African Crop Science Journal African Crop Science Society ISSN: 1021-9730 EISSN: 2072-6589 Vol. 7, Num. 4, 1999, pp. 613-623

African Crop Science Journal, Vol. 7. No. 4,  pp. 613-623, 1999                                                           

Short Communication

CULTURAL PRACTICES AND PRODUCTION CONSTRAINTS IN SMALLHOLDER BANANA-BASED CROPPING SYSTEMS OF UGANDA'S LAKE VICTORIA BASIN

M.M. Tenywa, M.I. Isabirye¹,  R. Lal²,  A. Lufafa  and  P. Achan
Department of Soil Science, Makerere University, P.O. Box 7062, Kampala, Uganda
¹Kawanda Agricultural Research Institute, P.O. Box 7065, Kampala, Uganda
²School of Natural Resources, Ohio State University, Columbus, OH 43210, USA 

Code Number: CS99053

ABSTRACT

Identification of environmentally-sound options for agricultural resource management  is necessary to obtain food security for smallhold farming communities in Uganda.  Qualitative and quantitative appraisals were conducted in Bukoto county, Masaka district to assess the socioeconomic and biophysical status of the banana and coffee farming system.  Three main hypotheses were tested: the banana-coffee system is relatively static; the farmers production and socioecological goals are constrained by  socioeconomic and biophysical factors; and that the system consists of interacting components.  In order to test these hypotheses a participatory rural appraisal (PRA) was conducted, followed by a systematic land resource evaluation and structured household interviews . The study revealed significant changes in the system in terms of major activities, nature and status of resources and constraints encountered in pursuit of production goals. Although coffee is still an important cash crop and banana an important food crop, other income-generating activities (e.g. growing of beans, cassava and vegetables, brick-making, local retailing) have gained significant importance among farm households. In order of importance, coffee ranks first followed by beans and bananas, respectively. The notable loss in status by banana  to the third position was attributed to several factors including nutrient depletion (ettaka likadiye), unreliable rainfall and increased infestation of pests and diseases.  Over the years, low banana yields have been increasingly compensated by expansion of production area rather than unit productivity. There is a general consensus among the farmers that the soils are no longer productive due to continuous cultivation and soil erosion and this was confirmed by the notable decrement in soil quality.  pH, CEC, P and K in top soil (0-20 cm) decreased from 5.1, 13.4 cmol kg^-1, 9.7 mg kg^-1 and 0.2 mg kg^-1 to 4.7, 6.09 cmol kg^-1, 1.38 mg kg^-1 and 0.07 mg kg^-1, respectively.  The cause of continuous cultivation is a high population pressure that creates land fragmentation while soil erosion is attributed to  persistent failure by farmers to adopt soil and water conservation practices. All the farmers visited were aware of the importance of soil and water conservation (mulching, contour bunds, diversion channels, soak pits and agroforestry) but were constrained by labour, time and insufficient supply of inputs (e.g.,  mulch materials).  There must be soil fertility status improvement, erosion control, integrated pest management (IPM) and stabilisation of soil moisture status for sustainable agricultural productivity to meet the demands of the increasing population.

Key Words: Agricultural intensification, coping mechanisms, soil erodibility, soil erosion, soil and water conservation practices, PRA 

