Rice production and development in Ghana

J.W. Oteng
Senior Research Scientist, Faculty of Agriculture, University of Ghana, Legon, Accra, Ghana

INTRODUCTION

Ghana experienced a rapid dietary shift to rice, particularly in the urban centres, during the early post-independence period (starting 1957). The trend was attributed to increased income, favourable government pricing policies, good storability of rice and ease of cooking (Nyanteng, 1987).

Imports and consumption

Rice consumption in Ghana increased from 7.4 kg per caput/annum between 1982 and 1985 (WARDA, 1986) to 13.3 kg per caput/annum (Government of Ghana, 1996) resulting in a total annual consumption of 239 400 tonnes of milled rice (i.e. estimated on 18 million population). The annual consumption (1991-1996) thus showed an increase of 119 000 tonnes over that of 1990. The total paddy production was 329 080 tonnes, an estimate based on an average yield of 1.9 tonnes/ha over a total area of 173 200 ha (Table 1).

Production generated a milling output of 204 030 tonnes (i.e. 62 percent), leaving a demand gap of 29 000 tonnes which was filled with imports.

NATIONAL RICE POLICIES AND DEVELOPMENT STRATEGIES

Rice policies

The main thrust of government policies for increased rice production under the Medium-Term Agricultural Development Programme include: i) the exploitation of the vast lands of the inland valleys and swamps (see Figure); ii) a reduced emphasis on conventional irrigation schemes; and iii) increased research and technology transfer aimed at an efficient utilization of agricultural inputs.

RICE PRODUCTION PROGRAMME

Cereal production

Rice, maize, millet and sorghum are the four main cereals produced and consumed in Ghana (Table 1). In terms of total output of cereals (i.e. 1.6 million tonnes/year) maize contributed 59 percent, sorghum 19.6 percent, rice 10.8 percent and millet 10.6 percent.

Major rice production ecologies

Rice is produced in all the ten regions of Ghana, covering all the major ecological-climatic zones, including the Interior Savannah zone, the High Rain Forest zone, the Semi-deciduous Rain Forest zone and the Coastal Savannah zone. Within each agro-ecological zone there are distinct rice ecosystems:

• Rainfed drylands;
• Rainfed lowlands or hydromorphic;
• Inland swamps and valley bottoms; and
• Irrigated paddies.

The rainfed ecology (i.e. drylands and lowlands) accounts for 75 percent of the production area, the irrigated ecology for 10 percent and the inland swamps and valley bottoms for 15 percent.

Production potential

Ghana has great potential to expand its present average rice production area of 89 700 ha by 200 percent if its vast area of inland valleys and swamps is fully exploited (Obeng, 1994). The greatest potential lies in the Interior Savannah zone which covers almost the whole of the northern half of the country, extending over nearly 9.32 million ha (see Figure).

The successful control of the black flies which cause onchocerciasis (river blindness), particularly in the White Volta basin, has opened up for development the vast lands of the fertile Fumbesi Valley in the Interior Savannah zone, and this has been the main factor allowing for an increase in rice area from 61 000 ha in 1990 to 89 700 ha in 1996 (Table 1).

Table 1

Output, area cultivated and yield of cereals in Ghana, 1991-1996

Source: Government of Ghana (1996).

Rice production

Yield and total output. Between 1981 and 1996, average paddy output per annum was 173.2 tonnes (Government of Ghana, 1996), within the range of 131.5 to 215.7 tonnes. In the same period the average yield increased from 1.5 tonnes/ha (1990) to 1.9 tonnes/ha (1996), equivalent to a 26.7 percent increase.

Although high yields are obtained in the irrigated ecology (i.e. 3.5 to 7 tonnes/ha) this zone represents only 10 percent of the rice area and hence has little influence on the national average yield, which is determined mainly by the rainfed ecology (i.e. 75 percent of the rice area). As a result of low yields, increased rice output in Ghana is positively correlated (r = 0.94) with increased area cultivated (Vordzorgbe, 1985).

Production constraints

For Ghana to achieve self-sufficiency in rice production, several major constraints will have to be overcome so as to enhance output in the various production ecologies.

The main production constraints in the four principal rice ecologies in Ghana have been identified (Oteng, 1994), classified and ranked in terms of severity.

Physical constraints

Physical constraints occur in all the five agro-ecological zones in Ghana and some of the major ones have been presented in Table 2.

In both the Interior and Coastal Savannah zones, the topography is gentle and undulating and lends itself to mechanization and the development of extensive farms.

Table 2

Rainfall, topography and major environmental constraints affecting rice production in five ecological zones of Ghana

In the Coastal Savannah zone, however, the main constraints to production are the presence of extensive heavy clay soils (Vertisols), which cannot be tilled with light implements such as hoes and cutlasses, and the low and erratic rainfall pattern, which frequently causes crop failures.

