M > rl a H U. a. C -H O -H. eg o. f 4. o <«1 *J 1. 4J t0 1. s j H -H 1 C 13. > c 1 O 4J H M 1

Transcription

1 m 4-> 4-> M c it) cn cn 1 rh ft z «S -H >1» M c e -H.* <g <j U eg O- c >1 23 S3 r 41 X> eg a. C -H S? eg O -H rl a M > f 4 U H U c m O 1 c - e -H M hi xi «J Si r JS U I c m: u M 3 O HI c H 13 vw C W rh a HI --I X. H C UJ 1 4J 1 -H 1 4J H O 1 w u 1 a, «1 > < 14 - a O 4J H 4J t 1 *J 1 <a s j > c 1 H -H 1 <«1 M 1 1 C 13 ~H itj M H 3 O >4 en cnr^mrof^rrt^cri^rc^rrrrr^rn^ n m ^r r ««t»v9^v5.r^<nh«va)c^^«uiinr^v5vvwui(n^ma>. ^r<^r^rihoivdf^rr^<nvrnrhc<sir^«f^^i^t^r^ nrmnmn<n^rtri^^m<rrmrm<nrmrni^rt^mnnm rti^mim^n,«i,(nf^n,n,fow«n,f'. r- CM m ft v 5P r- cn CO cn p- ft rh ap CM VO en ft CM rh O rh m -ap v T *p en p- en rh in en 5P VO en cn en rh en en in O CM *ap «P rh O p» SP <M 5P VO v cn m en rh in T v m m p- CM in en in c in c in en en en ft rh CM P- en en m CM m en m in rh CM VO P- m p- in en m v v VO CM en m SP m ft m CM t- CM rh CO v p- v VO 1- v m rh in in ft P- en in VO p- m in m VO fa rh P- VO CO in in ap 1- -P rh P- P» VO I rh CM O O O O O O I O O O O O O I rh CM CM CM I ft rh CM CM O O O O I O O I ft rh O O O O O I O O O O O O I CM CM CM CM I O O rh rh CM CM O ft CM O O O O O O O O O O rh CM CM CM I O O O O I I rh rh CM CM I I ft rh ft CM O O O O 1 1 O O O O O O 1 1 O CM CM CM CM 1 1 rh CM I I I I I I t I t I t I e l l z I Z l z I Z I 1 I Z I t z I I I I I c I c i t I I Z I Z I Z I I I I t I I Z I t z t z t z t 2 t I t I t Z I 2 I Z I t I Z I I I I I I t I t I t I t i z i z i z i z v en M «O C H pa in SB aj X ap p- m 1 a aocoaocooocovovo-ap-ap-ap-ap-ap-apadaocococooovovo-ap-apaap *7COaOCOCDv*)COVVC>ara,*al-a'-]>-TQ]aiaOCOCOa)^VCl'f-a<af-r'Jar rhrhcncmcncncmcn rhrhcmcmcmcncncm rhrhcmimemcmcmcn -' H H N fm N (M CMCM

2 52 Table 7. Influence f N-rate, K-rate and nitrificatin inhibitrs n stver and grain N cntent and ttal N remval n fur crn hybrids at physilgical maturity. Becker, MN 1. N-Cncentratin N-Remval #/A Hybrid Inh. K-Rate #/A Stver Grain Stver Grain Tta #/A Pineer 3737 LH74 X LH85 DeKalb

3 53 Table B. Cntinued frm table 1. # K-Rate nly ( Hybrid X X ) Hybrids Pineer 3737 LH74 X LH85 DeKalb 485 Nne N-Serve Hybrid X Hybrid X X Hybrid X X Inh. Whle Plant Silking Stver T/A % N»/A Split Plt withut the * K-Rate 1 Hybrid X X Hybrid Pineer 3737 LH74 X LH85 DeKalb 485 BLSD(.5) Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X K-Rate X K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X X K-Rate

4 54 Table 9. Cntinued frm table 2. Milk Stage R3 f K-Rate nly RCB ( Hybrid X X Inh.) Hybrids Pineer 3737 LH74 X LH85 DeKalb 485 Grain Dry Matter Prductin Yields Grain Stver Cb Tta Bu/A S Nne N-Serve Hybrid X Hybrid X X Hybrid X X Inh Split Plt withut the * K-Rate 1 BLSD(.5) Hybrid X X Hybrid Pineer 3737 LH74 X LH85 DeKalb Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X X K-Rate K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X X K-Rate

5 55 Table 1. Cntinued frm tabic 3. Milk Stage R3» K-Rate nly RCB ( Hybrid X X Inh.) Hybrids Pineer 3737 LH74 X LH8S DeKalb 485 Nne N-Serve Hybrid X Hybrid X X Hybrid X X Inh. N-Cntratin Stver Grain Cb Stver N-Remval Grain »/A- Cb Ttal SO Split Plt withut the * K-Rate 1 Hybrid X X Hybrid Pineer 3737 LH74 X LH85 DeKalb 485 Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X X K-Rate K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X X K-Rate

6 56 Table 11. Cntinued frm table 4. Dent Stage R5 I K-Rate nly RCB ( Hybrid X X Inh.) Hybrids Pineer 3737 LH74 X LH85 DeKalb 485 Ilnhlbltr Nne N-Serve Hybrid X Hybrid X X Hybrid X X Inh. Grain Dry Matter Prductin yields Grain Stver Cb Ttal Bu/A Split Plt withut the * K-Rate 1 Hybrid X Hybrid Pineer 3737 LH74 X LH85 DeKalb 485 Nne N-Serve Hybrid X Hybrid X X Hybrid X X X Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X X Hybrid X K-Rate K-Rate X K-Rate X X K-Rate Hybrid X X X K-Rate

7 57 Table 12. Cntinued frm table 5. Dent Stage R5 N-Cncentratln Stver Grain Cb N-Remval Stver Grain Cb Ttal t K-Rate nly RCB ( Hybrid X Hybrid Pineer3615 Pineer 3737 LH74 X LH85 DeKalb 485 Nne N-Serve Hybrid X Hybrid X X Hybrid X X Inh. X Inh.) B Split Plt withut the 8 K-Rate 1 Hybrid X X Hybrid Pineer 3737 LH74 X LH85 DeKalb 485 BLSD(.5) Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X K-Rate X K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X Inh. X K-Rate

8 58 Table 13. Cntinued frm table 6. Physllglal Maturity t K-Rate nly RCB (Hybrid X X Inh) Hybrids Pineer 3737 LH74 X LH85 DeKalb 48S BLSD (.OS) Nne N-Serve Hybrid X Hybrid X X Hybrid X X Inh. Grain Dry Matter Prductin Yields Grain Stver Ttal Bu/A T/A r\ Split Plt withut the S K-Rate 1 BLSDI.5) Hybrid X X Hybrid Pineer 3737 LH74 X LH85 DeKalb 485 BLSDI.5) Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rat X K-Rate Hybrid X X K-Rate X K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X X K-Rate OS n.

