INCORPORATION OF CONTROLLED-RELEASE FERTILIZER IN A SEEPAGE IRRIGATED TOMATO FERTILITY PROGRAM IN FLORIDA By LUTHER C. CARSON A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2014 1 © 2014 Luther C. Carson 2 To my parents and my family 3 ACKNOWLEDGMENTS I thank my advisor, Dr. Monica Ozores-Hampton, for her guidance and support throughout my doctoral program. I am also thankful to my supervisory committee, Dr. Sartain, Dr. Obreza, Dr. Morgan, and Dr. Sargent, who provided time, comments on my project, and laboratory space and supplies in which to conduct research. A special thanks goes to the staff of the Southwest Florida Research and Education Center’s Vegetable Horticulture Laboratory (Kiran, Aline, Joel, Ozzy, Dago, and Stacy) and the staff of the Soil Fertility and Turf Grass Nutrition Laboratory (Dolly, Nahid, and Dawn) for their assistance during my laboratory research. I am grateful to Garguilo Farms for their invaluable contributions to my research. Finally, I thank my family and friends for the love and support that they have given during my PhD, which has given me the inspiration to complete this degree. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS .................................................................................................. 4 LIST OF FIGURES ........................................................................................................ 11 LIST OF ABBREVIATIONS ........................................................................................... 12 ABSTRACT ................................................................................................................... 16 CHAPTER 1 BACKGROUND AND LITERATURE REVIEW ....................................................... 18 Background ............................................................................................................. 18 Literature Review .................................................................................................... 22 Tomato Nitrogen Uptake .................................................................................. 22 Florida Fertilization Practices in Seepage Irrigated Crops ................................ 25 What are Enhanced Efficiency Fertilizer and Controlled-Release Fertilizer?.... 26 Factors Affecting Controlled-Release Fertilizer Nutrient Release for Vegetable Production in Florida using Seepage Irrigation ............................ 28 Temperature .............................................................................................. 28 Soil moisture .............................................................................................. 30 Osmotic potential ....................................................................................... 30 Soil pH ....................................................................................................... 31 Soil microbial populations .......................................................................... 31 Soil texture ................................................................................................. 32 Controlled-release fertilizer composition .................................................... 32 Coating thickness, type, and prill diameter................................................. 33 Cultural Practices Affecting CRF Release Duration ......................................... 34 CRF field placement .................................................................................. 34 Nitrogen rate supplied from CRFs .............................................................. 36 CRF application timing ............................................................................... 37 Fumigation and staged planting ................................................................. 38 Methods for Determining Nitrogen Release from Controlled-Release Fertilizers used for Vegetable Production ..................................................... 39 Laboratory methods for determining controlled-release fertilizer nutrient release duration ...................................................................................... 39 Field methods for determining nitrogen release from controlled-release fertilizers ................................................................................................. 41 Correlations between methods .................................................................. 43 Procedure to measure N ............................................................................ 43 Fresh-Market Tomato Harvest, Ripening, and Quality ..................................... 46 Fruit quality aspects of ripe, round tomatoes ............................................. 46 Tomato maturity ......................................................................................... 48 5 Determining when to harvest; Problems with green harvest ...................... 49 Stages of commercial harvest (6 USDA ripeness stages):-Why pick green? .................................................................................................... 49 Pre-harvest nutritional program effects on fruit quality ............................... 51 Packinghouse operations: washing, sorting, sizing, packing, and ripening ................................................................................................... 52 Temperature and ethylene management ................................................... 53 Shipping ..................................................................................................... 54 Hypotheses ............................................................................................................. 54 2 NITROGEN RELEASE PROPERTIES OF CONTROLLED-RELEASE FERTILIZERS IN TOMATO PRODUCTION OF SOUTH FLORIDA ....................... 67 Introduction ............................................................................................................. 67 Material and Methods ............................................................................................. 69 Results and Discussion........................................................................................... 72 Weather Conditions .......................................................................................... 72 Soil Temperature .............................................................................................. 72 Measured Nitrogen Release from Field Incubated Pouches ............................ 73 Non-Linear Regression Analysis of Nitrogen Release ...................................... 75 Days to 75% Nitrogen Release ........................................................................ 77 3 PREDICTION OF CONTROLLED-RELEASE FERTILIZER NITROGEN RELEASE IN TOMATO PRODUCTION USING ON-FARM POUCH AND ACCELERATED TEMPERATURE CONTROLLED INCUBATION LABORATORY METHODS .................................................................................... 89 Introduction ............................................................................................................. 89 Material and Methods ............................................................................................. 91 Accelerated Temperature Controlled Incubation Method ................................. 91 Pouch Method Field Study ............................................................................... 92 Correlation of the ATCIM with the Pouch Method Using a Two-Step Process ......................................................................................................... 94 Results and Discussion........................................................................................... 95 Accelerated Temperature Controlled Incubation Method ................................. 95 Prediction Model: Correlation of ATCIM and Pouch N Release ....................... 96 Prediction Model: Correlation of the ATCIM and the Pouch N Release Grouped by CRF Release Duration .............................................................. 98 4 EFFECT OF CONTROLLED-RELEASE AND SOLUBLE FERTILIZER ON TOMATO PRODUCTION AND POSTHARVEST QUALITY IN SEEPAGE IRRIGATION ......................................................................................................... 109 Introduction ........................................................................................................... 109 Material and Methods ........................................................................................... 112 Results and Discussion......................................................................................... 115 Weather Conditions ........................................................................................ 115 6 Soil Temperatures .......................................................................................... 116 Water Table Depth ......................................................................................... 117 Plant Nutritional Status ................................................................................... 117 Yield Responses to CRF N Rates .................................................................. 118 Post-Season Soil Samples ............................................................................. 121 Postharvest Quality ........................................................................................ 123 5 EFFECT OFCONTROLLED-RELEASE FERTILIZER NITROGEN RATE, PLACEMENT, SOURCE,