Environmental Factors Affecting the Movement of Atrazine, Propachlor, and Diazinon in Ida Silt Loam William Frederick Ritter Iowa State University
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Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1971 Environmental factors affecting the movement of atrazine, propachlor, and diazinon in Ida silt loam William Frederick Ritter Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Agriculture Commons, and the Bioresource and Agricultural Engineering Commons Recommended Citation Ritter, William Frederick, "Environmental factors affecting the movement of atrazine, propachlor, and diazinon in Ida silt loam " (1971). Retrospective Theses and Dissertations. 4577. https://lib.dr.iastate.edu/rtd/4577 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. 72-12,588 RITTERj William Frederick, 1942- ENVIRONMENTAL FACTORS AFFECTING THE MOVEMENT OF ATRAZINE, PROPACHLOR, AND DIAZINON IN IDA SILT LOAM. Iowa State University, Ph.D., 1971 Engineering, agricultural ! University Microfilms, A XEROX Company, Ann Arbor. Michigan Environmental factors affecting the movement of atrazlne, propachlor, and diazlnon in Ida silt loam by William Frederick Ritter A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subjects: Agricultural Engineering Sanitary Engineering (Civil Engineering) Approved: Signature was redacted for privacy. Signature was redacted for privacy. For the Major Depértments Signature was redacted for privacy. For(the pgaduate College Iowa State University Ames, Iowa 1971 PLEASE NOTE: Some pages have indistinct print. Filmed as received. UNIVERSITY MICROFILMS. ii TABLE OF CONTENTS Page I. INTRODUCTION 1 II. OBJECTIVES 3 III. LITERATURE REVIEW 4 A. Adsorption of Pesticides 6 B. Pesticide Movement in Soils > 9 C. Photochemical Degradation 13 D. Microbial Degradation 16 E. Chemical Degradation 18 F. Plant Uptake and Translocation 21 G. Volatilization 22 H. Pesticides in Water and Sediment 25 I. Pesticide Analysis 29 1. Extraction of pesticides 29 2. Sample cleanup 31 3. Detection of pesticides 32 J. Summary 34 IV. ANALYTICAL METHODS 38 A. Atrazine 38 1. Extraction of atrazine from soil, water, and sediment samples 38 2. Ultraviolet method for atrazine analysis 41 3. Extraction tests for soil and water samples 44 B. Propachlor 47 1. Extraction methods for soil, water, and sediment sangles 47 2. Detection by gas chromatography 50 3. Extraction tests for soil and water samples 51 iii TABLE OF CONTENTS (continued) Page C. Diazinon 35 1. Extraction methods for soil, water, and sediment samples 35 2. Detection by gas chromatography 39 3. Extraction tests for soil and water samples 60 V. FIELD EXPERIMENT 64 A. Description of the Experiment 64 B. Collection of Water, Sediment, and Soil Samples 69 C. Water and Sediment Losses 74 D. Pesticides in Runoff Water and Sediment 81 1. Âtrazine 81 2. Propachlor 86 3. Diazinon 87 E. Pesticide Movement and Degradation in the Soil Profile 89 1. Atrazine 89 2. Propachlor 103 3. Diazinon 108 VI. LABORATORY EXPERIMENT 111 A. Theory of Pesticide Diffusion in Soils 111 B. Description of the Experiment 114 C. Diffusion Results and Discussion 120 1. Degradation of diazinon and propachlor 121 2. Temperature 126 3. Soil moisture content and bulk density 129 4. Distance moved by diffusion 136 VII. SUMMARY AND CONCLUSIONS 138 VIII. BIBLIOGRAPHY 142 IX. ACKNOWLEDGMENTS 152 iv TABLE OF CONTENTS (continued) Page X. APPENDIX A. COMPUTER PROGRAMS FOR DATA REDUCTION 153 A. Computer Program for Atrazine Analysis on UV Spectrophotometer 153 B. Computer Program for Propachlor and Diazinon Analysis on the Gas Chromatograph 166 XI. APPENDIX B. EXPERIMENTAL DATA 182 XII. APPENDIX C. DATA FOR 1971 FROM GINGLES WATERSHEDS 228 1 I. INTRODUCTION In recent years, pesticides have been added to the list of environ mental pollutants that have aroused national interest in both scientific and lay communities. Today, the public is demanding legislation against the use of some pesticides. In March, 1969, a shipment of 28,000 pounds of Coho salmon was halted by the U. S. Food and Drug Administration because of high concentrations of DDT. DDT has also been responsible for significant losses of lake trout fry in a New York fish hatchery. In 1964, 50 four-pound bags of over-age 15 percent parathion dust was dumped into the Peace River in Florida by a hired farm laborer. Parathion residues were found in the river water for 2 weeks after the parathion bags were discovered (Nicholson, 1970). The effect of pesticides on human health and on our escosystem is not completely known. Pesticides have helped protect our food and fiber from