9 59 Table 14. Cntinued frm table 7. Physilgical Maturity N-Cncent ratin N-Remval Stver Grain Stver Grain Ttal.» K-Rate nly RCB ( Hybrid X X Inh.) Hybrids Pineer 3737 LH74 X LH85 DeKalb 485 Nne N-Serve Hybrid X Hybrid X X Hybrid X X Inh Split Plt K-Rate 1 Hybrid X X Hybrid Pineer 3737 LH74 X LH85 DeKalb 485 BLSDI.5) Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rate withut the 8 X K-Rate Hybrid X X K-Rate X K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X X K-Rate

10 t c rl 4-> O O 3 en O en rh u. e U M a> t 4J «4J S > e» 8-9 r.3 O -H > a > ) C m O 73 -H C H O XI -H S-i 4J X! O C -H M M O -4 O c evt ffl rh M CO Z 4-> UJ rh n a I 4-1 Z 4J MH - O c HI 3 -H UH c XI Ifl M 4-1 O c > ed O 4a> O. t <B O <*> rh C s H t < Eh VI XI > HTrHOe»vvrHOaap*»cMvr--eni~p-rHrHcDa«pr-inp--3,p-.MrHCM<nrHenenv vincinenr-avcmcmvemt~e»rhen»apvr~encmenp-eminrhinenrhvp-cncn -atanp-p-cp-cncncinanccncncnt^*^*cnorhrhooaaranenctncnrhov apenenvvrhaapvcnrheainra-rhr^inrhinenorh-^earhvcnecmrhpacmencman cnenenenen.tv,*p^cncnenenenenaapinenaapenenin*ap^»-apvvininaap-3'aapvtvin venrhoovrhvoenc»inenrhentnencmccnenenen»-pininp-vcmp-venenrh«aprhinen Trve»cnenrHveMrHr~entnin-»-apvmenrHrHrHO-apineneM*arrHrHcMenp-'<pcM CMCMeMeMeneMeneneneneMenenenenenenfntneneMiMeneneneneneneneneMCMeneMtnenencMenen I l I l I O O I I I O O I I O O I O I l I I O O I O I I O O I I O O I O I rh I rh rh I rh rh I rh I I rh rh I I rh rh I rh I O O I O O I rh rh I O O O I O O I O I rh rh rh IOOI I O O I O O I I O O I rh rh I I rh rh I I I izizizizi CO 1 I CO I CO I I i ItOltOjtOI i i izizizi 1 c l 1 I t W t 1 t 1 1 l t t CO t Z 1 1 z Z 2 Z 1 1 z z z z v en M 4) 4> C u HI 4) C r- X --I X r-l X r-l GOGOOOCOVVOVV GOCOCOCOVOVOvOVO CO CO CO v v v v cavvvv

11 . u <D U «-> > w cn en rh c nj It) O t HI cn -t m ) s H > c (9 cn IT c 4» a c H! H ~-l 4-> 3 K) O H H) UH x: H JJ M 4-> -rl 4-> C ed tn C m rl u ii XI 4-> > eg x; M 1 c it. M O a, O HI 4J M rn 3 M 1 UH z c UH c HI -r s u 3 3 rh T) VM O c M M a -I XI m C O -r( 4-1 XI 3 TJ O u CLi M U 4) a c H eg rl 1 c - r4 rh IT) W H O > U XI X HTHHOa9l^HvftlflUlCftfO-TC.r-i/)(a-g NOHrtffl(-)inNinOHI»aa,Ul(*)IONPHlfl euinapnac^ci<im)-fhoanppriothcan(npihcmvpnaavdn inanvinvvvvvvvanr^r-ap-p-r-apar^pa'ininr^vr->vdr*ar^r^r^an*apvvr*aanvtpai-- esvrhinvenenemeinvrhoeneme»enemot---aprhancmccm>nenccminpaencnvv inaopvdpp.pvop<incdccccapiift«istgv«igu>v9v9in<rpppipspp vaapenrhanrninvtaapvmenenrhrhenenao-ap-atenrhoinemrhvvinvcmencmcm ^arircwupc'ie^inauoincr-oaochaa^-i'pppiohoivth-fitnvinc. cnenenenenenrenenenenen»ap^,-aphp-ap-ap^-apenenataapaap-ataapaapininemene^ ra-inrhvrrjrr^vr^rhenrhenc^vaboaooo^aapenveaaineenvinenien^arcmc ra-vcmenrhenencmenemeinaapcmcmrhrinenenenem<naocvenenenenv-apaap-ap-apen-apa^ rhrhcmrhcmrhcmcmememrhrhcmemcmcmcmcmcmcmrhrhrhrhrhrhrhrhrhrhrhrhcmemcmrhcmememem anintaa-i--ar~emparhinmvr~tncmanrhine»vininrhe»enve»-appaemr TenencNOrHcn-app--apv-aPanvincMr-cr-e~veMrHvr~encMenecnentnin-3"aMp^ r-avcncencciscncncnr-avcncncncncncnintncpapavccaavtnc I I I rh I I I I I I I I I rh rh rh rh rh 1 ft rh 1 1 I ft ft 1 1 ft 1 I 1 rh rh 1 O O 1 O O 1 rh rh rh rh rh 1 1 t z t z t z t z t 1 t Z 1 z 1 t 1 t Z 1 z CO 1 CO Z 1 Z 1 t 1 t Z 1 Z t 1 CO Z 1 Z OT z n <B HI C H a. u HI HI C O in X r-l X f\ X r-l P- X r-. flccvvvv cccuvvvv cccvsvvv acvvvv rh ft ft ft ft f-4 r< ft ft ft ft ft ft ft ft ft

