Urban Harvest- Research

Urban Health & Resources

Urban Harvest Projects on Urban Health and Resources:

Model reservoir to improve crop production

Clean Water, Clean Vegetables

Contribution of perishable products from UPA to the nutrition of households in Yaounde

Assessing potentials for improving waste-water management by peri-urban starch processing enterprises in North Vietnam

Quality assurance of agricultural products in peri-urban Hanoi, Vietnam

Pesticide use and pest management study of an agro-enterprise cluster based on sampaguita (jasmine) garland-making in Manila, Philippines

Study and mapping of water contamination levels at different points of the local drainage system in Yaounde, Cameroon

Health Impact Assessment and options for improvement in urban agriculture in Kampala, Uganda

Management of organic wastes and livestock manures for enhancing agricultural productivity in urban and peri-urban Nairobi, Kenya

Development of a weaning food for infants, with sweetpotato base, for poor urban families in Lima, Peru

The livelihoods study among producers in Yaounde, Cameroon, identified the importance of traditional leafy vegetables (TLVs) in local cropping systems, especially those in the valley bottoms. A separate study, led by CIRAD/IITA, “The contribution of perishable products to the nutrition of households in Yaounde”, used secondary data sources to examine the contribution of TLVs to the nutritional well-being of poor urban households. Three leafy vegetables produced in urban and peri-urban areas (cassava leaves, Vernonia and Amaranthus) were found to contribute 8% of protein and 40% of calcium to the local population. Fresh cassava roots, which are also produced locally in the main, contribute about 6% of energy to the local population. The analysis also revealed the importance of the small homegarden production systems in the city that on average, produce about 10% of cassava roots and leaves consumed in the city . Finally, the analysis clearly indicated that the caloric contribution of peri-urban and urban products is more important for the poor than the rich households.

A CIP-led project on “Assessing potentials for improving waste water management by peri-urban starch processing enterprises in north Vietnam” is assessing the possibility of partly solving the environmental agronomic effects and health aspects of using waste water from rootcrop processing and pig-enterprises. Two trials were conducted during the winter season with sweetpotato (the only important winter crop in the area) and spring trials with rice and kangkung (a vegetable crop). These first trials with sweetpotato aimed to evaluate the response of local versus introduced clones to the waste water. The spring trial was primarily designed to determine the balance between the minimum presence required of farmers in their rice fields whilst wastewater is being used, and the desired yield boost. It tested levels of wastewater application and management interventions. The rice trials indicated that significant yield increases could only be obtained with a minimum of four irrigations with wastewater. The four week period this implies may be too long a period for farmers to keep out of their fields, thus raising the need to identify other means to ensure farmer safety, if they are to benefit from use of wastewater on rice crop. On the other hand, kangkung showed significant yield increases with only two applications of wastewater, with yield increasing proportionally with additional applications. A small yield increase of 11.5% was recorded in total dry matter (DM) yield of sweetpotato, reflecting a moderate increase in fresh yield and a decline in DM with use of wastewater. No adverse effects of pests and diseases were recorded through use of wastewater, for any of the crops.

The AVRDC-CIRAD project in Hanoi, Vietnam on “Quality assurance of agricultural products in peri-urban Hanoi” terminated during 2002. The activity had both a productivity goal and an environmental/health goal, in seeking to support safe and efficient vegetable production in Hanoi. The project consisted of two components. One component consisted of the on-farm and experimental station trials evaluating alternative integrated pest management (IPM) practices and a no-pesticide treatment, and comparing these to pesticide use by farmers under two seasonal conditions (both hot, wet, summer conditions and cool, dry winter conditions). The data on use of pesticides by farmers was based on earlier survey results. Comparing the data got from the two seasons showed that there was much higher incidence of important pests (P. striolata, aphids) during the cool, dry season than in the hot, wet season. However, no clear conclusions could be drawn between the efficacy of the different treatments during the wet season due to low pest pressure. In the cool season, there was no significant yield advantage gained through heavy pesticide use in the farmers’ treatment, compared with the IPM treatments. A further finding was that the farmers’ treatment led to a dramatic reduction in beneficial insects, compared with the other treatments.

The second component assessed the use of pesticides by farmers during the two seasons, through application of a survey. Findings indicated that increased familiarity with use of pesticides led to reduced application – an indication that more intensive capacity building, perhaps through Farmer Field Schools could reduce pesticide use just by providing better information. A clear correlation was also identified between the number of different crops being grown on a farm and the amount of pesticides applied, suggesting that farmers are unfamiliar with the possible pest-management aspects of multiple cropping. Another area with a need for more participatory research by scientists and farmers is the higher application of fungicides during the dry season when fungus diseases are lower and the higher application of insecticides in the hot season when less pest pressure is evident. A follow up study by CIRAD is being proposed to look in more depth at subjective perceptions of pest-management and pesticide use by farmers. Efforts will also be made to link up with the FAO Farmer Field School (FFS) program in Vietnam to address farmers’ learning needs.

