Supplemental Material

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1 Supplementl Mteril Sulfmethzine Sorption to Soil: Vegettive Mngement, ph, nd Dissolved Orgni Mtter Effets Bei Chu, Keith W. Goyne *, Stephen H. Anderson, Chung-Ho Lin 2, nd Roert N. Lerh 3 Deprtment of Soil, Environmentl nd Atmospheri Sienes, University of Missouri, 302 ABNR Building, Columi, MO Center for Agroforestry, University of Missouri, 203 ABNR Building, Columi, MO USDA ARS, Cropping Systems nd Wter Qulity Reserh Unit, 269 Ag. Eng. Bldg., Columi, MO 652 * Corresponding Author: e-mil, goynek@missouri.edu; telephone, (573) ; fx, (573)

2 Chrteriztion of Dissolved Orgni Mtter The dissolved orgni ron (DOC) nd totl nitrogen (TN) ontents of dilyzed DOM solutions were determined using Shimdzu TOC-V CSH totl orgni ron nlyzer equipped with TNM- totl nitrogen mesuring unit nd ASI utosmpler (Shimdzu Corp., Kyoto, Jpn). The verge DOC nd TN ontents in the DOM were found to e 380 g kg - nd 60 g kg -, respetively. Ultrviolet-visile (UV-VIS) spetrosopy ws used to determine the E4/E6 rtio (rtio of sorne t 465 nm to 665 nm) nd molr sorptivity (ε) mesured t wvelength of 280 nm normlized to DOC onentrtion (Chin et l., 994; Swift, 996). Reltionship etween ε nd romtiity nd weight-verged moleulr weight (M W ) ws lulted using equtions developed y Chin et l. (994): romtiity = 0.05ε , r 2 =0.90; M w = 3.99ε + 490, r 2 =0.97. The E4/E6 rtio nd ε were found to e 6.55 nd 35 L mol C - m -, respetively, romtiity ws lulted to e 23%, nd the verge moleulr weight ws estimted to e 746 D. Totl idity nd roxylte idity of the extrted DOM ws mesured y titrtion methods desried y Swift (996). Briefly, 0.36 g freeze-dried DOM ws dissolved in 0. M NCl. Then the solution ws mixed with suffiient 0.05 M HCl to lower the ph to 3.0. The solution ws titrted with ronte-free 0. M NOH under nitrogen tmosphere to ph 0.5. The roxyl group ontent ws determined s the vlue of hrge t ph 8, nd the phenoli group ontent ws determined s the hrge etween ph 8 nd 0. The roxyl nd phenoli group ontent ws lulted to e 6.26 nd 0.73 mol hrge kg - DOM, respetively. The totl idity, 6.99 mol hrge kg - DOM, ws estimted y the sum of roxyli nd phenoli idity. S2

3 Chrteriztion of Cly Minerlogy Cly minerlogy ws nlyzed with X-ry diffrtion (XRD). Cly smples were prepred sed on the proedures of Hrris nd White (2008). Briefly, 35 g of ir-dried soils (<2.0 mm) were rinsed with 00 ml wter three times to remove solule slts. Smples were then treted with 25 ml of 30% H 2 O 2 t 80 o C to remove orgni mtter. Iron oxides were removed y dding 4 g of sodium dithionite nd 00 ml of itrte uffer (premix M sodium ironte nd 0.3 M sodium itrte t rtio :8) t 80 o C. The ly frtion (<2μm) ws seprted y entrifugtion. Cly smples from eh soil were sturted with either K or Mg. The ly suspension ws vuum filtered through 47 mm dimeter, 0.45 µm Millipore memrne filter until suffiient mount of ly settled on the memrne. The filter holder ws then disssemled nd the moist memrne ws pled on len glss slide with the ly smple ontting the slide. The slides were ir-dried nd the memrne ws peeled off with re; multiple slides ontining K- sturted lys were prepred to permit ir-dried, 300 o C nd 550 o C het-treted smples to e nlyzed using X-ry diffrtion (XRD). Mgnesium-sturted smples were lso treted with ethylene glyol vpor. Diffrtion ptterns of K-sturted (25ºC, 300ºC nd 550 ºC) smples nd Mg-sturted (ir-dry nd ethylene glyol treted) smples were otined. All XRD ptterns were olleted using Sintg Pd V diffrtometer equipped with spinning stge nd EG&G Orte LN2 SS detetor using Ni-filtered CuKα rdition t 40 kv nd 30 ma. A ontinuous sn mode ws used to ollet 2θ dt from o with step size of pproximtely 0.0 o. The divergent slit size ws 0.05 mm. S3