12 Table 17. Influence f N-rate, K-rate and nitrificatin n N cntent and ttal N remval n fur crn hybrids at the milk stage R3. Naseea 1. N-Cncentratin N-Remval Hybrid Inh. K-Rate Stver Grain Cb Stver Grain Cb Ttal #/A #/A S Pineer LH74 X LH LH74 X LH

13 Table 18. Influence f N-rate, K-rate and nitrificatin n grain yield and dry matter prductin n fur crn hybrids at the dent stage R5. Waseca 1. Grain Dry Matter Prductin Hybrid Inh. K-Rate Yields Grain Stver Cb Ttal #/A #/A Bu/A Pineer LH74 X LH LH74 X LH

14 t Table 19. Influence f N-rate, K-rate and nitrificatin n N cntent, and ttal N remval n fur crn hybrids at the dent stage R5. Waseca 1. N-Cncentrat in N-Remval Hybrid Inh. K-Rate Stver Grain Cb Stver Grain Cb Ttal #/A #/A % Pineer LH74 X LH LH74 X LH

15 enenencncdoaaiod enencytcaoocdo enerven^c cncnenenccdcc OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO t-1 X X t-1 X CD X vn Z I Z CO I CO z t Z I CO I I z t Z I Z I CO I CO I z CO z CO z CO z I Z I z t I cn l c I I z CO I I I I I I I I I I O O I I O O I H H" I O O I O O I f' I f- r-> O I O I I r-> I-- I I r-> I H h-1 I I I O O I I O I O O I I I O O I I O I O O I I >- M I O O I O O I I r- I I O I I O I \^^^t^^t^ftf»f*t^f^f^ftf*f^fif*f»f*f*f*fif»f*t^ftfiftf,ftftfmf*f4f*ftftf*ftf* af*.cn.i-.tj1ala..l-k.tetj1r-'r-'tnaotnt^va>a/1.ea.cjlr--rj alposlbaauuh-.isiailoolocohiooa.-^-lalaeaofralhucoavvvcoua.lw^a'lco»jcdhn}<j-'hchhcoodholdaoidha4voiajcrtc^fftldhaajuvohcou)\ulanl\}nuiio aou)aoululaovowmn)vovouuvoaouun)naowaoulou)ulouwuiuuw &CD<jt\&u>^<jt^&\^<Jt(?>tv<jivi<jt^^&m^^<jta>(ji<BtA>t<ritDa\'Jtjj<,j*j±ta> tdwov1nvutooa u1ajv&aj^wajhn)to<oooaj SalN)tOIOIOlvvavllOv,lrla]tC> uiuuuiuuu)uiuiuja.uuuuuiuuuuii»uiuuuuu)uuuuiwuuuuuwuu ancoca-.avtoxi&hlgoioa4taoacaiaiuia1caa.aj D-JaJCOOII4FOOOIV>4.HHUH tdautuucnr-1vcnro-i^uicnodrha>vvatr.cntrjcnaajcntnri-^ al-al-jajcftcac^-jolanaajajajajfnajajao-ncilaoajajajajajajajagc^tftajc^ 9iPOalA»OOCvlSaJWUOe>NMH9IUHUa4lvUiN)»elHeAI>nOUIUlUe ajc^uvogolajn}ajv9ohmlon)k)aaacc^anv.o-%o4.ann)n)ajvaidnjmiaeaa u K C. r- r fl> ) r- a M M 1 B> < 1 r" 1 3 K I n> 1 ct ct 1 CO If 1 it n H v < t) > O H n a c -3 rt 1 H- 1 rt ) s -5 CV cr 1 3 Hi a f- c c. n 8) i-r 3 r- O (]> 3 l-h 3 Hi 1 (> PI c. > H ft ID a H K 3 r 3" 1 < ft tr a r H- t a 3 1 a pi 3 ft H- et h 9 H- *< H> a H- H- ft" H rt H- <Q H- 3 s H 3 t 1 ft tu r K et<»< r» cu I-- a s tn t > it 3 a a r-> H VO < v 3. S) et et t-l en Ol f z

16 Table 21. Influence f N-rate, K-rate and nitrificatin n N cntent and ttal N remval n fur crn hybrids at physilgical maturity. Waseca 1. N-Cncentratin N-Remval Hybrid Inh. K-Rate Stver Grain Stver Grain Ttal #/A #/A Pineer LH74 X LH LH74 X LH

17 67 Table 22. Waseca 1 «K-Rate nly RCB ( Hybrid X ) Hybrids Pineer 3475 LH74 X LH51 LH74 X LH82 Hybrid X 1 8 K-Rate nly RCB Pineer 3475 LH74 X LH 51 LH74 X LH82 Hybrid X Split Plt withut the K-Rate 1 Whle Plant Tassllnq Stver % N T/A N-Remval f/a Hybrid X X Hybrid Pineer 3475 LH74 X LH51 LH74 X LH82 Nne N-Serve Hybrid X Hybrid X X Hybrid X X S Hybrid X X Inhlbtr X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X K-Rate X K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X X K-Rate

18 68 Table 23 Waseca 1 Milk Stage R3 Dry Matter Prductin Grain (t K-Rate nly RCB Cb Stvei Grain Ttal Yields Hybrid (Hybrid X ) Bu/A Pineer LH74 X LH LH74 X LH Hybrid X t K-Rate nly RCB Hybrids Pineer S.8 LH74 X LH LH74 X LH Hybrid X Split Plt withut the # N -Rate K-Rate Hybrid X X Hybrid Pineer LH74 X LH LH74 X LH BLSDI.5) Nne N-Serve IS Hybrid X Hybrid X X Inhibiti Hybrid X X S Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X K-Rate 45 ' X K-Rate Hybrid X X K-Rate x Inhibiti X K-Rate Hybrid X X Inh. X K-Rate

19 69 Table 24. Waseca 1 8 K-Rate nly RCB ( Hybrid X ) Hybrids Milk Stage R3 Pineer 3475 LH74 X LH51 LH74 X LH82 Hybrid X 1 8 K-Rate nly RCB Hybrid Pineer 3475 LH74 X LH51 LH74 X LH82 Hybrid X N-Cncentratin Cb Stver Grain B Cb N-Remval Stver Grain Ttal Split Plt withut the 8 K-Rate Hybrid X X Hybrid Pineer 3475 LH74 X LH51 LH74 X LH82 BLSD(.OS) Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X K-Rate X K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X X K-Rate

