Agrobiodiversity Endangered by Sugarcane Farming in Mumias and Nzoia Sugarbelts of Western Kenya

Full Length Research Paper

Agrobiodiversity endangered by sugarcane farming in Mumias and Nzoia Sugarbelts of Western Kenya

Godfrey Wafula Netondo1*, Fuchaka Waswa2, Lucy Maina2, Tabitha Naisiko3, Nelly Masayi4 and Josephine K. Ngaira4

1Department of Botany and Horticulture, Faculty of Science, Maseno University, P. O. Box 333- 40105, Maseno, Kenya. 2Kenyatta University, P. O. Box 43844-00100, Nairobi, Kenya. 3Uganda Martyrs University, P. O. Box 5498, Kampala, Uganda. 4School of Environment and Earth Sciences, Maseno University, P. O. Box 333 – 40105, Maseno, Kenya.

Accepted 28 April, 2010

Commercial sugarcane farming has been practised in western Kenya for nearly forty years. This monocultural land use is associated with loss of natural vegetation and cropland, thus undermining food security status of a place. Further, sugarcane farming is a major contributor to loss of biodiversity in western Kenya. This study was therefore aimed at determining the long-term effects of sugarcane farming on indigenous food crops and vegetables in Mumias and Nzoia sugarbelts of western Kenya. Up to 188 respondents in three divisions of Mumias and 178 respondents of three divisions in Nzoia were purposively selected. These included small-scale and large-scale farmers. Data were collected using questionnaires, Participatory Rural Appraisal tool, interviews and field observations. Secondary data were obtained from documented materials. Land under indigenous food crops and vegetable has been declining since the introduction of sugarcane. Indigenous food crops and vegetable cultivation by farmers in the sugarbelts has been declining. Furthermore, some farmers have abandoned the growing of these crops altogether. Our results imply that sugarcane farming is a major contributor to agrobiodiversity erosion, but that there are also other important reasons such as change of consumer preference, land fragmentation, climate variability among others. In order to curb further loss of biodiversity, efforts should particularly focus on food crops and livelihood diversification and adoption of farming technologies such as agroforestry.

Key words: Biodiversity, farming, indigenous crops, monoculture, Western Kenya.

INTRODUCTION

Biodiversity refers to all species of plants, animals and competitors (Boef, 2000). In agricultural systems micro organisms existing and interacting within an biodiversity performs ecosystem services beyond ecosystem (Upreti and Ghale, 2002; Vandermeer and production of food, fiber, fuel and income. Biodiversity is Perfecto, 1995; Pimentel et al., 1992). Biodiversity necessary in the recycling of nutrients, control of local performs key ecosystem services including provision of microclimate, regulating of local hydrological process, food, shelter, oxygen and soil enrichment. Apart from regulation of abundance of undesirable organisms and boosting ecosystem productivity, biodiversity contributes detoxification of noxious chemicals (Altieri, 1994). to ecosystem resilience and stability. Agrobiodiversity, a Sugarcane can be considered as the single most subset of biodiversity, includes all crops and livestock, important cash crop extensively grown in the Lake their wild relatives and all interacting species of Victoria basin of Kenya and Uganda. In Kenya sugarcane pollinators, symbionts, pests, parasites, predators and is commercially grown in Western and Nyanza provinces, primarily by small scale farmers followed by large-scale farmers and company/factory nucleus estates (Gok, 2002). While setting up infrastructure for sugarcane *Corresponding author. E-mail: [email protected]. farming and processing, minimal input is considered in Tel: +254-57351622 Ext. 3224. Fax: +254-573515221. terms of their impact on biodiversity. Land availability for

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Figure 1. Location of Mumias and Nzoia Sugarbelts in Western Kenya. The shaded colour represents the nucleus estate of the sugar companies while out grower farmers occupy the surrounding areas of each nucleus estate. The sugar factories are within the nucleus estates.

