METHYLENE UREA - A CONTROLLED RELEASE NITROGEN SOURCE FOR TURFGRASSES George R. McVey Senior Technical Associate 0. M. Scott & Sons Company

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1 METHYLENE UREA A CONTROLLED RELEASE NTROGEN SOURCE FOR TURFGRASSES Geoge R. McVey Seno Techncal Assocate. M. Scott & Sons Company Maysvlle, Oho 434 The development of ntogen poducts deved fom condensng uea wth fomaldehyde epesented a sgnfcant advance n ntogen fetlze technology. Ths technology povded the bass fo developng ntogen contanng fetlze poducts wth some popetes smla to natual oganc ntogen souces. These smlates nclude () a contolled elease of ntogen and (2) a low bun potental. Addtonal benefcal popetes ove natual ogancs ntogen souces povded by ueafomaldehyde condensaton poducts nclude () hgh ntogen analyss (38% vs. less than % ntogen), (2) excellent consstency, (3) mpoved flexblty n adustng ntogen elease chaactestcs, (4) odoless, and (5) economcal. Accodng to a epot n Maketng Reseach Repot on Contolled Release Fetlzes by Jeane H. Ayes, Chemcal Economcs Handbook, Menlo Pak, Calfona (Oct. 978), ntogen deved fom uea fomaldehyde condensaton poducts accounted fo 9% of all the contolled elease ntogen consumed n the Unted States. Whle the genec name "ueafom" and ueafomaldehyde has been used fo a numbe of yeas to descbe the condensaton poducts of uea and fomaldehyde, t has been suggested ('Donnell, pesonal communcaton, 976) that methylene uea (MU) would be techncally moe accuate. Ths name, methylene uea, shall be used n the dscusson to follow. The ealy poneeng eseach caed out at the USDA and epoted n 946 by Yee and Love (Poc. Sol Scence Soc. Ame.,, 389) showed that a ntogen poduct wth contolled avalablty could be made by condensng uea wth fomaldehyde unde specfc eacton condtons. Followng ths ntal eseach, two dstnct categoes of methylene uea poducts wee commecalzed. These two categoes dffeed pmaly n the solublty chaactestcs as affected by the dstbuton of the mxtue of methylene uea polymes n the fnal poduct plus the level of uneacted uea. Manufactung Poducton of methylene uea eques exact contol of tempeatue, ph, eacton tme and eacton components. The elease chaactestcs can be contolled by modfyng the eacton vaables. As shown n Table, thee ae 6 basc components equed fo poducton of methylene uea. Uea and fomaldehyde ae the mao components whle sulfuc acd, sodum hydoxde and sufactant ae only equed n molecula quanttes. n the eacton pocess, uea eacts wth fomaldehyde to poduce monomethyl ol uea whch futhe eacts wth uea to poduce methylene uea vayng n chan length (2 to 5 uea molecules, o possbly even hghe, attached togethe wth methylene goups). (Table 2). The manufactung of these poducts dffes elatve to the ato of uea to fomaldehyde used and the eacton condtons. D. John Hays on the panel wll dscuss the poducts common to Categoy whle my dscusson wll be on the methylene uea poducts of a second mao goup, Categoy 2 (see Table 3). 6