20 7 Table 25 Waseca 1 Dent Stage R5 Dry Matter Prductin Grain 8 K-Rate nly RCB Cb Stver Grain Ttal Yields Hybrid Bu/A Pineer LH74 X LH LH74 X LH S Hybrid X K-Rate n iy RCB Hybrid Pineer LH74 X LH LH74 X LH Hybrid X Split Plt withut the # K-Rate S Hybrid X X Hybrid Pineer LH74 X LH LH74 X LH BLSD(.5) Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K- Rate Hybrid X K-Rate X K-Rate Hybrid X X K-Rate X K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X Inh. X K-Rate

21 71 Table 26. Waseca 1 8 K-Rate nly RCB ( Hybrid X ) Hybrids Dent Stage RS Pineer 3475 LH74 X LH51 LH74 X LH82 Hybrid X 1 8 K-Rate nly RCB Hybrid Pineer 3475 LH74 X LH51 LH74 X LH82 Hybrid X N-Cncentratin Cb Stver Grain N-Remval :b Stver G:rain Ttal Split Plt withut the 8 K-Rate 1 Hybrid X X Hybrid Pineer 3475 LH74 X LH51 LH74 X LH82 Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X K-Rate X K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X X K-Rate

22 72 Table 27 Waseca 1 Physilgical Maturity 8 K-Rate nly RCB Hybrid Pineer 3475 LH74 X LH51 LH74 X LH82 Hybrid X 1 8 K-Rate nly RCB Hybrid Pineer 3475 LH74 X LH51 LH74 X LH82 Hybrid X Dry Matter Prductin Cb Stver Grain Ttal -T/a Grain Yields Bu/A S Split Plt withut the i K-Rate 1 Hybrid X X Hybrid Pineer 3475 LH74 X LH51 LH74 X LH82 Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X K-Rate X Hybrid X K-Rate X K-Rate X X K-Rate Hybrid X X X K-Rate

23 73 Table 28. Waseca 1 8 K-Rate nly RCB ( Hybrid X ) Hybrids Physilgical Maturity Pineer 3475 LH74 X LH51 LH74 X LH82 Hybrid X 1 8 K-Rate nly RCB Hybrid Pineer 3475 LH74 X LH51 LH74 X LI182 Hybrid X N-Cncentratln Stver Grain %_ N-Remval Stver Grain Ttal 8/A Split Plt withut the 8 K-Rate Hybrid X X Hybrid Pineer 3475 LH74 X LH51 LH74 X LH82 BLSDI.5) Nne N-Serve Hybrid X Hybrid X X Hybrid X X Hybrid X X X K-Rate Hybrid X K-Rate X K-Rate Hybrid X X K-Rate X K-Rate Hybrid X X K-Rate X X K-Rate Hybrid X X X K-Rate

24 7«. 1 WEATHER DATA NORTHWEST EXPERIMENT STATION, CROOKSTON, MN T.E. Cymbaluk1 The drught cntinues. Mther nature still has nt cperated with the amunt f precipitatin that is needed. Seven mnths in 1 were belw average in precipitatin. 1 received a ttal f inches, fur inches less than the 1 year average. The small grain seasn, (May 1 - July 31), received 6.98 inches f precipitatin, 2.15 inches belw nrmal. The sugarbeet seasn (May 1 - September 31), received 1.9 inches f precipitatin, 3.29 inches less than the 1 year average. The mnths f May and July recieved less than 25 percent f their nrmal rain fall. In the last seven years, since 1984, there has been a deficit f inches f precipitatin when cmpared t the 1 year average. The last three years, since 1988, there has been a deficit f inches f precipitatin. The greatest amunt f precipitatin that ccurred in a single day in 1 was 2.33 inches n June 1. Seven mnths in 1 were belw nrmal in regard t temperature. The average temperature fr 1 was 41.14T, 1.66" higher than the 1 year average. January, Febuary, and March were well abve the average temperature and December was well belw the average temperature. The highest tempera ture in 1 ccurred n August 16 at 94 F. The cldest temperature was -38 F which ccurred n December 25 and 26. The last frst f the spring was n May 17, 1 (3 F) which initiated a 127 day frst-free perid ending n September 22 (25 F). The grund frst depth reached 37.5 inches n March 15. The grund frst started t thaw n March 3 and by April 25 the grund frst was gne. Table 1. Weather summary fr 1 with 1-year averages precipitatin and mean temperature. Mnth Precipitatin Mean Temperature F January Febuary March April May June July August September Octber Nvember December S Ttal Junir Scientist, Nrthwest Experiment Statin, University f Minnesta, Crkstn, MN.

25 75 Table 2. Recrds brken r matched at the Nrthwest Experiment Statin, Crlcstn, MN In 1. Highest Maximum Temperature Lwest Maximum Temperature Date Old Recrd New (1) Date Old Recrd New (1) January 6 January 1 March 1 March 9 March 1 March 11 April 23 September 24 Octber 26 Octber 31 Nvember 1 December 8 4 (1984) 44 (1958) 47 (1918) 5 (192) 5 (1977) 53 (192) 83 (1942) 83 (193) 76 (1989) 69 (195) 66 (1978) 45 (1939) April 11 April 28 December 21 December 22 December (1951) 6 34 (195) (1989) (1945) (1934) -16 December 9 51 (1939) 56 Lwest Minimum Temperature Highest Minimum Temperature Date Old Recrd New (1) Date Old Recrd New (1) May 9 22 (1945) 22 January (1983) 22 Octber 11 December 25 December (1893) (1933) (1933) -38 March 11 April 23 April (1977) (1957) (19) 59 Octber (1948) 45 Nvember 2 35 (1962) 44 Greatest amunt f precipitatin in a single day. Date Old Recrd New (1) Inches June (1969) 2.33