RÉSUMÉ

L’identification des options qui protègent l’environnement dans  la gestion des resources agricoles est nécéssaire pour atteindre la sécurité alimentaire des communautés des petits ménages agricoles en Uganda.  Des évaluations qualitatives et quantitatives ont été conduites au département de Bukoto, district Masaka pour évaluer la situation biophysique et socio économique du système agricole banane et café.  Trois principales hypothèses ont été testées: Le système banana-café est relativement statique; les productions des agriculteurs sont limitées par les facteurs biophysiques et économiques; et le système consiste des composantes interactives.  En vue de tester ces hypothèses une évaluation rurale participative (ERP) a été conduite suivie d’une évaluation systématique des resources de terre et des interviews structurés des ménages.  L’étude a révélé des changements significatifs dans le système en terme de principales activités, la nature et l’état de resources sur les contraintes rencontrées dans la poursuite des objectifs.  Bien que le café est  encore une importante culture de revenu et la banane une importante source alimentaire, d’autes activités génératrices de revenus (e.g. la culture du haricot, manioc et légumes, faire des briques, la vente locale en détail) ont atteint d’importances significatives parmi les activités ménagères de la ferme.  Dans l’ordre d’importance, le café vient en première position suivie des haricots et de la banane respectivement.  La perte notable de la situation par la banane à la troisième position a été attribuée aux multiples facteurs dont l’épuisement en éléments nutritifs (etaka likadiye), des pluies rares et accumulation des maladies et pestes.  Au cours des années, les faibles productions de la banane ont été de plus en plus compensées par l’expansion de la superfice de production plutôt que par la productivité par unité.  Il ya un compremis général des les agriculteurs que les terres ne sont plus productives suite à une culture continue et à l’érosion du sol et ceci a été confirmé par la diminution de la qualité du sol.  pH, CEC, P et K dans la partie supérieure du sol (0-20cm) ont diminué de 5.1, 13.4 cmol kg^-1, 9.7 mg kg^-1 et  0.2 mg kg^-1 à 4.7, 6.09 cmol kg^-1, 1.38 mg kg^-1 et 0.07 mg kg^-1, respectivement.  La cause de la culture continue est la démographie galopante qui cause une fragmentation des terres alors que l’érosion est attribuée à la non-adoption des techniques de conservation de l’eau et du sol.  Tous les agriculteurs connaissaient l’importance de la conservation de l’eau et de la terre (paillage, les terraces, agroforestrie) mais ont des contraintes du travail, temps et l’approvisionnement insuffisant des intrants (ex. materiel de paillage).  Il doit y avoir un état d’amélioration de la fertilité du sol, contrôle d’érosion, la gestion intégrée de pestes (IPM) et la stabilisation de l’humidité du sol pour une productivité agricole soutenue pour faire face aux demandes d’une population croissante.

Mots Clés:   Intensification agricole, mécanismes chaperon, érodibilité du sol, ERP

 Introduction

The gap between potential and actual productivity of the banana-coffee farming system within the Lake Victoria Basin is a serious concern among farmers and agricultural planners alike.  Rubaihayo (1992), using banana harvest index as a parameter to measure change in this farming system, reported yields  of  5.58 t ha^-1 against a potential  of  60  t ha^-1.  Bekunda and Woomer (1996) reported similar observations and attributed the declining yields to a complex interaction of pest/diseases and land degradation. A diagnostic survey by the National Banana Programme to determine yield losses by various problems reported Black sigatoka (37-40%), nematodes (19-51%), banana weevil (20 - 60%) and soil fertility depletion (50-73%) as the causes of declining yields. In order to gain a broader understanding of the system and how the factors implicated in productivity deterioration interact, a participatory rural appraisal (PRA) was conducted in central Uganda to assess the socioeconomic and biophysical status of the banana-coffee farming system.

Methods

A combination of methodologies, namely; PRA, structured household interviews and systematic land resource evaluation (FAO, 1990) were used in Bukoto county in Masaka district representing an erosion prone area of the Lake Victoria Crescent. The study site lies between 0025'N, 31041'S and is located  approximately 12 kms from Masaka town on the southern axis on the road to Tanzania.

Preliminary identification of the zone was guided by UNEP (1987) Global Resource Information Database (GRID) soil erosion hazard map. The selection of the specific study site was confirmed during a rapid rural appraisal (RRA) of the district with the help of agricultural staff at the district, together with local administrators.

