Source: UNIVERSITY OF FLORIDA submitted to NRP
FATE AND TRANSPORT OF PESTICIDES IN AGRICULTURAL SOILS OF FLORIDA
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0218158
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Apr 1, 2009
Project End Date
Mar 31, 2014
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF FLORIDA
G022 MCCARTY HALL
GAINESVILLE,FL 32611
Performing Department
Soil and Water Sciences
Non Technical Summary
The reasearch will provide data on pesticide fate and transport in Florida agricultural soils that are not currently available. The understanding of leaching of pesticides below the root-zone will guide farmers to apply pesticides amounts that are needed within the root-zone. Plant uptake data for some pesticides will be used to understand the efficacy of pesticides in plant parts. Modeling pesticide leaching will provide data to simulate what might happen to pesticides applied to crops in the state of Florida.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1020110200030%
1020110201020%
1020110205010%
1330999205010%
1331499201010%
2065220208010%
2115210200010%
Knowledge Area
206 - Basic Plant Biology; 133 - Pollution Prevention and Mitigation; 102 - Soil, Plant, Water, Nutrient Relationships; 211 - Insects, Mites, and Other Arthropods Affecting Plants;

Subject Of Investigation
1499 - Vegetables, general/other; 0110 - Soil; 0999 - Citrus, general/other; 5210 - Fertilizers; 5220 - Pesticides;

Field Of Science
2010 - Physics; 2050 - Hydrology; 2080 - Mathematics and computer sciences; 2000 - Chemistry;
Goals / Objectives
The project goals include the understanding of the processes that affect the fate and transport of pesticides in agricultural soils of Florida in order to reduce the potential for pesticides to pollute surfce and ground water resources. The processes to be studied will include sorption, transformation, and movement of pesticides within and below the root-zone and also uptake by some crops. The data will be modeled with process oriented models such that the obtained research data can be transfered to other locations where the data were not collected.The main objectives of the research project are listed below. 1)Collect soil samples from Florida that have contrasting organic matter content in the five dominant soil orders (Spodosols, Entisols, Histosols, Ultisols, and Alfisols). 2)Separate soil samples into textural classes (sand, silt, and clay) and soil aggregates. 3)Correctly measure organic carbon (OC) of whole soils that will be used to calculate KOC and measure OC in soil separates. Measure carbon sequestration in soil aggregates. 4)Characterize soil organic matter functionality using CP-MAS 13C NMR spectroscopy. 5)Calculate molecular surface areas of probe pesticides; total (TSA), polar (PSA) and hydrocarbonaceous (HSA). 6)Measure sorption coefficients of selected weakly hydrophobic organic pesticides (WHOPs) in aqueous systems. WHOPs have KOC values less than 1000. 7)For selected strongly hydrophobic organic pesticides (SHOPs), determine the extent of sorption on container walls (Teflon centrifuge tubes) and HPLC vials in mixed solvents. SHOPs have KOC values greater than 10,000. Select a range of mixed solvents in which sorption of SHOPs on container walls is eliminated. Then measure sorption coefficients of SHOPs in soils using mixed solvents and calculate KOC with aid of the Solvophobic model. 8)Study effect of soil aging on bioavailability of WHOPs and SHOCs by measuring the effect of redox potentials on dissolved organic matter (DOM) and natural organic matter (NOM). 9)Study sorption and desorption of WHOPs and SHOPs on aged soils. 10)Measure degradation rate coefficients of selected pesticides in soils. 11)Study the transport of imidacloprid in soils and citrus plants in field and in growth chambers during irrigation. 12)Model imidacloprid transport in the field using the model LEACHM.
Project Methods
The soil series predominantly used for crop production will be sampled from the 5 Soil Orders of Florida. The disturbed soil samples will be used to determine soil OC (Walkley and Black, 1934), CEC, pH, and soil texture using standard methods. The undisturbed soil cores will be used to measure soil moisture release curves and hydraulic functions. Some of the parameters are needed to run the model LEACHMP. The particle size separates will be: sand (< 20-5 μm), fine silt (< 5-2 μm), and clay (< 1,000) and will be normalized with organic carbon (OC) content of each soil-material. For the sorption isotherms, 12C-compounds or 14C-compounds will be used depending on commercial availability. Equilibrium solution concentration will be analyzed by either HPLC with UV detection, by liquid scintillation counting, or by GC with appropriate detectors. The amount of chemical adsorbed will be determined by difference from the initial solution concentration. For strongly hydrophobic chemicals (Koc > 10,000) the co-solvency model (Nkedi-Kizza et al., 1985) will be used to determine sorption isotherms in mixed solvents (methanol-water). Pesticide/imidacloprid transport/movement in soils cropped with citrus will be conducted at Immokalee Research and Education Center in collaboration with Dr. K. Morgan. Applied imidacloprid will be monitored in soil samples taken as a function of soil depth and time. The soil samples will be extracted with appropriate solvents and analyzed with HPLC-UV, using a mobile phase (70:30, water: acetonitrile), C-18 column, at a flow rate of 1 ml/min and detected at a wavelength of 277 nm (Kamble Saran 2005). Leaf samples will be extracted with appropriate solvents to analyze for imidacloprid translocated into citrus leaves. The leaching data of pesticides/imidacloprid will be simulated with the model LEACHMP.