4 Mthemtil Desription of Sorption Dt The mount of SMZ dsored to eh soil smple ws lulted from: q ds ( Cds, B )( VB ) ( Cds, S )( Vs ) = [] m S where q ds is the surfe exess of SMZ (i.e., mount dsored) fter the retion period (µmol kg - ), C ds,b nd C ds, S re the equilirium SMZ onentrtions (µmol L - ) in lnk (B) nd smples (S) fter retion, V B nd V S re the volume of solution (L) dded to smples nd lnks, nd m S is mss of soil (kg) dded to the retion vessel (Essington 2004). Surfe exess of SMZ fter suessive desorption steps (q des ) ws lulted s follows: q des = q ds m i= ( C des, i )( Vdes, i ) ( Cdes, i )( Vent, i ) m S [2] where m equls the totl numer of i desorption steps ( to 4) nd instnes where m = 0 (i=) the vlues were otined from dsorption dt, C des is equilirium SMZ onentrtion in solution fter the desorption retion period, V des is the volume of kground eletrolyte solution in the retion vessel during desorption phse, nd V ent is the volume of entrined solution remining in the soil pellet fter removl of superntnt from the vessel. This eqution ws modified from tht used y Goyne et l. (2004). S4

5 K d (L kg - ) Armstrong Huntington Menfro K d (L kg - ) Row Crop Grss VBS Agroforestry VBS Initil SMZ Conentrtion (µm) Initil SMZ Conentrtion (µm) 4 3 SMZ SMZ + DOM K d (L kg - ) Initil SMZ Conentrtion (µm) Figure S. Anlysis of vrine results for min ftors effets on solid-to-solution distriution oeffiient vlues (K d ): () soil; () vegettive tretment; nd () dissolved orgni mtter (DOM). Brs with the sme letters were not signifintly different t p <0.05. (VBS vegettive uffer strip). S5

6 Tle S. Solid-to-solution distriution oeffiients (K d ) for sulfmethzine dsorption t multiple initil onentrtions to row-rop (RC), grss uffer strip (GBS), nd groforestry uffer strip (ABS) soils in presene nd sene of > 000 D DOM (50 mg L - OC). The 95% onfidene intervls (CI) surrounding the men vlues re presented. Soil Vegettion Phse K d ± 95% CI 2.5 µm 0 µm 8 µm 25 µm 50 µm L kg Armstrong RC SMZ.7 ± ± ± ± ± 0.20 SMZ +DOM.97 ± ± ± ± ± 0.09 GBS SMZ 2.89 ± ± ± ± ± 0.25 SMZ +DOM 2.95 ± ± ± ± ± 0.03 ABS SMZ.35 ± ± ± ± ± 0.0 SMZ +DOM 2.27 ± ± ± ± ± 0.04 Huntington RC SMZ 0.66 ± ± ± ± ± 0.0 SMZ +DOM.37 ± ± ± ± ± 0.08 GBS SMZ.69 ± ± ± ± ± 0.0 SMZ +DOM.63 ± ± ± ± ± 0.03 ABS SMZ 5.3 ± ± ± ± ± 0.06 SMZ +DOM 3.96 ± ± ± ± ± 0.03 Menfro RC SMZ 2.03 ± ± ± ± ± 0.04 SMZ +DOM.87 ± ± ± ± ± 0.3 GBS SMZ.25 ± ± ± ± ± 0.05 SMZ +DOM 2.04 ± ± ± ± ± 0.20 ABS SMZ 2.82 ± ± ± ± ± 0.5 SMZ +DOM 2.53 ± ± ± ± ± 0.03 S6

7 Tle S2. Sorption (q) of > 000 D dissolved orgni mtter to soils under row-rop (RC), grss uffer strip (GBS), nd groforestry uffer strip (ABS) mngement mesured s loss of dissolved orgni ron from solution. Error represents the 95% onfidene intervl. Soil Vegettion q mg kg - Armstrong RC 43 ± 0 GBS NS ABS 3± 4 Huntington RC 6 ± 6 GBS 37 ± 6 ABS NS Menfro RC 8 ± 2 GBS 6 ± ABS NS NS, no sorption or negtive sorption oserved. S7

8 Referenes Chin, Y.P., G. Aiken, nd E. O'Loughlin Moleulr weight, polydispersity, nd spetrosopi properties of quti humi sustnes. Environ. Si. Tehnol. 28: Essington, M. E Soil nd wter hemistry: An integrted pproh. CRC Press, Bo Rton, FL. Goyne, K.W., J. Chorover, A.R. Zimmermn, S. Komrneni, nd S.L. Brntley Influene of mesoporosity on the sorption of 2,4-dihlorophenoxyeti id onto lumin nd sili. J. Colloid Interfe Si. 272: Hrris, W., nd N. White X-Ry diffrtion tehniques for soil minerl identifition. p In D.L. Drees nd A.L Ulery (eds.) Methods of Soil Anlysis, Prt 5. Minerlogil Methods. SSSA, Mdison, WI. Swift, R.S Orgni mtter hrteriztion. p In D.L. Sprks (ed.) Methods of Soil Anlysis, Prt 3. Chemil Methods. SSSA, Mdison. WI. S8