This zone is located on the eastern  African plateau (1,150 m - 1,400 m a. s.l) between the western and eastern African rifts on an extremely old (mid- to end-tertiary) Buganda surface characterised by hills and ridges that are highly dissected by streams (Harrop, 1970). The native vegetation is forest savannah and moist thicket on the uplands and papyrus in valleys.  Natural vegetation has been greatly modified by human activities. Land use varies depending on rainfall distribution, soils, landform and population size.  Average annual preciptation is 1218 mm distributed bimodally (Yost and  Eswaran, 1990). The first and longer rainy season occurs between March and June while the second and shorter rainy season occurs between August and November. The average annual temperature is 21.5ºC.

Soil type varies widely with elevation and landscape position and  is  of medium productivity with low charge and nutrient holding capacity. The soils can be grouped into three broad categories. The hillcrest soils (USDA: Plinthic Kandiudults; FAO: Petroferric luvisols) are very shallow residual soils covering approximately 30% of the total land area and found on the steeper slopes where erosion is severe. They are commonly classified under loamy skeletal families because of presence of ironstone outcrops or reworked plinthite. In general, they are covered by pastures and used for grazing.

Pediment-side slopes (USDA: Arenic Kandiudults; FAO:Chromic luvisols) are very deep, progressively becoming shallower towards the shoulders and covering over 60% of the total area and commonly cropped to coffee, bananas, vegetables and sugarcane.

Floodplains and valley soils (USDA: Eutric Mollisols; FAO Mollic gleysols) cover about 10% of the land area. The flood plains and valleys where encroached are used largely for grazing.

As an entry and premise for subsequent studies in Bukoto county, a participatory rural appraisal (PRA) was conducted in Kanabukuliro village. The village has a population of about 325 residents constituting 65 households. Information was generated from the members of the community through focus group discussions and dialogue.  A number of PRA tools were used; historical profile, mapping and diagramming, transect walks, semi-structured interviews, ranking (pairwise, matrix and wealth), seasonal calendars and diagrams of the farming systems. 

Historical profiles were used to assess trends in food production, soil fertility and rainfall over the last 30 years. Mapping and diagramming was used to locate the biophysical features, soil types and landuse on the ground.  Transect walks assessed spatial variations in settlement patterns, vegetation, crops and soil types. Semi-structured interviews were used alongside other tools to establish production opportunities, major  constraints and existing  coping mechanisms. Pairwise ranking identified major economic activities, crops and agricultural production  constraints, while matrix ranking examined crop suitability and constraints of different soil types. Wealth ranking stratified the community in terms of availability of the factors of production and ability to avert risks. Seasonal calendars established the temporal distribution of rainfall, food and labour while the farming system diagrams evaluated inter-relationships within and between system components (Szymanski et al., 1998).

For indepth characterisation of types, quality and distribution of existing soil and water conservation practices and governing factors,  structured interviews were conducted in 30 households. Whilst the semi-detailed land evaluation covered 30 km² and the detailed survey  5 km².

Results and Discussion

Crop production is still the major economic activity practiced by over 80% of households in the area. Farming systems have undergone marked changes since described by Parsons  (1970), particularly in terms of important economic activities. Participatory value judgement by 24 female and 12 male farmers using pairwise technique ranked the main economic activities in their order of importance as crop production, animal production, contract labour services, retail business and brick laying (Table 1). Previously, farmers were largely involved in crop production and, to a less extent, rearing of animals (Parsons, 1970).

Similarly, changes have occurred within the  crop production system (Table 1). For example, coffee and beans are said to have overtaken bananas in terms of food security and  income generation. Nonetheless, bananas ranked third in order of importance and are still considered the major food staple, occupying a significant (50%) portion of the land.  Previously, the banana-coffee cropping system was dominated by bananas followed by coffee then other annual crops (e.g., maize, sweet potatoes, beans, cassava, sorghum)(Parsons, 1970). Hardy and low soil fertility tolerant crops (e.g. sweet potatoes and cassava) have increasingly become important in the farming system. In addition, a wide range of horticultural crops (e.g., pumpkins, cabbages, yams, tomatoes, eggplants)  are grown and surpluses marketed (Table 1).