26 76 DIRECT COMPARISON OF DEEP NITRATE-N LEVELS AND OPTIMUM N FERTILIZER RATE Jhn A. Lamb!' Cnsiderable infrmatin has been btained n the ptimum N rate t use n sil where sil nitrate-n tests are greater than 4 punds per acre in the 2 t 4 ft depth. Mst recmmendatins cncur that -9 punds N per acre are needed t ensure adequate early seasn grwth. A direct, side-by-side cmparisn between a high subsil nitrate-n and lw subsil nitrate-n sil has nt been dne. With the use f a deep fertilizer injectr built at the Nrthwest Experiment Statin, it was pssible t duplicate a high nitrate cnditin within the same experimental site where the lw nitrate cnditin ccurs. This apprach allws a direct and statistically sund methd f measuring the differences in the N respnse f sugarbeet. Materials and Methds; A field trial was cnducted n a Wheatville lam at the Nrthwest Experiment Statin, Crkstn, MN in 1 with tw deep fertilizer treatments f either r 1 punds N per acre injected t a depth f 3 inches in 12 inch Increments in each rw in Octber Surface bradcast treatments f, 4, 6, and 12 punds N per acre were applied and incrprated at the same time. The initial -2 feet nitrate-n sil test was 6 lb. N per acre and 18 lb. N per acre at the 2 t 4 ft depth. Fur replicatins with a randmized cmplete blck design was used. KW 1745 was planted April 23, 1 frze, and replanted May 11. The plts were verplanted and thinned back t 125 plants per 1 feet f rw. Petile samples fr nitrate-n determinatin were taken July 24, August 21, and September 2. Sugarbeet tps were sampled at harvest with yield and ttal N cntent determined later. Rt quality was determined at American Crystal Sugar Cmpany's Quality lab in East Grand Frks, MN where the brei was sampled. Ttal N cntent f the brei was determined later. Results and Discussin; Rt yield and recverable sucrse per acre was nt significantly effected by the either deep N r surface N applicatins, Table 1. The placement f N at 3 inches did reduce the sucrse cncentratin and recverable sucrse per tn by.7 % and 15 punds per tn, Table 1. The dry seasn influenced the lack f respnse t N fertilizer. Other than as a result f May and June precipitatin there was very little grwth and actually the yield level achieved was surprising. i' Assciate Prfessr, Sil Science Dept., University f Minnesta, St. Paul, MN

27 77 Table 1. Rt yield, sucrse cncentratin, recverable sucrse per acre, and recverable sucrse per tn fr deep N applicatin study, 1 NWES. Rt Sucrse Recverable Deep N N Rate Yield Cne. Sucrse lb/a lb/a T/A% % lb/a lb/t Statistic Analyses Deep N N Rate Linear Quadratic Deep N X N Rate C.V. % is significant at the.1 level. The reductin in recverable sucrse per tn can be attributed t the increase in amin-n cncentratin by the deep N treatment, Table 2. The use f surface N als significantly increased amin-n and tended t increase K cncentratins, Table 2. Sdium (Na) was nt effected by any treatment. Surface N applicatin increased the lss t mlasses.31 % which under the current quality payment system wuld directly effect the ecnmic return. Deep N als increased the lss t mlasses but nly.1 %. in 1 at NWES the ptimum N applicatin fr bth and 1 punds N per acre deep N treatments was punds N per acre. Hpefully in the future this study will be cnduct under mre ptimum cnditins in which mre useful infrmatin can be btained.

28 p < rls If? (ft t; t Cal * O U1 a. i 3 a r-» ( r«vo a _ tu 3 z 8 xft " r- z Z O CD? rt O Z 2? rt (ft Z Z z z z CO CO CO CO t z z c c z z c t + Z» * CO»» Z Z» * + c c»» + c CT 1 rt r- CO rt r- < 1 Ma. M CO A M CO -> t cn en» in u h v t -j -& m c -a) l*> O f> t i i i cn en v ~j O H 8\ A Ul Ul OI A OI OUH A til W W t m h t to N> t t r-> l-» to to r-> to r-> O VO O O O v v r-» O VO O ex> en CO J-> 1. VO VO VO en t r-> H-JHOI r-> en N m -j m -at. i i -J cn en i -j cn -j cn -J en en -j -j O tal i -. u «J -aj VO r-» UMOM OI CD in cn t c en v a> cn -J ui u cn -J v v -J at. a_ LO O CD «J OI O UI -s. Ol t: * cr id K Sat? 1 It u -3 CD cr rt» z 1 3 Oi a II) t rt 1 CD t l-l 8- > 3 1 rt IS rt * z z 1 z c

29 79 PRIMARY TILLAGE EFFECTS ON SOIL SUSCEPTIBILITY TO EROSION AFTER SUGARBEET HARVEST Jhn A. Lambi' After sugarbeet harvest the sil is expsed t pssible wind ersin. There are tw strategies that can reduce susceptibility t ersin: residue and sil rughness management. Tillage affects bth f these management strategies. Use f the crrect tillage tl can increase the amunt f residue left n the sil surface, (sugarbeet tps) by "unburylng" the tps and at the same time leaving the surface in a rugher cnditins. In fall 1989 a study was started with the bjective t determine if there is an ptimal primary tillage peratin after sugarbeet prductin that will minimize sil ersin and nt reduce crp prductin the fllwing year. Materials and Methds: A study was cnducted after sugarbeet harvest in 1989 n a Farg sllty clay sil at the Nrthwest Experiment Statin. Five primary tillage treatments were implemented Octber 11, 1989 after sugarbeet harvest: 1) mldbard plw, 2) chisel plw (twisted shanks), 3) field cultivatr, 4) disk, and 5) n tillage. Percent grund cver was measured Octber 17, 1989, April 18, 1 (befre fertilizatin), and April 25, 1 (after planting). Dry aggregate distributins were nly measured Octber 17, 1989, and April 19, 1. Nitrgen fertilizer was applied accrding t sil test recmendatins and Incrprated with a multiweeder April 2, 1. Marshall spring wheat was planted April 23, 1 with a cnventinal duble disk press wheel drill. Grain yields were taken August 1, 1. Results and Discussin: There was a significant difference in grund cver as effected by primary tillage n all three measured dates, table 1. On the Octber date, after sugarbeet harvest, the sils which were treated with a field cultivatr and light tandem disk had the mst cver, 29 %, fllwed by chisel and n tillage, 2 and 21 %, and plwed sils having the least cver, 4 %. The amunts measured early spring befre tillage had similar differences with small cverage reductins ver the winter. After planting, April 25, 1, the sils treated with a field cultivatr, disk, and n tillage maintained 19 % cverage; chisel, 14 %, and plw, 3 %. This suggests that a shallw tillage peratin such as with a field cultivatr r disk will prvide mre wind prtectin than n tillage at all. The gemetric mean diameter (GMD) is a measurement f sil clddiness. Aggregate (clds) with a size f.84 mm and greater are cnsidered t be nnerdible. The greater the GMD is the less erdlble a sil is. The data suggests that plwed sil has cnsiderably greater GMD than the ther treated sils n bth dates measured. There is n significant difference ccured between the sils treated with the ther fur primary tillages. Grain yield is reprted n a 13.5 % basis in table 1. different tillage treatments. There were n significances In yields frm the In the future it is planned t d similar studies n different sil textures. Table 1. Grund cver, gemetric mean diameter, grain yield, and grain prtein as effected by primary tillage n a Farg silty clay at NWES. Gemetric Grund Cver Mean Diameter Grain Grain Primary 1/17/89 4/18/9 4/25/9 1/17/89 4/19/9 Yield Prtein Tillage % mm bu/a % Plw stse lt24 57i IT79 Chisel Field Cult Disk N Tillage LSD Assciate Prfessr, Sil Science Dept., University f Minnesta, St. Paul, MN