Progress 04/01/09 to 03/31/14

Outputs
Target Audience: 1. Science community at national meetings, for 4 years 2. Seminars at UF-campus and also at UF-Research centers during meetings with farmers, for 4 years 3. Publications in refreed science journals. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? 1. One PhD student and one MS student have graduated. 2. 5 undergraduate students worked on the project in the lab and in the field. How have the results been disseminated to communities of interest? 1. At annual science meetings for 4 years. 2. At seminars on UF campus and at UF-Rsearch Centers interacting with farmers 3. Through thesis/dissertation. What do you plan to do during the next reporting period to accomplish the goals? The project has ended.

Impacts
What was accomplished under these goals? 1. Soil sorption kinetics of Imidacloprid in Immokalee fine sand showed the process to be fast achieving equilibrium in less that 24 hours. 2). The sorption coefficient of Imidacloprid (IMD) in soil was calculated normalised to soil OC as [KOC = 200]. IMD is weakly sorbed in soil.3). IMD half life was about 1 year in the three horizons of Immokalee Fine Sand imply IMD is persisitent in the soil environment. 4. Extraction of IMD from leaf tissue by a bullet blender and analysis of extracts by HPLC/MS/MS weree developed in our project. The procedure is the only one available in the literature. 5). IMD was easly taken up by citrus starting to appear in the leaf two weeks after application to the soil and effectively controlled the psyllids (ACP). 6). Bromide as a tracer for water movement was out of the root-zone (0-45 cm) in 9 days. However, IMD was stiil in the rootzone after 21 days. 7). Less that 4% of IMD was leached out of the root-zone, the rest must have been taken up by citrus plants. 8). Psyllid counts data revealed that a minimum concentration in the leaf can considerably reduce ACP populations. 9. One-Site-Nonequilibrium model was found adequate to describe IMD sorption kinetics in batch and during leaching under saturated water flow. 10). The field leaching data of IMD was not simulated with HYDRUS because of uncertainity in IMD plant uptake. 11). IMD metabolites were not included in the study because we were not able to get standards commercially or otherwise. 12). NMR spectra data revealed that Carbonatic-Marl soils from South Florida resemble algae but the Organic soils did not. The sorption of IMD in Carbonatic-Marl soils was predominantly due to Phenolic-Aromatic-C but for the Organic soils it was Aromatic-C. For the sorption of atrazine, Aromatic-C was predominant for Carbonatic-Marl soils and Aromatic-C+Alkyl-C groups predominantly adsorbed atrazine. 14). Imidacloprid did not sorb on container walls.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Jorge A.Leiva, Peter Nkedi-Kizza, Kelly Morgan, Jawwad A. Qureshi.2013. Imidacloprid Fate and Transport in Florida Flatwoods Soils during Control of the Asian Citrus Psyllid. SSSA-Soil and Environmental Quality, Abstract, Tampa, Florida, Meetings.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Jorge A.Leiva, Peter Nkedi-Kizza, Kelly Morgan, Jawwad A. Qureshi, and Thomas A. Obreza. 2013. Imidacloprid Fate and Transport in Florida Flatwoods Soils during Control of the Asian Citrus Psyllid. Soil and Water Science department Forum,fall, 2013, Gainesville Florida
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Jorge A. Leiva, Peter Nkedi-Kizza, Kelly Morgan, Davie Kadyampakeni, Evelyn V. Fletcher, Augustine Muwamba. 2013. Imidacloprid Miscible Displacement in Soil Columns of Immokalee Fine Sand during Saturated Flow. SSSA-Soil Physics-Lightning Oral Presentation. Abstract, Tampa, Florida Meetings.
  • Type: Journal Articles Status: Published Year Published: 2011 Citation: Wasswa, John, Bernard T. Kiremire, Peter Nkedi-Kizza, Jolocam Mbabazi, Patrick Ssebugere . 2011. Organochlorine pesticides residues in sediments from the Uganda side of Lake Victoria. Chemosphere 82:130-136.
  • Type: Journal Articles Status: Published Year Published: 2011 Citation: Ouyang, Ying, Jia-En Zhang, Li Hua Cui, Peter Nkedi-Kizza. 2011. Simulating Transport and Fate of Herbicide Trifluralin in a Soil. Journal of Sustainable Watershed Science and management,1(2)53-60
  • Type: Journal Articles Status: Accepted Year Published: 2012 Citation: Kasozi, G. N, P. Nkedi-Kizza, Y. Li, A. R. Zimmerman. 2012. Sorption of atrazine and ametryn by carbonatic and noncarbonatic soils of varied origin. J. Environmental Pollution 169 (2012)12-19
  • Type: Theses/Dissertations Status: Published Year Published: 2014 Citation: Evelyn Fletcher. 2014. Imidacloprid Fate and transport in Immokalee Fine Sand During Control of the Asian Citrus Psyllid. MS thesis, University of Florida.
  • Type: Theses/Dissertations Status: Published Year Published: 2014 Citation: Jorge A. Leiva. Imidacloprid Fate and Transport in Florida Flatwoods Soils and Plants During Control of the Asian Citrus Psyllid. PhD dissertation, University of Florida.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Jorge A. Leiva, Peter Nkedi-Kizza1, Kelly Morgan, Jawwad A. Qureshi. Imidacloprid Soil-Drench Application in Young Citrus Trees of Florida: Sorption, Degradation, and Systemic Effects On Asian Citrus Psyllid. Poster 357-2, ASA,CSSA,SSSA, Annual, Meeting, Cincinnati, Ohio, October 21-24, 2012.