Table 1. Pairwise ranking of major economic activities, crops grown, factors responsible for crop yield decline and associated agricultural production constraints in a selected microcatchment  of the Lake Victoria Crescent

The emergence of unknown or less important activities and  crops is a response to decline in crop yields. Results from a participatory historical food production trend analysis dating back to 1930’s and involving key informants above 70 years in age confirmed reports of crop yield reductions. Per capita food production of bananas declined progressively over the years while total banana production is believed to have increased till recently (early 1990s) through expansion of production area. These findings are in agreement with the report on banana production in Uganda in the period 1970-91 in which per capita production  decreased from 9  to 5.5 tons  ha^-1 while total production area increased from 0.9 to 1.5 Mha (MAAIF, 1992).

The crop yield decline over the years was attributed to several factors ranked by pairwise technique (Table 1). Population growth ranked first and is perceived by farmers to be the major cause of crop yield decline. In 1969,  the population of Masaka was 82 person km^-2 compared to 152 persons km^-2 in 1991 (MPED, 1992). Population growth results not only in smaller  land holdings through fragmentation but also diminished opportunity for  traditional farming practices. All farmers that participated in group discussions conceded not to be practising fallowing due to scarcity of arable land. These findings are in concordance with other  reports (Rubaihayo, 1992; Bekunda and  Woomer, 1996; Gold et al., 1999) in which a complex interaction of land degradation, and pests and diseases were implicated as the main cause of banana yield decline. Noteworthy is that changes in rainfall pattern is currently perceived by farmers to be a major cause of crop yield decline. Also, lack of knowledge was highlighted as a cause of crop yield decline. For example, the method of ploughing was across rather  than along the slope contour  for ease of labour.  Most farmers were not aware that ploughing down the slopes encourages soil erosion but were willing to abandon the practice  for the recommended contour cultivation.

The study revealed that farmers have a wealth of knowledge of their environment (Fig. 1), a variety of constraints to crop  production (Table 1), and  a range of strategies to cope with them (Fig. 2). The group discussions revealed that the social problems associated with decline in food production include malnutrition (especially in children), increase in poverty,  and crime (food thefts) (Fig. 2). The strategies developed by farmers to cope with declining productivity were mainly migration, adoption of improved technologies, and pursuit of off-farm income (Fig. 2).

Farmers who have remained on the land are adopting a form of agricultural intensification. Agricultural intensification is a process by which fixed or smaller land area is used to meet increasing demands for food by manipulation of either the land and/or crops grown as depicted in Figure 2. According to Pender (1998) and Scherr  (1999), there is a critical stage along the soil resource degradation cycle at which the farmer is forced to respond to productivity decline. Results from the semi-structured interviews revealed that all the farmers interviewed were aware of the importance of soil and water conservation practices and 50% of the population have at least one conservation practice on the ground (Table 2.). This is in contrast to the report by Parsons (1970) that soil conservation measures are rarely applied, nor needed where fields are small. The common practices include mulching, contour bands, diversion channels, soak pits and agroforestry. Soil management strategies used by farmers fell into two general categories; conservation and improvement (Fig. 2).   All farmers visited with banana monocrop were found to mulch their fields, although the quality and quantity of mulch varies widely. For example, 57% of the farmers were ranked under “poor management” with only 20 and 23% ranked under good and fair management, respectively.

Table 2.  Percentage distribution of household with different soil and water conservation practices across land use

¹SWC practice = soil and water conservation practice

Likewise all farmers with banana-coffee intercrop practise mulching only that the quality and quantity of the mulching material is poor  as compared to that used in the banana monocrop. Coffee is generally not mulched except for the clonal type. In terms of construction of contour bands, 80 %, 12.5 % and 11% of the farmers growing banana monocrop, banana-coffee intercrop and coffee, respectively, had at least 1–2 contour bands. The dimensions of these structures were generally similar in all the above land use types. Diversion channels, soak pits and agroforestry are used by a few farmers. The low level of soil and water conservation practices was attributed to several constraints including labour, time and lack of inputs (e.g., mulch materials).