30 NITROGEN EFFECTS ON QUALITY OF SELECTED SUGARBEET VARIETIES J.A. Lamb and L.J. Smithl' During the recent drught years the amunt f residual sil nitrate-n has risen and caused prblems with maintaining sugarbeet quality. One pssible management practice is t select a lw impurity variety. Mst varietal develpment ccurs under mre ptimum sil N cnditins. The bjective f this study is t determine a lw impurity variety will cntinue t be a lw impurity variety at elevated sil nitrate-n levels and if that wuld be mre cst effective management decisin cmpared t average varieties under these cnditins. Three lcatins were used in 1, Nrthwest Experiment Statin (NWES), near Casseltn, ND (CASS), and near Bird Island, MN (SOMN). The treatments were five varieties with the fllwing characteristics, 1.) lw Amin-N (LAN), 2.) lw K, Na, and Amin-N (LKNAN), 3.) high K, Na, and Amin-N (NKNAN), 4.) small tp grwth (ST), and 5.) large tp grwth <LT), with tw N levels (sil nitrate-n - 2 ft + fertilizer), f 1 and 3 punds per acre at NWES and CASS and 84 and 211 punds per acre at SOMN. The study was a split plt design with fur replicatins. Nitrgen levels were the main plts with varieties as the subplt. The subplt size was 14.7 ft (8 rws) wide and 35 ft lng. The plts were planted May 3, May 4, and May 9, 1 at NWES, Cass, and SOMN, respectively. Sugarbeet seed was verplanted and thinned t 125 plants per 1 feet f rw. Petile samples were taken three times during the perid f July thrugh harvest. Harvest ccurred n September 2, September 27, and September 25, 1 at NWES, CASS, and SOMN, respectively. At harvest the tps and rts were sampled fr ttal N analyses alng with rt yield and quality. Quality was determined at the American Crystal Sugar Tare Lab in East Grand Frks, MN. Results and Discussin: Rt yield and sucrse cncentratin are listed in table 1. Rt yield ver the three lcatins was increased 2.4 tns per acre when the N level was increased. The varieties rt yields were different and the ranking frm least t greatest was different at each lcatin. Sucrse cncentratin was nt affected at SOMN and NWES by the treatments. At CASS, there was an interactin between N level and variety. The varieties' sucrse cncentratin were effected differently by the additin f N. At the lwer N level the LAN, HKNAN, and ST varities had the greatest sucrse. At the greater N level the LT variety had the greatest sucrse cncentratin. Table 2 lists the means and statistics fr recverable sucrse per acre, recverable sucrse per tn, and lss t mlasses. Recverable sucrse per acre and per tn and lss t mlasses were Incnsistant as t the respnse t change f N level by each variety ver lcatins. On the average N increased recverable sucrse per acre and lss t mlasses with added N decreasing recverable sucrse per tn. Table 1. Rt yield and sucrse cncentratin at NWES, CASS, and SOMN lcatins, 1. Rt Yield Sucrse Cne. Variety N Rate NWES CASS SOMN NWES CASS SOMN lb/a - T/A ~- - % LKNAN LAN HKNAN LT ST LKNAN LAN HKNAN LT ST Statistical Analyses NLEVEL VARIETY ** *» * * ++ NLEVEL X VARIETY ++ **, *, and ++ are the.1,.5, and.1 significance levels, respectively. y Assciate Prfessr, Sil Science Dept., University f Minnesta, St. Paul, MN and Superintendent, Nrthwest Experiment Statin, University f Minnesta, Crkstn, MN.

31 81 The rt lmpurties: Na, K, and Amin-N, are listed in table 3. Sdium was affected by variety at all lcatins. At the CASS site the varietal differences were affected by N level. Ptassium was nt affected by treatments at the SOMN site. At NWES there was a significant difference in K caused by variety but n difference caused by N applicatin. At the CASS lcatin the K in the beet rt changed differently depending n the variety. With the LT and LKNAN varieties K was reduced with the additin f N. Rt K was increased with the additin f N fr the LAN, HKNAN, and ST varieties. Rt Amin-N at NWES and SOMN increased with increasing N fertilizatin. At NWES the varieties had significantly different amin-n cncentratins. At SOMN there were n differences in amin-n because f varieties. There was a significant interactin between N level and varieties at CASS fr amin-n. The LT variety actually had a lwer amin-n cncentratin when N was applied while the ther varieties had greater amin-n. Table 2. Recverable sucrse per acre, recverable sucrse per tn, and lss t mlasses at NWES, CASS, and SOMN, 1. Recverable Sucrse Lss t Mlasses Variety N Rate NWES CASS SOMN NWES CASS SOMN NWES CASS SOMN *~ lb/a lb/a lb/t.- % LKNAN # LAN 'loo HKNAN LT ST LKNAN LAN HKNAN LT ST Statistical Analyses #* Tk * * NLEVEL ** * ** VARIETY ++ NLEVEL X VARIETY * ++ ** ** ', and ++ are the.1,.5, and.1 significance levels, respectively. Table 3. Rt impurities at NWES, CASS, and SOMN, 1. Variety N Rate lb/a NWES Na K Amin-N CASS SOMN NWES CASS SOMN NWES CASS SOMN ppm - ppm - ppm LKNAN LAN HKNAN LT ST LKNAN LAN HKNAN LT ST Statistical Analyses NLEVEL ++ ** ** * VARIETY ++ ** * NLEVEL X VARIETY «* * **, *, and ++ are the.1,.5, and.1 significance levels, respectively. *

32 82 In summary, ne years results des nt shw any clear trend as t whether a variety that has lwer impurities under nrmal sil nitrate-n cnditins will prefrm similarly under high sil nitrate-n cnditins. I wuld like t thank Allan Cattanach and NDSU crew, and Stan Prksch fr their cperatin and help with the CASS and SOMN lcatins.