subsistence farming and agricultural diversification as Purposive and stratified random sampling techniques were used to well as biodiversity conservation is not considered select the respondents who included both small scale and large (Mallawaarachchi et al., 2001). For instance, sugarcane scale farmers. Primary data were collected using researcher administered questionnaires (188 and 178 respondents for Mumias farming led to the reduction of Melaleuca ssp and the and Nzoia, respectively), and Focus Group Discussions (FGD) eucalyptus tree species in Australia (Johnson, 2000). involving thirty individuals who were selected with the assistance of Saving the remaining world’s biodiversity has become an local authorities. Both gender and age factors were put into important public policy issue in the international, regional, consideration. Trend on changes in crop species were assessed by and national level. partitioning periods into five year intervals. Transect walks were used to augment the data collected. Data were analyzed using It is widely recognized that if the remaining biodiversity descriptive statistics focusing on frequency distribution, regression is allowed to disappear as a result of socio-economic and Pearson’s chi-square tests. Chi-square analysis was performed activities such as sugarcane cultivation, people’s to compare the effect of sugarcane on growing of food crops and livelihoods will be at stake (Alcamo et al., 2003). This indigenous vegetables. In all cases the SPSS statistical package biodiversity, especially biological resources form a basis was used. for global as well as national economic and ecological security. So far no tangible research has focused on the impact of sugarcane farming on agrobiodiversity in RESULTS AND DISCUSSION Kenya. This explains the focus of this paper on the effects of sugarcane farming on agro-biodiversity in Crops grown before sugarcane introduction Mumias and Nzoia sugarbelts in western Kenya, particularly the long term effect of sugarcane farming on Before sugarcane farming was introduced in Nzoia indigenous food crops and vegetables. sugarbelt, maize and cassava were the most cultivated crop according to the respondents at 84.5% and 84.4%, respectively (Figure 2a). This was followed by sorghum METHODOLOGY (76.3%), sweet potatoes (72.8%), and bananas (53.2%).

The study was carried out in 2007 in Matungu, East Wanga, and In Mumias, Cassava, Finger millet, Millet (sorghum), Mumias in the Mumias sugarbelt and Kanduyi, Webuye and Sitikho bambara groundnuts among others were grown by farmers divisions in the Nzoia sugarbelt, of Western Kenya (Figure 1). (Figure 2b).

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Figure 2a. Crops grown in Nzoia sugarbelt before sugarcane were introduced.

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Figure 2b. Crops grown in Mumias sugarbelt before introduction of sugarcane.

Our data, in agreement with Nekesa and Meso (1997) Effect of sugarcane farming on land size under indicate that traditional food crops were abundant in the indigenous crops area before sugarcane was introduced. Crops such as cassava, finger millet, sorghum, sweet potatoes, The mean size of land in Mumias sugarbelt under all bambara groundnuts and simsim are ecologically indigenous crops per farmer has been decreasing since adapted to the region. These crops were relied upon for 1960s from about 9.8 acres to about 4.6 acres in 2000s food security because they are highly nutritious, and can which is a two fold decline of the total land under withstand environmental stressors such as drought and indigenous crops (Figure 3a). The average acreage per inadequate soil nutrients. They also offered variety unlike farmer under sugarcane increased from 1970s and 1980s the current status where maize is a staple food crop, but when sugarcane was introduced but has tended to whose productivity is highly dependent on adequate decline in the 1990s and 2000s. Regression of size of rainfall. land under sugarcane and indigenous crops was highly

440 Afr. J. Environ. Sci. Technol.

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Figure 3a. Mean size of land under sugarcane and indigenous crops (combined) in Mumias sugarbelt from 1960s to 2000s.

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Figure 3b. Mean size of land per farmer under sugarcane and traditional crops in Mumias sugarbelt between 1960s to 2000s.

significant (P<0.001). In this case the land under division while sharing out between sons and selling of sugarcane continued to rise as that under indigenous part of the land. crops decreased. Similarly chi-square test between area The key determinant underlying this trend is population under sugarcane and indigenous crops was also highly pressure leading to fragmentation of land. Some farmers significant (p<0.000). This shows that there is a strong may also have started realising that sugarcane farming is relationship between sugarcane farming and the not as lucrative as before and hence abandoned the reduction in indigenous crops. Further, land under growing of the crop. Other factors such as late harvesting sugarcane increased inversely with the size of land under and payment after harvesting may also have discouraged individual indigenous crops such as simsim, finger millet, farmers from expanding acreage of sugarcane. On the bambara groundnuts, sorghum, cassava and sweat other hand, land under indigenous food crops reduced in potatoes (Figure 3b). Similar trends were observed for the 1970s and 1980s. However, in the 1990s and 2000s Nzoia sugarbelt (data not shown). The acreage under the decline in area under individual food crops eased. sugarcane increased due to the introduction and The farmers on realizing that sugarcane farming is not as promotion of monocultural sugarcane farming concomi- profitable may have turned to growing some of the food tant with the construction of Nzoia and Mumias sugar crops; particularly maize which is a staple food crop. factories in the 1970s. However, in the 1980s the sizes Although acreage of traditional food crops such as began to reduce due to many factors such as land sub- sorghum and millet and vegetables have been shrinking

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Figure 4a. Trends in major crops grown in the Nzoia sugarbelt since 1960s to 2000s.

