0 100 200 300 400 500 600 700 800 seepage center pivot seepage center pivot seepage center pivot seepage center pivot Farm 1 Farm 2 Farm 3 Farm 4 Overall water usage (mm) Seepage Pivot Rainfall Seepage vs. Center Pivot for Potato Production in SW Florida Yuqi Cui, Guodong Liu, Lincoln Zotarelli, Crystal A. Snodgrass, and Alan Jones UF-IFAS, Gainesville, FL 32611, Manatee County Extension, IFAS, Palmetto, FL 34221, and Jones Potato Farm, Parrish, FL 34219 INTRODUCTION RESULTS Potato Yields MATERIALS & METHODS Water Usage Seepage is the predominant irrigation for potato production in Florida, but poses problems such as 1) water conservation and 2) water quality. Overhead irrigation is significantly greater in water-use efficiency as compared to seepage irrigation. Objective: to quantify the water savings of converting seepage to center pivot for potato production in SW Florida. Farm Irrigation Variety Acreage (ha) Planting Date Harvest Date Farm 1 Seepage Red LaSoda 4 10/12/14 1/23/15 Central Pivot Red LaSoda 69 10/12/14 1/23/15 Farm 2 Seepage Red LaSoda 10 10/19/14 1/23/15 Central Pivot Red LaSoda 57 10/12/14 1/23/15 Farm 3 Seepage Red LaSoda 3 12/5/14 3/23/15 Central Pivot Red LaSoda 83 12/5/14 3/23/15 Farm 4 Seepage Accumulator 49 12/18/14 3/23/15 Central Pivot Accumulator 121 12/18/14 3/23/15 2014-2015 Growing Season NO 3 -N Level in Soil at Harvest Leaf greenness Field Measurements 33% 18% 49% 27% 18% 55% 18% 25% 57% 1% 66% 33% Moisture This research was financially supported by Southwest Florida Water Management District (13C00000017). We thank Mr. David Fleming and Mr. Jesse Cavillo for helping with the research. ACKNOWLEDGEMENTS Center pivot irrigation system can save more than 50% of irrigation water as compared with seepage irrigation. A more suitable fertilization program may be required. (e.g., fertigation) CONCLUSIONS Leaf water potential Rain gauge Center pivot Leaf greenness Soil moisture Flow meter 0 10 20 30 40 50 seepage center pivot seepage center pivot seepage center pivot seepage center pivot Farm 1 Farm 2 Farm 3 Farm 4 Leaf greennes (SPAD readings) a b a a b b P<0.01 P<0.01 P<0.05 P>0.47 0 10 20 30 40 50 60 70 80 90 seepage center pivot seepage center pivot seepage center pivot seepage center pivot Farm 1 Farm 2 Farm 3 Farm 4 Soil NO 3 -N (mg/kg) a b P<0.01 P>0.48 P>0.71 P>0.73 0 100 200 300 400 500 600 700 800 seepage center pivot seepage center pivot seepage center pivot seepage center pivot Farm 1 Farm 2 Farm 3 Farm 4 Yield (kg/ha) a b P<0.01 P>0.39 P>0.10 P>0.83 0 5 10 15 20 25 30 35 40 45 1/28 2/7 2/17 2/27 3/9 3/19 Volumetric water content (%) Date Farm 4 - Seepage 4'' Depth 8'' Depth 12'' Depth 20'' Depth 28'' Depth 0 5 10 15 20 25 30 35 40 45 1/28 2/7 2/17 2/27 3/9 3/19 Volumetric water content (%) Date Farm 4 - Center pivot Seepage 0 20 40 60 80 100 120 140 seepage center pivot seepage center pivot seepage center pivot seepage center pivot Farm 1 Farm 2 Farm 3 Farm 4 Irrigation water-use efficiency (L/kg tubers) P<0.01 b a a b a b b a P<0.01 P<0.01 P<0.01