U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Soil, Water & Air Resources Research: Ames, IA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    CRIS ProjectsSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area Ames, Iowa National Laboratory for Agriculture and The Environment Soil, Water & Air Resources Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Prueger, Johnitem
                                            Alfieri, Josephitem
                                            Gish, Timothyitem
                                            Kustas, William

                                                         - *Bill*item
                                            Daughtry, Craigitem
                                            Hatfield, Jerryitem
                                            McKee, Lynn
  Submitted to: Water, Air, and Soil Pollution
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 1/10/2017
                                    Publication  Date: 2/2/2017
                                    Citation: Prueger, J.H., Alfieri, J.G., Gish, T.J., Kustas, W.P., Daughtry, C.S., Hatfield, J.L., Mckee, L.G. 2017. Multi-year measurements of field-scale metolachlor volatilization. Water, Air, and Soil Pollution. 228. Article 84. https://doi.org/10.1007/s11270-017-3258-z.DOI: https://doi.org/10.1007/s11270-017-3258-z                                                              
                                Interpretive Summary: Pesticide volatilization is a process where pesticides move from a liquid phase on soil or vegetation surfaces to a chemical gas phase that is then released to the atmosphere. The amount of pesticides applied annually in US farming operations is well over 100 million tons and yet the amount of pesticide volatilization to the atmosphere is not well known. In this study we measured concentrations of two commonly used herbicides (metolachlor and atrazine) for corn and soybean production for 13 consecutive years. Using meteorological measured parameters measured at the same time we computed the volatilization losses across all 13 years. Our results showedthat volatilization losses were significantly greater than previously believed. Our results also confirmed that volatilization losses for metolachlor and atrazine were greater than losses from leaching and runoff. Additionally the volatilization losses were closely correlated to the amount of soil water content which varies across years as a function of local meteorological conditions. This information is of value to pesticide compaies and regulatory agencies in improving their understanding of volatilization losses.
                                Technical Abstract: Volatilization is a critical pathway for herbicide loss from agricultural fields, and subsequently deposited downwind from the edge of the field. To better understand the volatilization process, field-scale turbulent volatilization fluxes of metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide) and atrazine (6-chloro-N-ethyl-N’-(1-methylethyl)-1,3,5-triazine-2,4-diamine) were quantified for 13 consecutive years using a combination of herbicide concentration profiles and eddy diffusivities derived from turbulent fluxes of heat and water vapor. Site location, type of herbicides, and agricultural management practices remained unchanged during this study in order to evaluate the effect of soil moisture on volatilization of metolachlor and atrazine. Twenty gravimetric surface soil moisture samples (0-5 cm) were collected immediately after herbicide application and then at 0430 h each morning to determine the impact of surface moisture on herbicide volatilization. Five days after application, cumulative herbicide volatilization ranged from 5% to 63% of that applied for metolachlor and from 2 to 11% of that applied for atrazine. For both atrazine and metolachlor, volatilization remained an important loss process more than 5 days after application, if the soil surface was moist.  Conversely, if the soil surface was dry, negligible volatilization occurred beyond 5 days. Furthermore, the total amount of metolachlor volatilized into the atmosphere increased exponentially with surface soil water content during application (r2 = 0.78). However, volatilization of atrazine and initial surface soil moisture showed more variation over the different years due to the lower volatility of atrazine compared to metolachlor. Atrazine and metolachlor volatility were found to a large extent to be governed by surface soil moisture.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov