Progress Report. Investigators: Xi Xiong and Dan Lloyd. Objectives:

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1 Progress report Xiong et l. Progress Report Title: Evluting the phosphorus runoff potentil of current home lwn fertiliztion prctices nd recommendtions sed on soil test results Investigtors: Xi Xiong nd Dn Lloyd Ojectives: 1) Determine surfce phosphorus runoff from different fertility progrms pplied to lwns with low (<40 ls P 2 O 5 /cre) nd high (>60 ls P 2 O 5 /cre) soil phosphorus. 2) Evlute the qulity of turfgrss in response to phosphorus tretments pplied to soils with different concentrtions of ville phosphorus. 3) Visully demonstrte to home owners through permnent demonstrtion plots the differences in turfgrss qulity nd phosphorus runoff potentil of different fertiliztion scenrios s relted to soil test vlues. Current sttus/importnce of reserch re: In Missouri, pproximtely 850,700 cres were used for turfgrss cultivtion in 2005, which ccording to current estimtes would mke turfgrss the fourth lrgest crop in Missouri y crege. Turfgrss is fertilized to pply etween ls of N/cre nnully. Mny home owners regulrly use products such s nd pply them t recommended rtes for nitrogen ( ls/cre), which over time hs gretly elevted the soil phosphorus nd potssium levels. Continul fertiliztion of phosphorus on soils tht re in excess of ville phosphorus will increse the likelihood of nutrient loss through surfce runoff nd without providing dditionl enefits to turfgrss helth. Furthermore, surfce runoff of sediment nd nutrients, especilly phosphorus, into surfce wter is growing concern tht cn led to eutrophiction of lkes nd strems. On Jnury 31 st of 2011, the EPA issued finl mndte to the Missouri Deprtment of Nturl Resources to reduce storm-wter runoff into Hinkson Creek y 39.6% ecuse of excessive pollutnts from runoff. This EPA mndte vlidtes the importnce of this reserch, s the Missouri DNR will e seeking res which cn e regulted to reduce pollutnts into Hinkson Creek nd other surfce wters of Missouri. If residentil fertilizer restrictions re proposed, this Fertilizer nd Lime Council funded project will provide relile nd locl dt to ssist in resonle nd reserch sed regultions in hopes of preventing n unnecessry urden on the turf fertilizer industry. Procedures: Design - Twelve plots were estlished on lser leveled 4% slope mesuring 5 ft y 20 ft with two foot uffer etween ech plot. Initil soil phosphorus levels were determined through soil test nd plots were ssigned to high (>60 ls P/cre) nd low <40 ls P/cre) soil phosphorus designtions. The differences in soil P were further mgnified through triple super phosphte (46% of P 2 O 5 ) fertiliztion to develop sustntil difference in soil phosphorus levels for the four corresponding tretments with three replictions. The tretments re homeowner scenrio with high soil P (tretment 1), soil test scenrio with high soil P (tretment 2), soil test scenrio with low soil P (tretment 3), nd restricted scenrio with low soil P (tretment 4) 1

2 Progress report Xiong et l. (Tle 1). Once the soil phosphorus level hd een djusted, one single fll phosphorus ppliction in the mount of 50 ls P/cre ws pplied to tretment 1 (homeowner scenrio with high soil P), nd tretment 3 (soil test scenrio with low soil P). Tretment 2 (soil test scenrio with high soil P) did not receive ny phosphorus tretment s sed on soil test (no dditionl P were needed). Similrly, no phosphorus tretments were pplied to tretment 4 s it is designted s low soil P, yet is restricted use scenrio. After the fll phosphorus ppliction, simulted rinflls (4 inches) were pplied twice in the fll t 0 dy fter tretment (DAT) nd 5 DAT to induce runoff. The reson 0 dy when rinfll ws pplied ws to simulte the extreme condition when homeowners ignored the wether condition nd pplied the phosphorus fertilizer t the sme dy when significnt rinfll occurs. We lso simulted the second rinfll event t 5 DAT to evlute if residue phosphorus exits. Since we hd n unusully dry yer, 4 inches of rinfll ws necessry to induce runoff from tretment re. Tle 1. Phosphorus fertilizer tretments pplied to the runoff plots in Tretment Phosphorus fertiliztion Soil ville phosphorus 1.Common homeowner scenrio 150 ls P 2 O 5 /cre High (>60 ls P 2 O 5 /cre) 2. Soil test recommendtion None (s recommended y soil test) High (>60 ls P 2 O 5 /cre) 3. Soil test recommendtion ls P 2 O 5 /cre (s Low (<40 ls P 2 O 5 /cre) recommended y soil test) 4. Restricted use scenrio None Low (<40 ls P 2 O 5 /cre) Construction Ech 5 ft y 20 ft plot is enclosed y glvnized steel edges tht hve een imedded round ll the edges. Glvnized steel runoff collection oxes mesuring five feet wide, six inches deep, nd eight inches wide were constructed nd instlled down slope from ech of the twelve plots (Figure 1). The collection oxes hve uilt in smple splitter with out one third of the runoff directed to the smple collection ins which consists of 32 gllon collection ins uried 3 ft deep nd removle five gllon ucket for runoff collection. The remining two thirds of the runoff not collected re directed into drin tile trversing the plot. Dringe pipe is 4 inch round dringe tile tht runs down roughly 3% slope t 14 inch depth for out 100 feet, which then tkes 90 degree turn for nother 100 feet down 4% slope t the sme depth which eventully dischrges into swle. Ech collection ox hs een individully clirted to determine the precise percentge of runoff tht is directed to the smple collection ins. Figure 1. Field plots constructed. 2

3 Progress report Xiong et l. Mesurements Runoff wter is collected within 12 hours of simulted rinfll event. Totl volume is determined nd representtive one liter smple is collected nd sent to the MU Soil nd Plnt Testing Lortory for determintion of totl phosphorus, dissolved phosphorus, nd percent sediments. Plnt tissue smples nd soil smples re lso tken nd nlyzed y the Soil nd Plnt Testing Lortory for totl plnt nd soil nutrients including phosphorus. Weekly mesurements (when wether condition permits) include chlorophyll index (Field Scout CM1000), NDVI (GreenSeeker ), nd overll turf qulity on 1-9 scle. Project Accomplishments: Soil phosphorous concentrtions t the initil estimtion dte (August 25) demonstrted tht numericl ut not sttisticlly significnt differences existed etween tretments (Figure 2, lue rs). However, on Novemer 22, tretments 1 nd 2 could e clssified s high soil P while tretments 3 nd 4 could e ctegorized s low soil P (Figure 2, red rs). This would indicte tht we hd estlished tretments within our intended prmeters. Bsed upon fertiliztion of tretments 1 nd 3 on Dy 0, there were significntly higher levels of oth totl P nd dissolved P collected in runoff wter compred to tretments 2 nd 4 (Tle 2). Totl P ws 6.94-fold higher for tretment 1 compred to tretment 2. This suggests tht for soils with high P levels, high rinfll shortly fter ppliction of P fertilizer results in significnt loss of tht P. Similrly, high rinfll shortly fter ppliction of P fertilizer on soils with low P levels lso results in significnt loss of P (7.04-fold) compred to tretment 4. However, P ppliction pplied on soil with high P level (tretment 1) resulted in significntly higher totl runoff P loss thn pplied to plots with low soil P level (tretment 3). This result indicted tht ccumulted higher soil P level will likely increse the chnce of runoff P loss. These sme trends nd level of significnce were lso mesured for P dissolved in wter (Tle 2). In exmining the sediment P levels, we oserved tht some differences were noted mong tretments, ut this ws not significnt. It ws quite interesting to note tht of the totl P estimted from tretments 2 nd 4 (no dditionl P dded t dy 0), 92.3% nd 94.4% were represented y sediment P from tretments 2 nd 4, respectively. These dt suggest tht some P ws lost from tretments 2 nd 4, ut this ws represented primrily y P ttched to sediment. For tretments 1 nd 3, only up to 34% of the P ws lost in sediment. The mount of runoff ws similr for the four tretments. For 5 DAT, numericl differences in totl, dissolved, nd sediment P were noted etween tretments, ut differences were not sttisticlly significnt. The impct of the P levels ws influenced y the numericl differences in runoff wter collected. On concentrtion sis (mount of runoff wter collected tken into considertion), totl P (mg/l) nd totl dissolved P (mg/l) were significntly higher for plots receiving P just prior to high rinfll event (0 DAT) compred to plots tht did not receive P (Figure 3A nd B). At 5 DAT, levels of totl P nd dissolved P were quntittively similr t oth the high nd low soil P levels. These dt indicte tht mjority of the potentil P lost with high rinfll events will occur with the first event. Minerliztion of tll fescue tissue on Decemer 9 (18 DAT) showed differences for P mong tretments ut not N or K (Tle 3). The P (in %) in tissue smples from high P soils (tretment 3