33 83 BRIGHT SUN ON SPRING WHEAT AND SUGARBEET J. A. Lamb and T. E. Cymbaluki' Tw studies were cnducted In 1 at the Nrthwest Experiment Statin, Crkstn, MN t evaluate the use f Bright Sun, a fliar tpdress prduct n spring wheat and sugarbeet. Bth studies were cnducted n a Wheatville lam. Spring Wheat The treatments were a factrial cmbinatin f three sil N levels; 5, 1, and ISO punds f sil nitrate-n t 2 feet plus fertilizer N, and with and withut Bright Sun. The fertilizer fr the sil N treatments was applied as Urea ( ) April 18, 1 and incrprated with and multiweeder. The spring wheat variety, Marshall, was planted at a rate f 1 punds f seed per acre n April 18, 1. The experiment had fur replicatins and was in a randmized cmplete blck design. Ppulatin measurements were taken befre tillering. The Bright Sun was applied at a rate f three gallns per acre with a ttal carrier, water, f 15 gallns per acre n June 14, 22, and July 1, 1. The fllwing measurements were taken at sft dugh; frage yield, height, head number, heads per plant, and seeds per plant. The wheat was machine harvested August 1, 1. At harvest grain yield (crrected t 13.5 % misture), bushel weight, and grain prtein (crrected t 13.5 % misture) were determined. Results and Discussin; The grwing seasn in 1 was a cntinuatin f the drughts f 1988 and The subsil misture was depleted at the start f the grwing seasn and nly seven inches f precipitatin fell during the grwing seasn which is 3.3 Inches less than the 1 year average. The use f Bright Sun did nt effect any f the parameters measured (Tables 1 and 2). The use f N fertilizer did increase plant height, heads per plant, seeds per plant, grain yield, grain prtein, and frage yield. Sil N decreased bushel weight. Plant ppulatin was greatest at the 1 lb N/A rate with wheat treated with 5 the 15 lb N/A having less ppulatin. Table 1. The effect f sil N level and Bright Sun n ppulatin, height, heads per acre, heads per plant, and seeds per plant at NWES in 1. Bright Plant Plant Heads Heads Seeds Sil N Sun height ppulatin per acre per plant per plant lb/a in plant/a #/A #/plant #/plant 5 N Yes N Yes N Yes N Yes Statistical Analyses Sil N ** ++ ** ++ Bright Sun SN X BS C.V. % **, and ++ are.1 and.1 significance levels, respectively i' Assciate Prfessr f Sil Science Dept., University f Minnesta, St. Paul, MN and Junir Scientist, Nrthwest Experiment Statin, University f Minnesta, Crkstn, MN.

34 8-. Table 2. The effect f sil N level and Bright Sun n grain yield, yield at NWES in 1. bushel weight, grain prtein, and frage Bright Grain Bushel Grain Frage Sil N Sun Yield Weight Prtein Yield lb/a bu/a lb/bu % lb/a SO N Yes N Yes N Yes N Yes Statistical Analyses Sil N * ** ** ** Bright Sun SN X BS C.V. % ** and * are.1 and.5 significance levels, respectively. Sugarbeets: Similar treatments were used in the sugarbeet trial as the spring wheat trial. The sil N levels were 6, 11, lb N/A as sil nltrate-n, t 2 feet plus fertilizer N applied as urea (46--) n May 2, 1. The sugarbeet variety KW 1745 was verplanted May 2, 1 and thinned t a stand f 125 beets per 1 ft f 22 inch wide rws. As with the spring wheat, Bright Sun was applied at a rate f three gallns per acre with a ttal carrier, water, f 15 gallns per acre n June 22, July 13, and August 3, 1. The rts were machine harvested September 2, 1 and quality samples taken at that time. The quality parameters were determined in the American Crystal Sugar Cmpany's Tare Lab in East Grand Frks, MN. Results and Discussin: Similar t the spring wheat, the applicatin f Bright Sun did nt effect any parameters measured in this trial. The sil N treatment increased rt yield, recverable sucrse per acre, sucrse lss per acre, rt K cncentratin, and lss f mlasses, (Tables 3 and 4). Summary: yield, In 1 at the Nrthwest Experiment Statin, the applicatin f Bright Sun did nt effect the grwth, r quality f spring wheat r sugarbeet.

35 85 Table 3. The effect f sil N level and Bright Sun n rt yield, sucrse, recverable sucrse per acre, recverable sucrse per tn prcessed, and sucrse lss per acre at NWES in 1. Bright Rt Recverable Sucrse Sil N Sun Yield Sucrse Sucrse Lss lb/a T/A % lb/a lb/t lb/a 6 N Yes N Yes N Yes N Yes Statistical Analyses Sil N * ++ ** Bright Sun SN X BS c.v. % **, *, and ++ are.1,.5, and.1 significance levels, respectively. Table 4. The effect f sil N level and Bright Sun n impurity index, rt Na, rt K, rt amin-n, and lss t mlasses at NWES in 1. Bright Impurity Lss t Sil N Sun Index Na K Amin-N Mlasses lb/a ppm ppm ppm % 6 N Yes N Yes N Yes N Yes Statistical Analyses Sil N * ++ Bright Sun SN X BS C.V. % * and ++ are.5 and.1 significance levels, respectively.