Health risks resulting from pest management and pesticide use have been the major foci of UPWARD and the University of the Philippines. They have led research in urban and peri-urban Manila, Philippines into an agro-enterprise cluster based on sampaguita (jasmine). This is the second phase of the project, which began with a livelihoods study of the different household-based enterprises. The major pest of sampaguita (jasmine) is white fly (Allyrodidae), which leaves tiny pupal cases on the underside of leaves and leaves secretions which act as substrate for sooty mould. The “budborer” (still being scientifically identified) is possibly of greater economic significance. It penetrates the bud at a very young stage and devours the bud from within, remaining hidden until the damage is done. Ninety percent of farmers interviewed, on a pesticide-use survey, mentioned the budborer and 88% mentioned the white fly, as the major pests.
Although farmers indicated a knowledge of the dangers of pesticide use, they regarded regular spraying as practically synonymous with sampaguita farming. The key factor influencing the choice of pesticides was its “effectiveness” in the eyes of the farmer and additional important recommendations from other farmers and pesticide traders. Less than 5% of the sample mentioned low toxicity as an important factor. Some clarification is still needed on pesticide applications, which varied with the season. During the peak season, two-thirds of farmers spray either every day or every two days. In the lean season, one-third spray every two or three days, whereas 40% spray once a week and 17% do not spray at all.

A total of 21 pesticides were being used by sampaguita farmers, consisting of two fungicides and 19 insecticides. The most common, used by 83% of respondents, was methomyl, a highly toxic compound which can be absorbed through the skin. Three pesticides mentioned have already been banned. Ninety percent of respondents said they used protective clothing and 83% said they used masks, though visual assessment has not yet been made. The most commonly reported health effect, of pesticide application, was dizziness, among 17% of the sample, followed by vomiting (13%) and itchiness and headache (both 10%). To understand better likely health risks, pesticide residue assessments were made of flowers at different points along the marketing chain from the field to the garland-sellers. The results indicated important, if not alarmingly high, residues, though the health risks cannot at present be assessed accurately because of lack of guidelines. Lack of available protocols also prevented inclusion of methomyl, the most commonly used pesticide, in the analysis. A number of anomalies evident in the data, such as higher residues amongst vendors compared to flowers in the farm will require further investigation.

In Yaounde IITA, ICLARM and local universities have completed a study and mapping of water contamination levels at different points of the local drainage system. Levels of fecal coliform are high in water and fish in urban lakes, but levels of heavy metals are generally below recommended limits. Preliminary recommendations for removal of urban agriculture from the inland valleys (bas-fonds) as a means to combat the extensive use of contaminated water in this type of agriculture seem premature, given existing understanding of risk and the social implications of such a recommendation. There is no evidence of massive health risks from consumption of cooked food coming from these valleys, though there may be health risks to farming families. There may also be kitchen contamination from bacteria coming from fish. In general, the risks and implications of practicing UPA under these conditions are still not widely understood. They also need to be addressed in the broader context of the urban environment, in which settlements of the poor grow up around contaminated water and without sanitation.

In Kampala, a CIDA funded project entitled Urban Agriculture in Kampala, Uganda - Health Impact Assessment and Options for Improvement began June 12 – 14, 2002, with a Stakeholders’ Meeting and Planning Workshop. The meeting pooled available knowledge on health impacts, both the negative impacts caused by contaminants and the positive effects on health and nutrition of farming activities. Together with the parallel project on Strengthening Urban Agriculture in Kampala, a Participatory Urban Appraisal (PUA) was conducted in five parishes. In addition to livelihoods and agricultural production data, discussions also took place with local groups on health issues and particularly on health risks and hazards perceived in their locality. The results indicate that the poorest groups have inadequate or non-existent access to health care and experience considerable ill-health. Those involved in agriculture perceive a wide range of hazards and it is clear that the notion of “hazards” refers both to phenomena that directly impinge on health, such as wetland farms contaminated with industrial effluent or domestic wastes, or zoonotic diseases associated with pig-raising, as well as phenomena that indirectly affect health, such as poor productivity due to inadequate seeds, or practices that affect the “health” of the environment, such as tree-felling causing erosion. At the same time, groups from a wide spectrum of locations in the city (from the old city center to agriculturally stable peri-urban areas) concur in the positive benefits derived from UPA, especially its contribution to food security, to better nutrition and to improved income. The PUA conducted in the urban center of Kampala included comments about the savings than can be made through subsistence production, freeing cash for other uses.
In depth studies are currently on-going to examine particular issues which emerged from this appraisal, including a new project on “Characterizing and Assessing the benefits and risks of urban and peri-urban livestock production in Kampala city”, led by ILRI.

Another recently initiated health and resources-related project, also, led by ILRI with Urban Harvest and ICRAF participation and strong national involvement is entitled “Management of organic wastes and livestock manures for enhancing agricultural productivity in urban and peri-urban Nairobi”.

In Lima CIP-led research on the development of a weaning food for infants from poor urban families in Lima continued. During 2002 the development of the instant weaning food with sweetpotato base was finalized, complying with all the requirements of the Ministry of Health in terms of proximal analysis, total sugars, reducing sugars, starches, index of gelatinization, acidity, index of peroxides, dietary fiber, linoleic acid, amino grams and complete microbiological analysis.
Consequently acceptability trials were completed with children from 6 months to 2 years in the peasant community of Jicamarca in the Eastern Cone of Lima and in the settlement of Delicias de Villa in the Southern Cone.
A costs-of-production study was made using the small-scale pilot experience to simulate medium-level commercial production of the weaning food. Using production data for the most appropriate sweetpotato varieties for the weaning food, a mean cost of $ 0.34 per ration of 90 g of papilla was obtained.
Furthermore, through an MS Business Administration thesis, a marketing study was conducted of the product. The study assessed competing products in the market and the type of market positioning and brand that would be most effective. The study also assessed the volume of demand for the type of product and the likely selling price, given the competing products.
Finally, a study of the storage characteristics of the weaning food has recently been completed as a thesis topic for the professional qualification of a food industry engineer.