4 Progress report Xiong et l. 1 nd 2) wre significnt higher thn the tissue smples collected from the low soil P plots (tretment 3 nd 4). This result corresponds with the soil P level presented t Figure 2. Estimtes of turf helth over 25 dy period following ppliction of P nd high rinfll were similr for the four tretments (Tle 4). Among ll the vriles of turf helth, only NDVI mesured t 10 DAT showed differences etween tretments. Higher NDVI vlues would correlte with etter turf color nd coverge, ut differences etween tretments could not e ssocited with P levels. Our dt indicte tht the reltive P levels in the soil did not contriute to n ility to ssess the tll fescue growing in plots with tht tretment s helthier. Rinfll mounts in the experimentl re were low over the durtion of the study (Figure 4). As result, the soil moisture potentil ws low nd high rinfll events of 4 inches were necessry to induce runoff from the plots. In summry, our preliminry dt demonstrte tht improper ppliction of P fertiliztion does increse the chnce of loss P through runoff. Ojective for yer two (2012): The second yer of this experiment will e repeting the tretments nd mesurements s we conducted in It is importnt for field-sed project to vlidte results y collecting dt from different growing sesons, s the yer-to-yer vrince of environmentl conditions re expected. This pst yer hs een extremely dry nd we were not le to collect ny runoff dt from nturl rinflls. In 2012, we pln to put down tretments oth in spring nd fll, nd hopefully we re le to collect dt from oth simulted nd nturl rinflls. For the second yer of this study, we re lso redy to demonstrte nd present the results to the generl pulic through the Turf nd Ornmentl Field dy in summer, nd Lwn-cre workshop in spring. At the end of the second seson, we re lso plnning to present the results to the Missouri Green Industry Conference in Decemer. Proposed udget for yer two (2012): Ctegory Yer 2 Slry nd enefits (20% Reserch Specilist) 9,373 Supplies (fertilizer, smpling gs) * 500 Soil testing services** 5,000 Totl 14,873 * Supplies include fertilizer, smpling gs, seeds, pesticides, nd other necessry consumles. ** Soil testing services include estimtes for two soil smples, two tissue smples, nd six runoff wter smples in 2012 from ech plot. 4

5 Bry I P (l/c) Progress report Xiong et l. Figure 2. Soil phosphorus (P) concentrtion (l/c) mesured y Bry I P efore nd fter P fertilizer tretments. Soil smples were rndomly tken from 5 different loctions within ech plot nd mixed for nlysis. Brs leled y different letters efore or fter P tretment re not significntly different using Fisher s Protected LSD (P=0.05) Trt1 Trt2 Trt3 Trt4 efore P tretment fter P tretment 5

6 Totl dissolved P (mg/l) Totl P (mg/l) Progress report Xiong et l. Figure 3. Concentrtions of totl P (mg/l) nd dissolved P (mg/l) in runoff wter collected t 0 (A) or 5 (B) dys fter the P fertilizer tretment (DAT). Brs leled y different letters t 0 or 5 DAT re not significntly different using Fisher s Protected LSD (P=0.05). A Trt1 Trt2 Trt3 Trt4 0DAT 5DAT B c c Trt1 Trt2 0DAT 5DAT Trt3 Trt4 6

7 Precipittion (inch) Progress report Xiong et l. Figure 4. Precipittion (inches) t the South Frm during fll, /1 9/8 9/15 9/22 9/29 10/6 10/13 10/20 10/27 11/3 11/10 11/17 11/24 12/1 12/8 12/15 Dte 7

8 Progress report _ Xiong et l. Tle 2. Totl phosphorus loss in the runoff wter from the plot re ffected y the P fertilizer tretments t the different dys fter tretments (DAT). Dt included re totl P (mg), dissolved P (mg), sediment P (mg), nd the totl runoff (L) from the plot re. Trt # Soil P Prctice ---Totl P (mg) Dissolved P (mg) Sediment P (mg) * Runoff (L) DAT 5DAT 0DAT 5DAT 0DAT 5DAT 0DAT 5DAT 1 High P Home owner ** High P Soil test 48.1c c Low P Soil test Low P Restricted use 28.4c c * Sediment P (mg) is indirectly presented y the difference etween the totl P nd dissolved P. ** Men seprtion is conducted only when significnt differences were found y ANOVA. Mens within column followed y the sme letter re not significntly different using Fisher s Protected LSD (P=0.05). Tle 3. Turfgrss tissue minerl concentrtions, percent nitrogen (N%), phosphorous (P%), nd potssium (K%) influenced y the P fertilizer tretments. Trt # Soil P Prctice N% * P% K% 1 High P Home owner High P Soil test Low P Soil test c Low P Restricted use c 1.56 * Clipping smples were collected from the plot re nd nlyzed in the Soil nd Plnt Testing Lortory nd reported s percent (%) dry mtter. 8

9 Progress report _ Xiong et l. Tle 4. Turf qulity, cnopy chlorophyll index, nd Normlized Difference Vegettion Index (NDVI) ffected y P fertilizer tretments. Dt were collected t different dys fter tretments (DAT). Trt # Soil P Prctice Turf qulity * Chlorophyll Index ** NDVI DAT 10DAT 19DAT 25DAT 1DAT 10DAT 19DAT 25DAT 10DAT 19DAT 25DAT 1 High P Home owner High P Soil test Low P Soil test Low P Restricted use * Turf qulity were visully ssessed t 1-9 scle where 9 represents idel turf, 1 represents ded turf, nd 6 represents minimlly cceptle turf qulity; ** Chlorophyll index were collected y using field scout CM1000 reflectnce meter (Spectrum technologies, Plinfield, IL) nd verged three rndom redings per plot; Normlized difference vegettion index (NDVI) were recorded using GreenSeeker (NTech Industries, Inc., Uklh, CA); Mens followed within column followed y the sme letter re not significntly different using Fisher s Protected LSD (P=0.05). 9