2 Chemcal Popetes As a bass to gve you some backgound on the two mao categoes of methylene uea poducts, typcal chemcal chaactestcs ae shown n Table 3. A futhe beakdown on the dstbuton of ntogen components wthn the solublty factons wll also help to chaacteze dffeences n these two categoes (see Table 4). The ntogen elease chaactestcs of methylene uea can be contolled by the method of manufactung selected. Analytcally the elease chaactestcs ae classfed by the solublty of ths poduct n wate vayng n tempeatue. Two tempeatues ae selected () oom tempeatue (22 C) and (2) bolng wate ( C). Based on the solublty at these two tempeatues, the bologcal actvty can be pedcted. As shown n Fgue as the pecent of the cold wate nsoluble ntogen whch s soluble n hot wate deceases (NA), the ntfcaton ate (conveson of methylene uea to ntates) deceases. The ntfcaton ate s damatcally educed as compaed to ammonum sulfate and uea. Ths ate can be educed to a pont whch s elatvely bologcally nactve. One of the pmay benefts of methylene uea s attbuted to ts low salt ndex. As shown n Table 5, the low salt ndex at equal ates of mateal s damatcally educed as compaed to conventonal fast elease N souces. These dffeences ae even moe damatc when compaed on an equal ntogen bass. Snce the salt ndex s a measue of bun potental, t s obvous that on an equal weght o equal N bass, methylene uea would have a much lowe bun potental as compaed to soluble N souces. The slow elease chaactestcs of methylene uea ae also eflected n the ate of conveson to ammonacal and ntate ntogen n the sol. As shown n Fgue 2 and 3, the ammonacal ntogen level n the sol soluton s up to 4 tmes hghe when teated wth uea as compaed to the methylene uea. Afte 6 weeks, the ammonacal ntogen level s essentally zeo egadless of ntogen souce. n contast, the ntate ntogen level damatcally nceases as the ammonacal ntogen level deceases. Ths was only evdent f the ntogen souce was methylene uea (Fgue 3). The ntate ntogen level contnues at a hgh level fo 2 days (5 ppm) f the sol was teated wth methylene uea. n contast, sol teated wth uea newe had a ntate level geate than 3 ppm. Uea eadly leaches fom the meda befoe conveson of uea to ntates can be ealzed. Bologcal Popetes Contolled elease ntogen souces ae often chaactezed by mpoved safety, nceased esdual, a moe unfom gowth patten and less total clppng emoval as compaed to tuf teated wth soluble ntogen souces. As shown n Table 6 as the pecent cold wate nsoluble ntogen nceases, the degee of nuy deceases. These dffeences ae moe damatc when the fetlze s appled to wet tuf, howeve, stll ae appaent on dy tuf. At a cold wate nsoluble ntogen (CWN) of 42%, nuy was not obectonal at all ates (4 b. N/M) o methods of applcaton (wet vs. dy folage). n contast, complete fomulatons contanng only 2% CWN caused exteme fola nuy when appled to wet folage usng only lb. of N/ sq ft. unde the condtons of ths study (appled n late August unde hgh tempeatue condtons). When compang methylene uea fom Categoy to Categoy 2 elatve to tuf esponse, a substantal dffeence n tuf colo was noted. As shown n Table 7, the spng geenng esponse fom a late fall fetlzaton was vey slow when tuf was teated wth ueafom (Categoy ) but was damatcally nceased when 6