Progress 10/01/12 to 09/30/13

Outputs
Target Audience: 1. Scientists who are members of the Soil Science Society of America at annual meeting, fall, 2013 in Tampa, Florida. 2. Scientists who attended the Soil and Water Science department, research forum at the university of Florida in september, 2013. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? One PhD student and one MS student completed field and laboratory studies on imidacloprid. They both started writing dissertation, and thesis, respectively. How have the results been disseminated to communities of interest? Through national science meetings and UF campus seminars. What do you plan to do during the next reporting period to accomplish the goals? Write the final report.

Impacts
What was accomplished under these goals? Modeling of imidacloprid leaching through water saturated soil columns of A, E, and Bh soil horizons of Immokalee Fine Sand, was completed. The data were described by the One Site Nonequilibrium (OSNE) model.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Jorge A.Leiva, Peter Nkedi-Kizza, Kelly Morgan, Jawwad A. Qureshi, and Thomas A. Obreza. 2013. Imidacloprid Fate and Transport in Florida Flatwoods Soils during Control of the Asian Citrus Psyllid. Soil and Water Science department Forum,fall, 2013, Gainesville Florida.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Jorge A. Leiva, Peter Nkedi-Kizza, Kelly Morgan, Davie Kadyampakeni, Evelyn V. Fletcher, Augustine Muwamba. 2013. Imidacloprid Miscible Displacement in Soil Columns of Immokalee Fine Sand during Saturated Flow. SSSA-Soil Physics-Lightning Oral Presentation. Abstract, Tampa, Florida Meetings.