The main impediment to crop production in the Interior Savannah zone is the extensive occurrence of groundwater laterites. They are shallow and poorly drained, light-textured soils overlying ferruginous gravelly clay and/or mudstones and occupying about 50 percent of the soils of the Interior Savannah zone and about 25 percent of the whole country (Adu and Stobbs, unpublished).

In the High Rain Forest and the Semi-deciduous Forest zones, the main physical barrier to development is the characteristically steep relief and sometimes impenetrable vegetation cover with its prohibitive cost of development using light farm tools, such as axes and cutlasses. The valleys within these zones are often swamp areas and their dominant vegetation of thick-growth raffia palms is extremely difficult to clear for rice cultivation.

Water is a major constraint in all the ecological zones except in the irrigated ecology. In the rainfed (dryland) ecology, water is perhaps the most important single factor that dictates the failure or success of the crop. In the rainfed lowland/hydromorphic ecology, it is either the lack of water in a bad year or sheer excess of uncontrolled floods that becomes the major constraint to crop production. In the inland swamps and the coastal lagoon swamps, the main constraints are poor drainage and its attendant problems, i.e. acidity, salinity and toxicity from iron, manganese, aluminium and sulphur poisoning.

Land degradation through erosion, resulting from land clearing and development, is now considered the country's most serious environmental problem (NARP, 1994). Erosion hazards may thus present a major constraint to the expansion of the rice industry in Ghana.

PRODUCTION ECOLOGIES AND RELATED CONSTRAINTS

Rainfed dryland ecology

The rainfed dryland ecology is characteristically situated in the upper slopes of the toposequence where the crop obtains its water requirements solely from rainfall and not at all from high underground water tables.

Weed competition in this ecology is fierce as the soil environment is suitable for most upland weeds (e.g. Rottboelia exaltata; Tridax procumbens; Commelina spp. and Cleome viscosa). A low and erratic rainfall favours the growth of weeds more than the crop, hence effective weed control in this ecology is the primary requirement for successful rice cultivation and makes weeds the most important constraint in the ecology.

The cultivation of the traditional local varieties under Oryza glaberrima continue to dominate in most of the agro-ecological zones even though the yield is poor.

Following is a list of desirable attributes that justify the continued cultivation of the local varieties (e.g. Abrewabesi, Akromah, Agya Amoah, Kwame Dawo, Bakoram or Bagulam and Saka):

• tall habit and ability to compete effectively with weeds;
• tolerance of some adverse soil conditions, e.g. drought, poor fertility and acidity;
• tolerance of some diseases and insect pests;
• possession of sweet aroma when cooked.

The need to develop improved and high-yielding varieties for the ecology could hardly be overemphasized. Basologo (GR 19) and Faro 15 Gr 21 are some of the improved varieties that have been tested and released to farmers by the Savannah Agricultural Research Institute (SARI).

The major pests in the upland ecology are rodents and birds. In the Transitional, Semi-deciduous and High Rain Forest zones it is imperative to fence the crop to protect it from the large rodents, Thryonomis swindarianus or grasscutters, otherwise the whole crop could be destroyed overnight if attacked. The other equally important constraints are the low and erratic rainfall, low inherent fertility of the soils and low level of technology used.

Irrigated ecology

In terms of total size or area under rice in Ghana the irrigated ecology is less important than the rainfed lowland/hydromorphic ecology but, in terms of production stability, control of production factors and output per unit area (i.e. 3.5 to 7 tonnes/ha), it is far superior to the remaining three ecologies where average yields are 2 tonnes/ha or less.

The irrigated ecology has been studied intensively for over four decades by the University of Ghana Agricultural Research Station, Kpong, in collaboration with the West Africa Rice Development Association (WARDA), and through the International Network for Genetic Evaluation in Rice (INGER) programme several HYVs have been released to farmers, for example GRUG 6 (IR3273-P339-2), GRUG 7 (TOX 725-1-8-201-1), ITA 222, IET 2885, IET 1996 and IET 6279. The ecology also enjoys a higher level of technology than the other ecologies.

The greatest constraint to production is, however, the ever-increasing bird and rodent population, which is seriously threatening the growth of the rice industry. The problem is exacerbated by the continuous monocropping of rice season after season in the absence of a viable alternate crop in the rice basins. Meanwhile, under the National Agricultural Research Programme (NARP), efforts are being made to develop a sustainable rice-based cropping system to break the cycle of rice monocropping.