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Figure 4b. Trends in major crops grown in the Mumias sugarbelt since 1960s to 2000s.

as a result of conversion of the land to sugarcane Effects of sugarcane farming on the cultivation of growing, some crops such as groundnuts and Bambara indigenous food crop and vegetables groundnuts are still being grown by some farmers because they are usually intercropped with sugarcane in While the cultivation of sugarcane increased over the the early stages of sugarcane growing up to about one period 1960s to 2000s that of the indigenous crops (1) meter height. The intercropping may have contributed reduced (Figures 4a and 4b). One of the most affected to the sustenance of the indigenous crops like bambara crops in Nzoia sugarbelt for the period is finger millet groundnuts in the study area (Nekesa and Meso 1997). whose cultivation declined from about 60% to about 19%,

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e f s t s h d a a n w e t le le e la lo v n a a r p l a a K h e p a e r ts d w r m l a n h n o e n m a g e C id te i a ic i l p u k r n S J m le f n S u b A a P ta rc e f g A e V Figure 5a. Trends in the growing of indigenous African leafy vegetables in the Nzoia sugarbelt since 1960s to 2000s.

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Figure 5b. Trends in the growing of indigenous African leafy vegetables in the Mumias sugarbelt since 1960s to 2000s.

translating to about 40% reduction. Others are cassava, pig weed. sorghum and bambara groundnuts. In Mumias sugarbelt The change in indigenous vegetables in relation to finger millet, sorghum and simsim were the most affected sugarcane were highly significant (p<0.05) indicating that by sugarcane farming (Figure 4b) sugarcane farming contributed to the decline of In Nzoia some indigenous vegetables such as indigenous vegetables in Nzoia and Mumias. The decline spiderplant, African nightshades, and vine spinach have in cultivation of the crops may have been due partly to been declining since 1960s (Figure 5a). Some vegetables the wrong perception that sugarcane farming is more like jute mallow increased from 1960s to 1990s before profitable than the food crops (Waswa et al., 2009). The showing a slight decline in 200s.Vegetable amaranth study indicates that expansion of sugarcane farming does not show any clear pattern. Apparently more poses a high risk to the existence of varietal diversity of farmers have been growing cowpeas, as indicated by the indigenous vegetables such as pumpkin, African night- steady increase since 1960s. In Mumias, remarkable shade, amaranths and food crops like sorghum, finger declines occurred for African nightshades, vegetable millet, cassava and sweet potatoes. This is exacerbated amaranth and African kale (Figure 5b). Some reduction by farmers abandoning the growing of the crops. Most also occurred in jute mallow, spiderplant, pumpkin and indigenous crops have many landraces with unique

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a s t ts ts s s s s s v e le u u m im n n t le it a o il n u s a a o u s t m d n h e e ro b r s ta d rg im B b ta F a o r n n o w e C p e u u S a o g t g ro ro S y rr e e in g o V e F G S A ra w a S b m a B

Figure 6a. Percentage of farmers who have abandoned cultivation of specific food crops in Nzoia sugarbelt.