3 teated wth methylene uea (Categoy 2). n ths same expement, the ntogen souce BDU was also ncluded. ntal esponse was compaable to ueafom whle the esdual of methylene uea and ueafom was longe than fo BDU (see Table 7). Spng applcaton of BDU and methylene uea (Categoy 2) wee compaed (see Table 8). n ths study, ntal geenng was vey slow when teated wth BDU even though ates of 2 lbs. of ntogen pe sq. ft. wee appled. n contast, tuf teated wth methylene uea exhbted a apd spng geenng esponse. The esdual chaactestcs of these poducts wee smla. The esdual of the methylene uea (Categoy 2) was compaed to uea. As shown n Fgue 4, the ntal suge of gowth was educed fom.9 gams fo tuf teated wth uea down to. gams when the tuf was teated wth methylene uea (42% educton n fesh weght). The educton n ntal suge gowth s eflected n the esdual. These dffeences ae not damatc fom only one applcaton, howeve. When epeat applcatons of methylene uea fom Categoy 2 wee used, the esdual chaactestcs became moe appaent as shown n Fgue 5. n ths study, the fetlze pogam was dscontnued n the fall of the 2nd yea. Clppng fesh weghts n the spng of the 3d yea damatcally eflected the esdual chaactestcs when methylene uea contanng 42% CWN was compaed to a poduct contanng 2% CWN. The colo of the tuf teated wth the contolled elease ntogen souce ( % CWN) was compaable to tuf teated wth the fast elease N souce (64 2% CWN) n 27 out of 32 obsevatons ove a 2 /2 yea peod (see Fgue 6). Tuf gowth s anothe measue of the contolled elease popetes of methylene uea. The total fesh weght of clppngs can be substantally educed when tuf s teated wth methylene uea as compaed to uea. As shown n Table 9, clppngs emoved ove a 6 week peod was educed by one thd when Kentucky bluegass was teated wth methylene uea as compaed to uea. The lowe clppng emoval s eflected n less tendency fo scalpng because of delayed mowng, a educton n mowng fequency and less labo fo collectng and emovng clppngs. n anothe expement, we compaed two knds of methylene uea souces fom Categoy 2 (see Table ). Two poducts vayng n pecent CWN wee appled n ealy Octobe to Kentucky bluegass. Whle t s often epoted that methylene uea poducts wll not povde a good colo and gowth esponse unde cool sol condtons, these esults ae to the contay. The poduct contanng 36% CWN nduced bette tuf colo than poducts contanng 5% CWN suggestng geenng esponse s assocated wth the pecent CWN n the poduct. Ths agan llustates the flexblty n fomulatng methylene uea poducts to meet the bologcal demands of tuf. Summay ) The popetes of two goups of methylene uea, othe slow elease ntogen souces and soluble ntogen souces vay wdely elatve to chemcal and bologcal popetes. 2) Vayng the wate soluble and nsoluble chaactestcs of methylene uea of Categoy 2 (see Table 4) povdes substantal flexblty n manufactung poducts to meet vaed use condtons fo tufgass. 3) The methylene uea ntogen souces offe advantages elatve to tuf toleance, lesse gowth esponse, nceased ntogen effcency and educton n polluton potental as compaed to soluble ntogen souces. Ths technology has addtonal benefts whch have been ovelooked ove the yeas. The polluton potental of ntogen can be educed by ths technology. Ths has ceated a enewed nteest n methylene uea n many aeas of agcultue. 62

4 Table. Mateals Used n the Poducton of Methylene Ueas Compound Uea UFC (6% Uea) Sulfuc Acd Sodum Hydoxde Wate Functon Ntogen Souce Fomaldehyde Souce (25%) Catalyst Stablze Dluent Relatve Popotons Sufactant Foamng Agent 63

5 Table 2. Symbolc Repesentaton of Methylene Uea Condensaton Reacton Monomethylol Uea ( U ) Monomethylol Uea Methylene Duea Methylene Duea u) +#( u ) Dmethylene Tuea C Dmethylene Tuea U XMX U Tmethylene Tetauea Symbols ( U ) (Uea), <F> (UFC), [T] (Sulfuc Acd) (Sodum hydoxde), (H) (Wate), A (Sufactant) (Methylene Goup) 64

6 Table 3. Ntogen Chaactestcs of Typcal Methylene Uea Poducts Commecally Avalable. Ntogen Chaactestcs Categoy ' Categoy 2' Pecent Total Ntogen % Ntogen Actve ndex (NA) Cold Wate Soluble Ntogen (CWSN) Cold Wate nsoluble Ntogen (CWN) / Ueafom (Hecules ncopoated and E.. dupont de Nemous & Company, nc.) 2/ Methylene ueas (O..M. Scott & Sons) 65