The weed problem appears to the next most important problem after pests. The most obnoxious weeds which climax in the irrigated rice culture are Ischaemum rugosum, Echinochloa colonum, Cyperus rotundus and Phyllanthus spp. The weed control problem has been worsened by the withdrawal of subsidies on agricultural inputs, and farmers are resorting increasingly to hand weeding while also reducing their farm size.

Poor infrastructures in the rice industry (e.g. combine harvesters, reapers, threshers) are seriously affecting rice output in this ecology.

Rainfed lowland/hydromorphic ecology

This ecology comprises the floodplains of rivers and is particularly extensive in the Interior Savannah zone where the topography is flat to gently undulating. It has a more favourable crop-water environment than the rainfed drylands. The water level fluctuates with the flood height and, as the floods recede, the rice crop obtains its water requirements from the raised water table. The rainfed lowland/hydromorphic ecology is responsible for more than 60 percent of the rice area in Ghana and over 80 percent of the rice area in the Interior Savannah zone where rainfall is monomodal (Table 2).

The rainfall regime covers a period of about seven months (May to November), subjecting many rice fields to long periods of inundation (Table 2). The uncontrolled floods tend to affect field operations (i.e. weed control, fertilizer application, bird control and harvesting), thus resulting in poor yields.

Weed control, water management, the unavailability of suitable varieties and adverse soil conditions are some of the major constraints in this ecology.

Inland swamps and valley bottoms

The inland swamps and valley bottoms represent vast and unexploited land and water resources for rice cultivation (see Figure). In 1989 the Ministry of Food and Agriculture initiated Valley Bottom Studies under the Agricultural Sector Review Project (ASRP), with the Crop Research Institute (CRI) as the coordinating institution in collaboration with several research institutes in Ghana. Four pilot project sites were selected in the major agro-ecological zones, viz. Besease (Rain Forest), Tolon/Yipeligu (Interior Savannah) and Aframso and Gbi-Godenu (Rain Forest, Savannah, Transitional).

The main rationale behind the scheme is that, with development of good but simple water and soil management practices, higher crop productivity could be sustained in the valley bottoms and swamps, as observed by Otoo (1994). Prominent among the major constraints encountered in the valley bottoms and swamps are a lack of suitable varieties and weed and pest problems.

CONCLUSIONS

The foregoing review shows that a considerable number of formidable constraints beset the development of a comprehensive national programme to achieve self-sufficiency in rice production. For Ghana to formulate such a programme successfully, the following suggestions may be instructive:

• An overreliance on extensive rice farming in preference to intensive rice culture as a means of increasing output should be avoided. An effort should be made to raise the national average paddy yield from 1.5 to about 2.5 tonnes/ha.
• Efforts should be geared towards increasing the production technology of the rainfed ecology if there is to be any meaningful impact on rice output, since this ecology controls 75 percent of the total rice area in Ghana.
• Intensification of research to exploit the inland swamps and valley bottoms should be pursued relentlessly, since these areas are more fertile and have a higher moisture availability than the upland ecology.
• There is a need to maximize rice output from the irrigated ecology, since factors of production are better controlled than in other ecologies. A high cropping intensity is therefore imperative except where rice is sacrificed for another crop of higher market value.
• In view of high costs of inputs, the industry will benefit greatly from subsidies and also research aimed at improving the efficient utilization of inputs, such as insecticides, herbicides and fertilizers.
• Pest population control, particularly of birds, is a major concern to farmers, and efforts should be made to liaise with the Environmental Protection Council to determine the acceptable population levels and implement the necessary control measures whenever appropriate.

REFERENCES

Adu, S.V. & Stobbs, A.R. Soil of the Nasia Basin. Soil Research Institute, Ghana Agricultural Research Station. (unpublished)

Atsu-Ahebor, U.K. 1994. Keynote address delivered at the International Seminar, Towards Rice Self-Sufficiency in Ghana, 6-7 June 1994, Akosombo, Ghana.

Government of Ghana. 1991. Agriculture in Ghana. Facts and figures. Accra, Ministry of Food and Agriculture, PPMED.

Government of Ghana. 1996. Agriculture in Ghana. Facts and Figures. Accra, Ministry of Food and Agriculture, PPMED.

NARP. 1994. National Agricultural Research Strategic Plan. Draft Report. Accra.

Nyanteng, V.K. 1987. Rice in West Africa. Consumption, imports and production with projections to the year 2000. Monrovia, Liberia, WARDA.

Obeng, H. 1994. Soils suitable for large-scale rice cultivation in Ghana. Paper presented at the International Seminar, Towards Rice Self-Sufficiency in Ghana, 6-7 June 1994, Akosombo, Ghana.