Progress 10/01/11 to 09/30/12

Outputs
Target Audience: Members of the Soil Science Society of America during annual meetings, fall, 2011. Members of the Soil and Water Science department at the University of Florida during the Forum in September 2012. Changes/Problems: Try to analyze Imidacloprid in plant tissue using HPLC/MS/MS rather than HPLC/UV because of problems with clean up proceedures. What opportunities for training and professional development has the project provided? One PhD student and one MS student continued with their research on imidacloprid at Immokalee Research and Educational Center. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Summary of lab and field data on Imidacloprid fate and tarnsport in soil. Develop an extraction procedure for Imidacloprid from plant leaf tissue. Analyze Imidacloprid in plant tissue and correlate with soil concentration.

Impacts
What was accomplished under these goals? Characterization of soil organic matter by CP-MAS 13C NMR spectroscopy was completed for carbonatic, organic, oxisols and spodosols soils. Sorption of SHOCs and SHOPs on container walls was completed. Sorption, transport, and degradation of imidacloprid in soils in the lab was completed. Elimination of sorption of SHOCs and SHOPs on container walls using mixed solvents was ompleted.

Publications

  • Type: Journal Articles Status: Published Year Published: 2011 Citation: Wasswa, John, Bernard T. Kiremire, Peter Nkedi-Kizza, Jolocam Mbabazi, Patrick Ssebugere . 2011. Organochlorine pesticides residues in sediments from the Uganda side of Lake Victoria. Chemosphere 82:130-136.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Ouyang, Ying, Jia-En Zhang, Li Hua Cui, Peter Nkedi-Kizza. 2011. Simulating Transport and Fate of Herbicide Trifluralin in a Soil. Journal of Sustainable Watershed Science and management,1(2)53-60
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Kasozi, G. N, P. Nkedi-Kizza, Y. Li, A. R. Zimmerman. 2012. Sorption of atrazine and ametryn by carbonatic and non-carbonatic soils of varied origin. J. Environmental Pollution 169 (2012)12-19


Progress 10/01/10 to 09/30/11

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? One PhD student and one MS student was recruited to work on the project. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Continue to study imidacloprid leaching and uptake by the citrus trees and control of citrus greening.

Impacts
What was accomplished under these goals? 1. Data from sorption experiments of Imidacloprid in eleven carbonatic soils and 5 organic soils indicated that the pesticide adsorb much less in carbonatic soils compared to non-carbonatic soils. Carbonatic soils contain more than 40% CaCO3. The KOC values for Imidacloprid were about a third of the literature KOC values reported for non-carbonatic soils. To understand the fundamental differences between Carbonatic soils and other soils, stable isotopes and 13C CP-MAS NMR were used to characterize soil organic matter. The differences were in the aromatic carbon chemical shifts. Carbonatic soils displayed lower aromaticity and the sorption of Imidacloprid was predominantly in the Aromatic-C-Phenolic functional groups. However, a strong relationship was found between Imidacloprid sorption coefficient KOC and aromatic-C functional groups of organic matter in organic soil (Histosols). This implies that the aromatic carbon controls the sorption of neutral hydrophobic organic chemicals. 2. Sorption and degradation are major processes that influence the fate of pesticides in the environment. This study was designed to understand how Imidacloprid used to control citrus greening adsorbs and transforms in Immokalee fine sand used for citrus production in Florida. A field study and lab experiments show so far that Imidacloprid is weakly sorbed and persists in the environment for a long time. The half life is about a year, but leaching is very rapid in the field not lasting for more than 6 weeks in the root zone once applied. It is effective in controlling citrus greening but because of leaching it does not reside in the root-zone longer than 6 weeks.

Publications


    Progress 10/01/09 to 09/30/10

    Outputs
    Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? 3 PhD students and 1 MS student. How have the results been disseminated to communities of interest? Through journal articles and conferences. What do you plan to do during the next reporting period to accomplish the goals? Sorption of SHOCs and initiate imidacloprid lab and field studies.