7 Table 4. Appoxmate Dstbuton of Methylene Uea Factons and Uea n Commecally Avalable Poducts. Ntogen Chaactestcs Total Ntogen Ntogen Actve ndex (NA) Cold Wate Soluble Ntogen Uea Methylene Duea Dmethylene Tuea Cold Wate nsoluble Ntogen Tmethylene Tetauea Pentamethylene Hexauea Categoy / 2/ Categoy 2 Pecent / Ueafom (Hecules ncopoated and E.. dupont de Nemous & Company nc.) 2/ Msthylene uea (O. M. Scott & Sons) 66

8 Table 5. Salt ndex of Vaous Ntogen Souces. Ntogen Souce % N Salt ndex Equal Weghts /2/ Equal N Levels Sodum Ntate Ammonum Ntate Uea Ammonum Sulfate Methylene Uea / Concentaton of ons n the sol soluton based on sodum ntate at. 2/ Ntogen s mxed wth a ded sol whch s bought to 75% of feld capacty and stoed fo 5 days at 5 C. 67

9 Table 6. Pecent nuy of Meon Kentucky Bluegass as Affected by Soluble and Patally Soluble Ntogen Souces Appled to Wet o Dy Folage/. Analyss % CWN Wet Dy 2/ 3/ Pecent nuy Lbs N/ Sq Feet 2 LX Folage Condton When Appled Wet Dy Wet Dy Aveage Wet Dy / Waddngton, Duch and Mobeg, Lawn Fetlze Test Pogess Repot 296, June 969. The Pennsylvana State Unvesty, Unvesty Pak, Pem. 2/ Recoded 2 days afte applcaton (August 26, 966). 3/ Temp. 73, 84, 9 F max. and 52, 59 and 53 F mn. on, and 2 days afte teatng, espectvely. Relatve humdty

10 Table 7. ntal and Resdual Colo Response of Kentucky Bluegass as Affected by Vaous Ntogen Souces Appled n Late Fall (/22/77). ntal Response Resdual Response Colo (>l) % # Date of Obsevaton N Souce Categoy CWN N/M 2/ 477 4/9 5/ Methylene Uea * 5.* 5.7* Ueafom * BDU (coase) * Contol LSD.5 NS * Sgnfcant mpovement n colo as compaed to the check (no fetlze) BC 8.2C

11 Table 8. ntal and Resdual Response of Kentucky Bluegass as Affected by Vaous Ntogen Souces Appled n Md Spng (5877). N Souce % CWN #N/M. ntal Response Resdual Response Colo > 5/3 Date of Obsevaton 6/4 7/29 Methylene Uea BDU (coase) Contol

12 Table 9. Fesh Weght of Kentucky Bluegass Clppngs Removed fom a, Sq. Ft. Aea as Affected by Methylene Uea o Uea. Poduct Lbs. N/M Weeks afte Applcaton 4 6 Clppng/, 2 Lbs. of Total Sq. Ft. % Methylene Uea / Uea / Appoxmately /3 less clppngs when tuf s teated wth methylene uea as compaed to uea. 7

13 Table. Fall Geenng Response of Kentucky Bluegass as Affected by Two Methylene Uea Souces (Categoy 2) Appled n Ealy Octobe (/2/78). N Souce % CWN # N/M /7 Colo ( >) Date of Obsevaton /27 /4 /2 Aveage Methylene Uea 36% Methylene Contol Uea 5% BC

