpecialStudies in Agriculture, Science and Study.

Quansah, C. (1996). Soil, water and nutrient management needs for sustainable crop production. In Pro-ceedings of DSE international seminar on tools for analysis and evaluation for sustainable land use inrural development, DSE, Zscortan, Germany.

Quansah, C., Bonsu, M., Mahama, S., Batsa, H. P., & Gana, B. K. (1991). Preparatory work, land and waterresources management study. Accra, Ghana: Ghana Environmental Resources Management Project,MOFA.

Quansah, C., Drechsel, P., Yirenkyi, B. B., & Asante-Mensah, S. (2001). Farmers’ perceptions and man-agement of soil organic matter—A case study from West Africa. Nutrient Cycling in Agroecosystems,61(1–2), 205–213. Kluwer Academic Publishers.

Ricardo, D. (1817). The principles of political economy and taxation. G. Bell and Sons: London.Sanchez, P. A. (1976). Properties and management of soils in the tropic. New York: Wiley.Sanchez, P. A., Palm, C. A., Vosti, S. A., Tomich, T. P., & Kasyoki, J. (2005). Alternatives to slash and

burn: Challenge and approaches of an international consortium. In C. A. Palm, S. A. Vosti, P. A.Sanchez, & P. J. Erickson (Eds.), Slash and burn agriculture: The search for alternatives. New York:Columbia University Press.

Seini, W. A. (2002). Agricultural growth and competitiveness under policy reforms in Ghana. Institute ofStatistical, Social and Economic Research (ISSER), University of Ghana Legon, Technical publicationno. 61.

Seini, W. A., & Nyanteng, V. K. (2003). Afrint macro study: Ghana report (revised). Legon-Accra: Instituteof Statistical, Social and Economic Research (ISSER). University of Ghana.


123

Szott, L. T., & Palm, C. A. (1986). Soil and vegetation dynamics in shifting cultivation fallows. In Firstsymposium on the Humid tropics (Vol. 1, pp. 360–379). Embrapa, Belem, Pera, Brazil.

Thrupp, A., Hecht, S., & Browder, J. (1997). The diversity and dynamics of shifting cultivation: Myths,realities, and policy implications. Washington, DC: World Resources Institute.

World Bank. (2006). Ghana country environmental analysis. The World Bank and the ENRM Sector Group.NRM Consultative Group (CG) Meeting, May 19.


123

agricultural land use efficiency and food crop production in ghana

Documents