    Impacts
    What was accomplished under these goals? 1. Data from sorption experiments of pesticides (atrazine and diuron, ametryne, DDT, imidacloprid, and dieldrin) in eleven carbonatic soils and 5 organic soils indicated that the pesticides adsorb much less in carbonatic soils compared to non-carbonatic soils. Carbonatic soils contain more than 40% CaCO3. The KOC values for pesticides were about a third of the literature KOC values reported for non-carbonatic soils. Use of literature KOC values in transport model will most likely underestimate the mobility of neutral organic pesticides in carbonatic soils. 2. Several pesticides applied to Carbonatic soils have been reported in surface and ground water of South Florida and Puerto Rico. Although a lot of research has been done on characterizing the sorption of organic pesticides by non-Carbonatic soils, a literature search indicates lack of such data for Carbonatic soils. The conversion factors from organic carbon to organic matter were 1.74, 1.48, and 1.47 for Carbonatic, Histosols and Spodosols, respectively. The differences were partly due (to weight loss in Histosols between temperatures of 110-200 oC, a loss erroneously included in the weight-loss-on-ignition determination) and partly due to differences in the source and origin of organic matter. The sorption coefficient normalized with organic carbon content (KOC) for the non-Carbonatic soils were about 3 times higher than of Carbonatic soils for atrazine, ametryn, carbaryl, and diuron. The use of literature pesticide sorption data in transport models is therefore likely to underestimate the potential for pesticides to pollute groundwater in South Florida and Puerto Rico. Degradation of diuron, atrazine, carbaryl, and ametryn was not different between Carbonatic and non-Carbonatic soils and was not influenced by sorption. To understand the fundamental differences between Carbonatic soils and other soils, stable isotopes and 13C CP-MAS NMR were used to characterize the soil organic matter. The differences were in the aromatic carbon chemical shifts. Carbonatic soils displayed lower aromaticity. A strong relationship was found between aromatic C/alkyl C and Koc. This implies that the aromatic carbon controls the sorption of neutral hydrophobic organic chemicals.

    Publications

    • Type: Journal Articles Status: Published Year Published: 2010 Citation: Wasswa, J., Nkedi-Kizza, P., and Kiremire, B.T. 2010. Characterization of Sorption of Endosulfan Isomers and Chlorpyrifos on Container Walls Using Mixed Solvent Systems. J. Agric. Food Chem. 58:7902-7909. Kasozi N. Gabriel, Zimmerman, R. Andrew, Nkedi-Kizza, P, and Gao Bin. 2010. Catechol and Humic Acid Sorption onto a Range of Laboratory-Produced Black Carbon (Biochars). Environ. Sci. Technol. 44: 6189-6194


    Progress 10/01/08 to 09/30/09

    Outputs
    OUTPUTS: The adsorption and degradation of the pesticide diuron in carbonatic and non-carbonatic soils were investigated to better understand the fate and transport of diuron in the environment. Batch adsorption experiments yielded isotherms that were well-described by the linear model. Adsorption coefficients normalized to soil organic carbon content (Koc) were lowest for carbonatic soils, averaging 265, 558, 973 and 2090 for carbonatic soils, Histosols, Oxisols, and Spodosols, respectively. In addition, marl-carbonatic soils, had much lower Koc values (197) than non-marl carbonatic soils. Diuron degradation data fit a first order reaction kinetics model, yielding half-lives in soils ranging from 40 to 267 days. There was no significant difference between the average diuron degradation rate coefficients of each of the soil groups studied. Given the low adsorption capacity of carbonatic soils, it may be advisable to lower herbicide application rates in agricultural regions with carbonatic soils such as South Florida in order to protect aquatic ecosystems and water quality. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

    Impacts
    Marl-carbonatic soils adsorbed pesticides less compared to the outcrop carbonatic soils. The cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance (CP-MAS 13-C NMR) data indicate that Algae is the primary producer of OM in the marl soils. This implied that its contribution to OC aromaticity that predomonantly controls the sorption of organic pesticides is limited. The lack of aromatic-C in carbonatic soils OM probably leads to the low sorption capacities exhibited by carbonatic soils from South Florida and Puerto Rico. The linear relationship obtained by normalizing the sorption coefficients with the soil OC content indicates that OC controls the adsorption of organic pesticides in carbonatic soils. However, the data variability across different soil types suggest that functionality of OM is an important criteria for sorption.

    Publications

    • Kasozi,G., P. Nkedi-Kizza, S. Sampson-Birikor, and A. Zimmerman. 2010. Characterization of Adsorption and degradation of Diuron in Carbonatic and Noncarbonatic Soils. J.Agric.Food Chem.58:1055-1061.