14 ; ' ' 46 J/ l CA ) {<t "V NO* fllf ; \T>) ;... ' ; 4~ tte[ ht LKJ R( ). L v 4U " T T tt '.. '... ; 42 [ [ '.. ; ' ' ' \ ' ' ' ' ; ; ' / 4 f / U. * * M \ *\ "/ * J F tf(" l }tf / ' / Rk.B. ]+ ; ct ( T T t 4 } t T T \\ L [ J T 4 fu HH Chuch \V\ ' *.^^V^P V 4 (968) Ammonum S ' ' T\ ' f ' "" ' " "f,.j L L4 * 2 ; lfate;. T 4... ; 4 L L^T ;^ ''^T'; ' ^^^fmm^. ^ ^ ;"]"" ~~,, ; Uea and Methyl e Uea (MU) ^ ; A ' L tl. '" * ' 4 4 '.. hlmf '..UUP LTJtfT"." n J h.4,4.. \~ hhf^ V ;...L. ~h L T 3 Months ^ Fetlze Mate.al$. +.. ~t"44 ^ 4 ^ ^ P..p= H + 4u Ft T , ,. t p LJ ; ' ; ; ~ 4. 5 ' 4 " t h.. m As Affe ctbd > 6 4 \ N. ll 4 «c 4 L. = = s ( T V n TT V t ^... by. me ' 4 ^ 4 n a / n L A \ <V \ t 4 [ == M.SOU J 4Gl 4 ~"T~. t d J N/ d. y C h T n u L Vcll " T Vc U J/ t y v \\c e Su t N T.} M.4..u ] H l ) T

15 t^'s ( X Analyss of the Sol Soluton as Affected by Uea and Methylene Uea Appled at Contol Uea Methylene Uea #N/CY BC

16 ..., ll; Fg T ;3.; Nt ate ; Applec N. at 2 \c tlyss lbsl l } of t /Cul LG s Ya" td Solut.on ; as Af fected by D e a and Mehylene Uea. cn.. ' ' '.., ;.. "4 ' ;. NL/'7* l u JU. ;. t ' ' ;,, LL ;...[,.. ' ; )U ' ' ' ' " f ;. t... ' ;. ' ', ( ; ; ^4+ 4f4 \ f tt ;,.. L J ( f ' ' ; 4 ft L ]4 f ] T l { ;. ' ' 4 ' ] ' l'... ' +, t 4 n / 4 "T.L4...;;44;. L 4 T' HT, f """ f,[ f 4 f ~ J 4 f TO "" t ' h..,44 " T... "]..7 T ". [; ^ ; S m ^... wmm * + *< e " ; [ ' ' f ] T, [ 4 4. t, " h. ;...Lu 44 ""' "T T " t f J } ;J4 M. ; ""h"; ; ; Tf 4 L, 4. p }.... ^ TV ' ' ys ' 4 ". t ' "T" "...,...J] " T ttt PM...p.... Tl,4 ; ;. ' T < L. ; m* m "... L + 4~ k k m m \. V & J ^ ~ b V mm n \ J 4.4. \ " ± M J + L......J e h t 7" 4 en Op ; p. V + 44 J4' fa 4

17 .. ; ; ;. ; ; M ^e^ht d Kentucky ^luegass as A6Eedteed fey tfeea sm& fetfoye?te Uea Appled at N/ Sq. Ft. Contol Uea Methylene Uea ntal Response Resdual Response en Fesh Weght (gns) Fesh Weght (gms) Weeks Afte Teatng Weeks' Afte Teatng BC 5786

18 Fgue 5. Clppng Fesh Weght of Poa patenss Teated wth a 2% CWN Souce (64) 54* Expessed as Dffeences fom Tuf Teated wth a 42% CWN Souce (2377)/ /25/65 Cuttng Numbe A Fetlze Appled at lbs ntogen/ sq. ft. * Sgnfcantly dffeent fom 2377 at the 5% level /Waddngton, Duch Mobeg, Lawn Fetlze Test Pogess lepot The Pennsylvana State Unvesty, Unvesty Pak, Penn.

19 X TO THE VH KEUFEL & ESLR CO. Fgue 6. Colo of Poa patenss Teated wth a 2% CWN Souce (64) Expessed ^ teated wth 42% CWN Souce (2377) / f) 5/25/65 ;, Cuttng Numbe A Fetlze appled at lb N/ sq. ft. * Sgnfcantly dffeent fom 2377 at the 5% level / Waddngton, Duch Mobeg, Lawn Fetlze Test, Pogess Repot 296, June 969v The Pennsylvana State Unvesty, Unvesty Pak, Penn.... J