qualities. The farmers also have personal networks Nzoia sugarbelt are cassava and sorghum, despite their through which they disseminate local varieties/landraces. ecological suitability (Figure 6a). For Mumias most Furthermore, they practice intercropping, fallow cropping farmers have abandoned finger millet, simsism, sorghum and relay cropping. All these traditional practices and bambara groundnuts (Figure 6b). Reasons for contribute to maintenance of crop and vegetable deserting cultivation of food crops were varied. Whereas diversity. However, contemporary forms of agriculture, 89.4% respondents in Mumias cited sugar cane farming particularly monoculture has contributed to accelerated as the main cause, only 26.7% respondents gave the agrobiodiversity erosion by replacing these traditional same reason for Nzoia (Table 1). However nearly equal faming technologies, which mostly encourage crop number of respondents cited land fragmentation/limited diversification. As indicated by Upreti and Ghale (2002) land at 34.9 and 34.5% for Mumias and Nzoia, and FAO (2004) that commercialization of agriculture is respectively. Soil infertility (27.5%) featured prominently the main cause of food crop diversity loss, sugarcane as reason for abandoning the food crops in Mumias but farming in the study area is contributing significantly to was not cited in Nzoia. Other reasons include pests and the same. These indigenous crops and vegetables were diseases, change of taste and preference, low grown mainly for local consumption and were also of production, labour intensive, lack of seeds, lack of ready medicinal value as well as festivals and making of market, change of climate and low returns, most of which alcohol. The inputs such as chemical fertilizers, pesti- were cited by less than 10% of the respondents. cides and insecticides are minimal (Upreti and Ghale, The abandonment of food crops and vegetable culti- 2002). The spatial distribution and exchange of local vation has contributed to their disappearance in Mumias varieties through seeds and other propagation materials and Nzoia sugarbelts and by extension all other sugar- have been disrupted, further contributing to loss of variety cane growing regions in the Lake Victoria region. The The decline of traditional varieties/landraces of food roles played by other factors cited by the farmers (Table crops and vegetables is called genetic erosion (Picone 1) are equally important. In this study it was reported that and van Tassel, 2002). This eventually leads to loss of cassava was affected by cassava mosaic virus forcing genetic diversity which has the impact of loss of genes many farmers to abandon growing it. Generational necessary for improvement of food crops against pests, preferences mainly involving youths indicate that they diseases, environmental stresses like water deficit and lack interest in some crops such as bambara groundnuts, salinity. By losing landraces through sugarcane farming sorghum, simsim and finger millet. The youths also we are undermining our ability to adapt crops to future dislike the foods prepared from these crops. According to conditions, including climate change (Picone and van Liwenga et al. (2008) sugarcane cultivation renders the Tassel, 2002). soil infertile and hence cannot support crops like finger millet, thus contributing to their abandonment.

Abandonment of indigenous food crop cultivation Conclusions Some farmers reported to have abandoned growing indigenous crops. The key crops that have been There has been a decrease in land under indigenous significantly abandoned due to sugarcane farming in crops and vegetables since the introduction of sugarcane

444 Afr. J. Environ. Sci. Technol.

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Figure 6b. Percentage of farmers who have abandoned cultivation of specific food crops in Mumias sugarbelt.

Table 1. Reasons for abandoning growing of some food crops in Nzoia and Mumias sugarbelts.

Percentage of respondents Reason Nzoia Mumias Sugarcane farming 26.7 89.4 Land fragmentation/limited land 34.5 34.9 Soil infertility - 27.5 Change of taste and preference 10.5 16.4 Introduction of exotic plants - 12.7 Pests/moles/diseases 7.5 10.1 Climate variability 1.0 6.9 Lack of skills - 4.8 Labour intensive 4.8 4.8 Expensive seeds 1.9 1.1 Poverty - 0.5 Lack of ready market 3.8 - High production costs 9.5 -

in Nzoia and Mumias sugarbelts in western Kenya. The sion of genetic resources and pose a high risk of loss of cultivation of both indigenous crops and vegetables has species diversity if precautionary conservation measures shown a declining trend. Some of the affected indigenous are not instituted in time. crop and vegetable species include sorghum, finger From the foregoing it is recommended that enhancing millet, bambara groundnuts and simsim, African kale, biodiversity through various interventions is needed African nightshade, amaranths and spiderplant among urgently. This may include revegetation of farm edges, others. Whereas sugarcane farming has significantly introducing agroforestry practices such as integrating contributed to the decline of agrobiodiversity other factors strips of land in farms to provide natural habitats and have also contributed to decline in crop and vegetable enhancing technical skills in crop diversification (Kindt et diversity, including land fragmentation, soil infertility, al., 2005). This will enhance and maintain agrobiodiversity changes in consumption tastes and preferences, pests of food crops and vegetables in the sugarbelts. Further, and diseases, labour intensiveness of some crops like crop diversification should be promoted, particularly those bambara groundnuts, poor adoption of new farming that are early maturing, highly nutritious and adapted to technologies and high costs of seeds. The decline or the ecology of the sugarbelts. Farmers with small pieces abandonment of the crops and vegetables leads to ero- of land should be discouraged from growing sugarcane

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