A significant proportion (50%) of the farmers who pursue off-farm income (e.g., retail business, brick making, contractual labour service) invest some of their income into the farm.  The soil improvement efforts included better recycling of on-farm resources within and between system components and addition of external inputs (Fig. 1). Additionally, the off-farm income is used to purchase food from other farmers. Bekunda and Woomer (1996), contend that farmers are familiar with, and practice, a range of soil fertility management strategies and suggest that many farmers are able to change  strategies as conditions warrant.

In conjunction with soil management, farmers make deliberate efforts to select and arrange crops  both in space and in time to maintain productivity (Figs. 1 and 3) in terms of efficient utilisation of nutrients and resistance to natural hazards. Table 3 shows crop suitability for the major soil types as perceived by farmers and the soil  exploited. For example, farmers with relatively more fertile loam soil Kiwugankofu have a wider variety of crops (coffee, bananas, beans, cassava and sweet potatoes) to choose from compared to those with stony reddish loam Limyufu elyoluyinja that reportedly is unable to  support a crop.  Depending on the range of suitable crops, four main intercropping  (spatial) systems were identified in the study area, namely; banana/coffee, banana/beans/maize, maize/beans, and cassava/beans/maize. 

Table 3. Crop suitability of the major soil types in a selected micro-catchement of the Lake Victoria Basin

In terms of temporal arrangement, timing of planting and rotations were reported to be important. The bimodal rainfall pattern allows production of two crops a year. Planting is normally conducted after two  heavy showers. Most farmers reported use of crop rotations as a tradition rather than for soil improvement  or for disruption  of pest and disease cycles. The distribution of different production strategies along the transect as a function of biophysical factors is given in Figure 3. Yams and sugarcane were said to be grown in reclaimed wetlands.

The strategy adopted to cope with the declining yields depends on a host of environmental, biophysical and socioeconomic constraints as ranked in Table 1. Currently, farmers perceive changes in rainfall pattern as the most important constraint to increased production. Most agriculture in Uganda is rainfed.  A rainfall seasonal calendar derived with the farmers revealed that rainfall is distributed in two seasons (March to June and August to December) with May and October as the peak months. This trend closely corroborate scientific records  reported by Yost and Eswaran (1990). However, there was a general consensus among farmers that over the years, rainfall has become increasingly unreliable and unpredictable both in amounts and intensities across the seasons. Rainfall distribution also influences other crop husbandry practices such as weeding. For example, in the longer rainy season (March to May), weeding of bananas, coffee and annual crops may be done as many as three times yet with less rainfall, as in  the short rainy season (September to November), only one weeding may be necessary.

The key biophysical constraints to sustainable production were ranked in their respective order of importance as changes in rainfall pattern, soil exhaustion (ettaka likadiye), soil erosion (mukoka), and pests and diseases (Table 1). This finding is particularly interesting considering that the banana-coffee system was in the past described to occur on the most fertile parts of Uganda, centred on the northern shores of Lake Victoria (Parsons, 1970).  Group discussions revealed that soil fertility problems hitherto less pronounced are currently recognised as the major production constraint  (Fig. 4 ). In addition to soil depletion through crop mining highlighted by Bekunda and Woomer (1996) and Gold et al. (1999), soil erosion was fourth among the key constraints. The soils in the area were considered to be of low to medium fertility on the basis of appearance and vigour of the crops. Five main distinctive types of soils were identified (Table 3); Kiwugankofu (porous loam), Luyinjayinja (stony loam), Lubumbabumba (clayey), Limyufu elyoluyinja (stony reddish loam), and Limyufu ejimu (reddish fertile loam).

