Sustainable Maize Production for Human Health and Biodiversity in Laos
The commercialization of agriculture in the Laos People’s Democratic Republic (PDR) has resulted in an increase in pesticide imports of more than 3,700% over a decade, reaching 2.3 million kilograms in 2019 — a figure that only includes what entered the country legally. Sadly, the intended improvements in food security and farmer income are undermined by pesticide’s negative impacts on human health and biodiversity. Interventions are needed to raise awareness of the problem and to promote sustainable, healthy agricultural production.
Xieng Khouang province and other upland areas of Laos are the home of the country’s ethnic minorities — people who have, until recent decades, lived outside mainstream development efforts. Their traditional practice of mixed cropping through labor-intensive shifting agriculture has become unsustainable due to increasing pressures on the land. With high levels of poverty and malnutrition present, it made sense for the government to encourage sedentary agriculture, focusing on commercial crops with the aim of improving incomes and thereby ensuring food security. This began in the mid-2000s and accelerated over the next decade, with maize for animal feeds becoming an export crop.
High and dangerous pesticide use
Maize production is only maintained at high levels if the land is fully cleared prior to sowing, weeds are regularly removed, fertilizer is applied and insect pests and diseases are kept in check. The main herbicides used include paraquat, glyphosate, atrazine and 2,4-D, all of which are controversial and most of which are banned from use in high-income countries. Paraquat, for example, is banned in the European Union and Switzerland and is classed as a restricted use pesticide in the United States — meaning that it should only be used by persons who have received training and wear protective clothing. The use of paraquat is, in fact, banned in Laos, but this information is generally disregarded or unknown and imports continue. Farmers often cannot read the instructions on pesticides, tend to spray far more than the recommended amounts and do so wearing no or inadequate protection. In many parts of Xieng Khouang province, almost every household has a sprayer machine.
This is not to imply, however, that there is complete unawareness of the health risks or of the overall unsustainability of the system. People are simply caught in a vicious cycle of dependence on income from maize sales, declining soil fertility, the need to clear more land to maintain production and, hence, the necessity to apply herbicides. It is invariably the most disadvantaged individuals who do this work. As one village head put it, he now pays somebody “who is not afraid to die” to do the spraying for him. Beyond the slow deterioration to health caused by contact and accidental inhalation, there is a real risk of more immediate death. Local hospitals have reported various cases of fatal poisoning due to pesticides, both as accidents and suicides.
A wealth of knowledge in sustainable agriculture
The irony of the current situation is that alternative means of crop production are known. Shifting agriculture, though generally considered quite a “primitive” form of cultivation, is sustainable if the rotation period is long enough to allow for soil recovery. In its traditional form, it encompassed a multilayered system of root, ground-hugging, mid-level and bush or tree crops with differing demands for light and soil depth. Pest attack by insects, nematodes and bacterial or viral diseases was limited by the differing susceptibility of the diverse crop species and the practice of rotation. The downsides of such systems are that they are very physically demanding and generally only meet subsistence needs.
The Laos Upland Rural Advisory Service (LURAS) project has been operational since 2016, working with the agricultural authorities of Xieng Khouang province to provide technical assistance through Helvetas and the Dutch organization, SNV. It supports on-farm research, the dissemination of agricultural information and farmer-to-farmer exchange, including through social media. It also seeks to inform policy debates and develop the capacity of local advisors.
Evidence of pesticide pollution
Facts must be collected, analyzed and presented if a policy is to be questioned or changed. LURAS has been working with the different authorities in charge of rural development and provincial health to determine levels of pesticide in water supplies and in human blood. In a survey of 103 farmers, it found that over 90% reported at least one symptom of acute exposure following pesticide application, including headache, dizziness, rash, nausea, vomiting and difficulty breathing. Meanwhile, blood samples from the public show that, on average, about one-third of individuals sampled had “unacceptable” residue levels, well above those considered dangerous to one’s health by the World Health Organization. Levels for school children are a particular cause for concern. LURAS has publicized this information and facilitated policy dialogue; this has contributed to a new government strategy to promote “Green and Sustainable Agriculture,” as well as new projects to address the issue of food safety.
Integrated pest management against the fall armyworm
The widespread spraying of chemical pesticides tends to destroy all insects, including beneficial ones, such as honeybees, other crop pollinators, insect pest predators and parasitoids. In 2019, the arrival in Laos of the fall armyworm, Spodoptera frugiperda, provided an opportunity to demonstrate an alternative means of control to spraying pesticide. This pest is well known for its ability to spread rapidly with devastating consequences, but its life cycle and periods of vulnerability are also well known. The project was, therefore, able to prepare extension materials in the Lao language quickly and to disseminate them via social media. Farmers could react immediately on spotting any outbreak in their fields.
Through Participatory Action Research (PAR), farmers could also exchange and compare the effectiveness of different control methods, such as manual caterpillar removal, rearing chickens in maize fields, the introduction of natural predators (such as stink bugs, Eocanthecona furcellata) and the use of botanical extracts (such as Guduchi, Tinospora cordifolia). Fall armyworm is notorious for becoming resistant to pesticides, so it is especially urgent to identify and promote different control methods for this pest. The project was also proactive in assisting farmers to explore alternative crops to maize and integrated pest management in these crops.
Effective agricultural advisory services must be context-specific — built on an understanding of local social, economic and political, as well as agroecological, conditions. It is this that shapes the work of LURAS and on which the sustainability of project interventions depends. When it comes to the control of a pest like fall armyworm, farmers are discovering that local plants and insects may provide more effective, safer and less costly control than imported chemicals.
This article was authored by Souvanthong Namvong and Pheophanh Soysouvanh from the Department of Extension, Ministry of Agriculture and Forestry, Vientiane; Ianlang Phanthanivong from the Provincial Office for Xieng Khouang, Ministry of Agriculture and Forestry; Sopavanh Rassapong, knowledge management consultant for the LURAS project; and Andrew Bartlett and Jane Carter from Helvetas.