Oteng, J.W. 1994. Research strategies for improved rice production in Ghana. Paper presented at the International Seminar, Towards Rice Self-Sufficiency in Ghana, 6-7 June 1994, Akosombo, Ghana.

Otoo, E. 1994. Towards increased rice production in Ghana: research on the sustainable development of the inland valleys for rice production. Paper presented at the International Seminar, Towards Rice Self-Sufficiency in Ghana, 6-7 June 1994, Akosombo, Ghana.

Vordzorgbe, S.D. 1985. Some economic considerations in policy design for increased rice production in Ghana. Paper presented at the National Rice Workshop, Tamale, Ghana.

WARDA. 1986. Rice Statistics Yearbook. Monrovia, Liberia.

PRODUCTION ET D�VELOPPEMENT DE LA RIZICULTURE AU GHANA

Le riz est devenu un aliment important au Ghana. L'�cart entre sa production et sa consommation �tait d'environ 29 000 tonnes par an de 1992 � 1996. De 1991 � 1996, la production moyenne de paddy a �t� de 173 200 tonnes pour une superficie moyenne totale de 89 700 ha; elle provenait des cinq zones �cologiques du Ghana dont 75 pour cent correspondaient � la riziculture pluviale, 10 pour cent � la riziculture irrigu�e et 15 pour cent aux marais des vall�es int�rieures. Les rendements moyens du riz pluvial oscillaient entre 1,6 et 2,2 tonnes/ha tandis que les rizi�res irrigu�es produisaient entre 3,5 et 7 tonnes/ha.

Dans les zones de culture pluviale o� l'on cultive le riz de montagne ou de bas-fonds, le sch�ma irr�gulier des pr�cipitations freine consid�rablement la production, tandis que dans les rizi�res irrigu�es et les bas-fonds des vall�es ce sont des contraintes li�es au sol qui limitent la production: terres argileuses et lourdes, difficiles � labourer avec les simples instruments dont disposent les paysans, mal drain�es, pauvres, acides, salines et contenant du fer toxique. Les mauvaises herbes abaissent les rendements de la riziculture pluviale de montagne, la riziculture pluviale de bas-fonds et de marais dans les vall�es int�rieures, tandis que les rongeurs et les oiseaux sont les principaux ravageurs du riz irrigu�.

Les vari�t�s appropri�es manquent pour la riziculture pluviale des bas-fonds, des vall�es int�rieures mar�cageuses et des fonds des vall�es car les premi�res �tudes se sont concentr�es sur le riz de montagne pluvial et le riz irrigu�. Les autorit�s s'int�ressent s�rieusement aux marais des vall�es int�rieures et aux fonds des vall�es comme une alternative moins co�teuse que la culture irrigu�e, propre � accro�tre la production nationale de riz.

PRODUCCI�N Y DESARROLLO DEL ARROZ EN GHANA

El arroz ha pasado a ser un elemento importante de la alimentaci�n en Ghana. La diferencia entre la producci�n y el consumo de arroz fue de unas 29 000 t/a�o entre 1992 y 1996. Entre 1991 y 1996, la producci�n media de arroz fue de 173 200 t en las cinco zonas ecol�gicas de Ghana, con una superficie media total de 89 700 ha, de la que el 75 por ciento correspondi� a tierras de secano, el 10 por ciento a tierras de regad�o y el 15 por ciento a valles pantanosos del interior. Los rendimientos medios del arroz de secano variaron entre 1,6 y 2,2 t/ha, mientras que los del arroz de regad�o estuvieron comprendidos entre 3,5 y 7,0 t/ha.

Las lluvias y su distribuci�n irregular son las principales limitaciones a la producci�n de arroz en zonas de secano de tierras altas y bajas, mientras que los suelos arcillosos compactos, dif�ciles de labrar con las herramientas sencillas de los agricultores, el drenaje deficiente, la escasa fertilidad, la acidez, la salinidad y la toxicidad por exceso de hierro del suelo son las principales limitaciones a la producci�n de arroz en las ecolog�as de regad�o y de los valles pantanosos del interior. Las malas hierbas reducen el rendimiento del arroz en las tierras altas y bajas de secano y en los valles pantanosos del interior, mientras que los roedores y las aves son las principales plagas del arroz de regad�o.

En las tierras bajas de secano, las zonas pantanosas del interior y el fondo de los valles hacen falta variedades adecuadas, dado que los estudios realizados anteriormente se concentraron en las ecolog�as de tierras altas de secano y en las de regad�o. El Gobierno est� prestando gran atenci�n a las zonas pantanosas del interior y las ecolog�as de los fondos de los valles para aumentar la producci�n nacional de arroz con un costo menor que en las tierras de regad�o.