Each of the soil types exhibits varying degrees  of proneness to the major constraints. Results from a matrix ranking of the constraints by farmers for each soil type revealed that the stony loam (Luyinjayinja) is most constrained (Table 4). Porous loam (Kiwugankofu) and clayey (Lubumbabumba) registered the highest and lowest erodibility rankings, respectively. Of importance to banana and coffee production are Kiwugankofu and Limyufu ejimu soil types, which constitute the Arenic Kandiudalts (USDA) an equivalent of Chromic luvisols (FAO). Results from the land resource evaluation confirmed farmers’ beliefs of decrement in soil quality of this unit (Table 5). For example pH, CEC, P and K in top soil (0-20 cm) decreased from 5.1, 13.4 cmol kg^-1, 9.7 mg kg^-1 and 0.2 mg kg^-1 to 4.7, 6.09 cmol kg^-1, 1.38 mg kg^-1 and 0.07 mg kg^-1, respectively, which are rated as marginally suitable for bananas (FAO, 1993). The notably higher top soil organic carbon content in this unit compared to that reported by Radwanski (1960) could be attributed to the traditional mulching (which upon decay increases organic content) practice in banana and the leaf fall from coffee.

Table 4. Matrix ranking of agricultural production constraints as perceived by farmers for the major soil types in a selected micro-catchment of  the Lake Victoria Basin

Key: 4. Very serious; 3. Serious; 2. Not serious;  and 1. Not applicable
Note: In reference to changed rainfall pattern, the level of seriousness refers to the duration after which the prevalent crops on the soil start to succumb to moisture stress at the end of the rain season

TABLE. 5. Selected soil quality parameters in Bukoto County during the current study and earlier (1959)

  *Source: Radwanski (1960)

Other biophysical constraints were found to relate to crops directly, but indirectly aggravated the soil problems. For example, bananas were reported to be vulnerable to streak virus disease (BSV), weevils (Cosmopolites sordidus) and nematodes (especially Radopholus similis) while cassava is prone to mosaic  (CMV) disease. Farmers make deliberate efforts to procure more resistant lines but are constrained by socioeconomic factors. In addition, some crops require specific seedbeds (Table 6). The specific reason given for using the heaped seed bed was to allow for more soft soil where tubers can easily form, although sugarcane was also grown on heaped soils.

Table 6.  Wealth ranking of participating households in Kanabukuliro Village, Masaka District

The farmers take considerable effort to maintain productivity but were constrained by several factors. The major socioeconomic constraints ranked in order of importance were  land scarcity, poverty, adulteration of agro-chemicals, marketing problems and poor supply of inputs (Table 1). The current land scarcity due to population increase  cannot any longer allow further extensification to meet the increased food demands. According to Bekunda and Woomer (1996),  as the population grows and farm sizes diminish through fragmentation increased food demands are met by greater integration of farm resources. In this study, scarcity of land was reported to be the major driving factor for intercropping practice.

The majority (98%) of the farmers in the area have smallholdings and depend largely on family labour. Their major sources of income were ranked in order of importance: sale of cash crops and food crops  when surplus is realised, sale of animals and animal products,  and contracting labour services.

Exploration of farmers perception of wealth in the area using wealth ranking techniques revealed  four ranks, namely, the rich, moderately well-off, the poor, and the very poor (Table 6).  The criteria for the ranking was mainly ownership of property.  The following categories of properties were considered; cattle, coffee plantations/trees, banana plantations, type of house, ownership of motor vehicle/bicycle, land, household properties, goats, chicken, pigs, size of family, and educated members of family.

Conclusions

The study revealed that the banana-coffee farming system as described earlier by Parsons (1970) has undergone significant changes between and within the major economic activities. Although crop production is still the preoccupation, crop yields are reported to have declined over the years.  However,  farmers are making efforts to reverse the trends but are greatly constrained by a host of environmental, biophysical and socioeconomic factors. The major causes of yield decline include population growth,  decrease per capita production area, continuous cropping, and changes in weather pattern.

Acknowledgement

We thank F. Kabango, P. Kiyemba, A. Wasswa, R. Sebadduka, R. Lutwama and  J. Amamure-Okello,  for their input. The study was funded by the Forum for Agricultural Resource Husbandry, a programme of the Rockefeller Foundation.

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©1999, African Crop Science Society

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