2006 Annual Report
1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter?
Sustaining legal crops as economically viable alternatives to illicit drug crops is inevitably a challenge, and especially so in parts of tropical Latin America. Fostering such alternatives is in the interest of both the U.S. and the producer countries, since the societal cost of drug abuse is huge. Crop pest control is essential to achieving agricultural success, but wide use of pesticides has led to detectable pesticide residues in commodities and, sometimes, high amounts in soil or water near the application sites. Despite this, documentation of pesticide use for protecting tropical perennial or other crops in Latin America, as well as their environmental residue levels, is not easily found, particularly where such commodities are grown to replace illicit coca. The researchable problems are therefore to document pesticide use in the region(s) of focus, estimate expected exposure and perhaps risk from the products used, and develop a research program that will quantify pesticide environmental behavior, as well as potential uptake into crop plants.
The major approaches to address these problems will be: A1. Assess current pesticide use for selected tropical crops (particularly perennials banana, cacao, and coffee) through existing data bases and knowledgeable sources; A2. Assess any reported information about health effects or environmental contamination from uses of these products, primarily in the regions of focus; A3. Conduct a preliminary risk assessment (exposure) of selected pesticides; B1. Conduct field and supporting laboratory studies to determine and model pesticide transport and dissipation within the relevant plant, soil, water, and (if needed) atmospheric components of the targeted tropical agroecosystems; and B2. Provide guidance about potential pesticide exposure levels as a function of the pesticide chemistry, application methods, crop management, soils, and meteorological factors.
This research contributes to National Program 304 Crop Protection and Quarantine and NP 303 Plant Diseases. It is linked with Component VIII (Chemical Control of Weeds), but is related as well to other types of crop pest control. Elucidating environmental safety aspects of crop protection supports Strategic Plans 220.127.116.11 (Weed Control), 18.104.22.168 (Soil-Surface Interactions), and 22.214.171.124 (Efficacy and Residue Data—Minor Use). The project also relates indirectly to NP 201 Water Quality and Management and NP 202 Soil Resource Assessment, in environmental and economic risk evaluation.
2.List by year the currently approved milestones (indicators of research progress)
Year 1 (2006)
• Conduct preliminary survey on pesticide use, fate, and impacts for priority areas.
• Prioritize chemicals & crops for Objective 2 field/lab research, based on information analysis.
• Assess, select, and characterize (soil properties) field sites in Peru for long-term studies on pesticide fate.
Year 2 (2007)
• Complete database on pesticide use and related fate/impacts for priority areas.
• Prepare final report related to assessment of pesticide use and known impacts, for priority selected crops and region(s).
• Complete initial risk assessment for selected pesticide use in targeted cropping systems and region(s).
• Select, test, and refine methods for analyzing primary pesticides [chosen based on Objective 1 research] and their major metabolites in tropical soil and water samples.
• Conduct Phase I limited monitoring studies on pesticide residues in soil and water near the priority field experimental sites.
• Plan and initiate fallow plot field dissipation experiment on priority pesticides.
• Identify and map field site for runoff study as related to project objectives.
Year 3 (2008)
• Complete Phase II monitoring of pesticide residues in environmental samples in the region of the priority field experiment(s).
• Complete installation of flume(s) and monitoring wells.
• Characterize adsorption and leaching of pesticides used in field experiments, through laboratory studies.
• Complete field leaching and persistence determination of first-priority treatments, on fallow plot sites.
Year 4 (2009)
• Complete final report of pesticide environmental monitoring in the region of primary field studies.
• Complete soil and water sampling and analyses to quantify pesticide loss from field plots.
• Complete field testing of pesticide residues in crop commodities and in soil and water near the treated crops.
Year 5 (2010)
• Complete environmental risk assessments based on the project’s field and laboratory studies, in comparison with other published data and the use of pesticide fate models, to make recommendations about pesticide use and safety for targeted alternative crops.
4a.List the single most significant research accomplishment during FY 2006.
Establishment of Field Plots in Peru
This accomplishment aligns with Component VIII (Chemical Control of Weeds) of the National Program 304 Crops Protection and Quarantine and NP 303 Plant Diseases. Field plot experiments were established at two sites in Peru, applying five major pesticides used by farmers in the region for cacao, banana, rice, and other crops. One site on acidic soil was intercropped with banana and young cacao; the second, alkaline-soil site was fallow. First findings showed soil persistence in the order tebuconazole (fungicide) = atrazine (herbicide) > butachlor (herbicide) > chlorpyrifos (insecticide) >> methamidophos (insecticide). Higher soil pH may slightly prolong persistence of butachlor and chlorpyrifos.
4b.List other significant research accomplishment(s), if any.
Pesticide Inventory and Initial Environmental Assessments:
This accomplishment aligns with Component VIII (Chemical Control of Weeds) of the National Program 304 Crops Protection and Quarantine and NP 303 Plant Diseases. A survey of pesticides and other agrochemicals was conducted in San Martin Department, Peru. One farmer had an inventory of at least 33 separate products. Environmental monitoring of a stream at the Peru experiment site showed no trace of contamination in the stream (arising from a forested watershed with small subsistence farm fields) and normal nitrate levels. The nitrate findings are interesting since they may show high attenuation of nitrate in water that may have traveled from a poultry production area above the forested watershed. Monitoring of three rice paddies in San Martin Department showed low levels of methamidophos in two fields. Methamidophos is widely-used for pest control in coca and numerous legal alternative crops; it is relatively toxic. A large number of piezometers and water sampling tubes were installed at the two Peru sites in October-November 2005 and data have been collected for mapping groundwater flow pathways. This will be used for additional, more extensive and long-term environmental research at the sites. Coca eradication effectiveness and production trends in Colombia were evaluated for nearly 44,000 hectares sprayed with glyphosate herbicide in the period October 2005-February 2006. The study has major implications for assessing program effectiveness, adjustment of claimed coca acreage controlled, expected trends in continued coca production, deforestation as a consequence of illicit coca production, and the potential for aerial herbicide spraying to impact surface water or legal crops grown near coca.
4c.List significant activities that support special target populations.
5.Describe the major accomplishments to date and their predicted or actual impact.
Pesticide residues can contaminate soils, water and food products and pose serious health risks. Unfortunately, little is known about pesticide fates in tropical regions of the world. The results of this project have demonstrated environmental persistence of five major pesticides used in the studied tropical Peruvian region. Confirmation through additional, more detailed testing, will show for the first time the fate of these and other pesticide products in this tropical environment. This information will be used by scientists, environmentalists and public health officials to develop environmental assessments and to risk management protocols for tropical agricultural regions NP304, component 8.
6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
None as yet.
7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
Kung, K., Kladivko, E., Helling, C.S., Gish, T.J., Steenhuis, T.S., Jaynes, D.B. 2006. Quantifying pore size spectrum of macropore-type preferential pathways under transient flow. Vadose Zone Journal. 5:978-989.