insects and other pests, and have reduced the number of man-hours required to produce a given quantity of crop. Without the use of agricultural chemicals, billions of dollars worth of food would be lost because of weeds, insects, and disease. Since the discovery and use of DDT in 1939, sales of pesti cides have been increasing every year. Surveys and reports of industrial and government economists indicate that synthetic organic pesticide pro duction is increasing at an annual rate of 15 percent with indicated sales of $3 billion by 1975. Since 1963 sales of herbicides have increased 271 percent with a total sales in 1969 of $800 million in the United States (Iowa Department of Agriculture, 1970). With the need for increased food production and the concern for en- 2 vlronmental pollution, it is the responsibility of scientists and engi neers to develop pesticides and application techniques that will do an effective job of controlling weeds, insects, and disease, without pollut ing the environment. There is a lack of knowledge concerning the environ mental hazards of many pesticides. Also, the processes by which pesticides move in the soil are not clearly understood. If scientists and engineers are to develop new application techniques and design equipment that will help provide more effective weed. Insect, and disease control, and reduce the environmental pollution potential of pesticides, they need to gain a better understanding of the factors that affect pesticide movement in soils. This study was initiated to measure the losses of selected pesti cides in runoff and sediment under field conditions and to gain a better understanding of the factors that affect pesticide movement in soils. 3 II. OBJECTIVES The main objectives of the research were: 1. To determine the losses of selected pesticides in runoff water and sediment from small agricultural watersheds planted to corn. 2. To determine the extent of vertical movement in the soil profile and the degradation of selected pesticides on small agricultural watersheds planted to corn under two tillage systems. 3. To gain a better understanding of the factors affecting movement of pesticides in soils and to describe the effect of soil moisture content, soil temperature, and bulk density on movement of selected pesticides in soil by molecular diffusion. 4 III. LITERATURE REVIEW Since 1965, a vast amount of literature has appeared on pesticides. Only selected articles directly related to the author's research were reviewed. Several books and symposium proceedings on pesticides have been published (American Chemical Society, 1966; Soil Science Society of America, 1966; Brady, 1967; Kearney and Kaufman, 1969; Gunther, 1970). Most of the articles in symposium proceedings reviewed recent re search findings and were very helpful in reviewing the pesticide litera ture. The fate of pesticides in the soil-air-plant environment involves many complex processes. Figure 1 shows the major processes involved. These are: 1. adsorption, 2. movement in soil, 3. photodecomposition, 4. microbial degradation, 5. chemical degradation, 6. plant uptake and translocation, 7. volatilization. Articles related to each one of these processes were reviewed. Lambert ^ (1965) classify the factors that affect the fate of any chemical applied to the soil into five major categories: 1. Type of soil: a. makeup; clay, silt, sand, organic matter. b. structure; bulk density, surface area, heterogeneity. Pesticide Applied Soil Surface Volatilization Plant or to Surface Incorporated Air ^ Movement In Intake Soil By Adsorption To Plant Diffusion and To Soil System Mass Flow Particle Losses By Plant Erosion Uptake and Chemical Microbial Photochemical and Surface Degradation Degradation Degradation Translocation Runoff To To Rivers Groundwater Lakes and^ Oceans Figure 1. Flow diagram of processes that a pesticide may undergo in soil-air-plant environment 6 c. prior treatment; chemical, agricultural practices. 2. Type of chemical: Physical properties, solubility, vapor pressure, stability, volatility. 3. Climatic conditions: Rainfall, relative humidity, pressure, temperature, solar radiation. 4. Biological population: Types, nutrient requirement, adaptations, life cycles. 5. Form of chemical: Granular, wettable powder, solvent, emulsion. A. Adsorption of Pesticides Sorption, directly or indirectly, influences the other processes a pesticide may undergo. Adsorption appears to be one of the major factors affecting the interactions occurring between pesticides and soil colloids. Several extensive literature reviews on adsorption have appeared in recent years.