36 86 RESIDUAL NITROGEN STUDY AT LAMBERTON1 D.J. Fuchs and W.W. Nelsn2 Abatxaesb: Crn and sybean yields are usually greater in a rtatin than in a mnculture system. This study was cnducted t determine the nitrgen-rate respnse f crn and the ensuing year effect f residual nitrgen n sybean yields. The effect f 6 N-rates ( - 4 lbs/ac) were examined in a crn-sybean rtatin n a Nrtnania lam. In 1, as in all previus years, excluding 1988, N-rate respnse was nted fr crn but nt fr sybeans. In 1, as in all previus years, excluding 1989, sybean yields shwed n significant psitive N-rate respnse frm increasing nitrgen rates applied n the previus crn crp. Crn yields demnstrated a nn-linear respnse t Increasing N-rates, characteristic f a diminishing return relatinship. n (Annual reprt f this experiment has been included in past University f Minnesta, Sil Science Department's "Blue Bk", and much f the previus data will nt be repeated here. 1 was the final year f this study.) Intrductin: The sybean plant has the ability t prduce its wn nitrgen fr plant grwth and develpment via rhizbium bacteria activity. Hwever, the symbitic bacteria may nt be able t prvide adequate nitrgen fr the sybean plant during the entire grwing seasn. The residual nitrgen in the sil may act like starter fertilizer fr the underdevelped sybean plant. Als, the sil nitrgen may be used during sybean seed fill when the ndules becme inactive. If nitrgen is belw the zne f symbitic activity (apprximately 9-12 inches) it will nt inhibit N fixatin and may be used by the sybean plant later in the grwing seasn while uptaking water at deeper depths. This study was initiated t examine the pssible benefit f increased sybean yields frm nitrgen leftver frm the previus crn crp in a crn-sybean rtatin. Methds & Materials: The experiment was initiated in 1984 n a Nrmania lam. Each plt is 3 by 48 feet with 8 replicatins each arranged in a randmized blck design. In 1984, all 8 blcks were planted in crn. Starting in 1985, half the blcks have been in crn, the ther half in sybeans, alternating each year. The treatments cnsist f six N-rates ranging frm t 4 #/Ac applied side dress as urea during the crn year. Additin management data is given in Table 1. /" >. Results: 1 and six year average crn and sybean yields are given in Table 2. Sil Nitrgen infrmatin is prvided in Tables 3 and 4. Regressin analysis was used t determine if there was a significant effect f nitrgen rate n crn and sybean yields. There was a significant nn-linear relatinship between nitrgen rates and crn yields (see Table 2). Crn yields increased with increasing nitrgen rates until the 15 lbs/ac rate, then the yields began t decline (see Table 2). In the past, crn had a significant respnse t nitrgen each year. The six year average crn yields indicate nly slightly increased yields after the 1 lbs/ac N rate (see Table 2). In 1, there was nt a significant effect n sybean yields frm the residual nitrgen remaining frm the crn plts was the nly year a significant nn-linear relatinship existed between the residual nitrgen rates applied t crn in 1988 (see the 1 Bluebk fr mre infrmatin). Table 3 cntains the sil nitrgen data frm the fall f 1988 fr the, 1, and 4 lbs/ac nitrgen rates at 1 ft increments dwn t 5 feet, and Table 4 cntains sil nitrate data fr the, 1, and 4 lbs/ac nitrgen rates at 1 ft increments dwn t 5 feet fr 1984, 1985, and 1987 (nt previusly published in "Blue Bks"). The ttal nitrgen in the sil is much greater under 4 lbs/ac N rate than the and 1 lbs/ac N rate at all depths (Table 3 and 4). The sil nitrgen frm the 1 lbs/ac N rate fllws the lbs/ac N rate very clsely, except fr the t 1 ft increment fllwing the 1988 drught (Table 3 and 4). Summary; The results frm this study indicate that excessive rates f nitrgen applied t crn in a crn-sybean rtatin des nt have a significant effect n ensuing sybean yields. The 4 lbs/ac f nitrgen rate resulted in much greater sil nitrgen values, whereas the 1 lbs/ac N rate had nly slightly increased levels frm the lbs/ac N rate. The greatest amunt f sil nitrgen ccurred in the upper 2 feet f the prfile. 1 Funding prvided by the Agricultural Experiment Statin. 2 Assistant Scientist and Superintendent - University f Minnesta, Suthwest Experiment Statin, Lambertn, MN 56152, respectively.

37 87 Table 1. 1 Crn and Sybean Management Infrmatin. Item Crn Sybean Sil Test (ppm) PA K-O ph Fall Primary Tillage: Sil Saver Sil Saver Secndary Tillage Type: Date: Digger (Twice) 23 April Disk (Twice) 3 May Seed Hybrid/Variety: Rate: Date: 27,7 ppa 25 April Hardin 15, seeds/ac 4 May Herbicide Brand: Rate: Date: Eradicane-Bladex 2.5 & 1.5 #/ac 23 April Treflan-Sencr.75 &.25 #/ac 3 May Cultivatin Date: 12 & 22 June 11 June & 6 July Table 2. 1 and Six Year (1985-9) Averages f Cm and Sybean Yields (Bu/Ac) Nitrgen (lbs./ac.) 1 Crn 1 Sybeans 6 year Avg. Crn 6 year Avg. Sybeans Table 3. Fall 1988 residual sil nitrgen (ppm) infrmatin. Depth lbs/ac 1 lbs/ac 4 lbs/ac (feet) NH, NO, Ttal N NH4 NO, Ttal N NH, NO, Ttal N

38 88 Table , 1985, and 1987 sil NO, (ppm) Infrmatin fr the, 1, and 4 lbs/ac N rates. Depth (feet)

39 89 TO A THIRTY ONE YEARS OF FIELD EXPERIMENTATION WITH NITROGEN SOURCE, PLACEMENT, AND TIME OF APPLICATION WEBSTER CLAY LOAM AT THE SOUTHWEST EXPERIMENT STATION LAMBERTON, MN1 D.J. Fuchs and W.W. Nelsn* Abstract: Crn yields may be affected by different nitrgen management systems. This study was cnducted t determine if differences exist between nitrgen frms (urea r ammnium nitrate), amunts ranging frm t punds N/Ac, and their time f applicatin (fall, spring r sidedressed) and placement (surface, mldbard plw incrpratin r sidedress) n crn yields. The effects were examined n cntinuus crn with 3-inch rws in a Webster clay lam. In 1, there was little difference between the and punds N/Ac treatments. The 4 punds N/Ac treatments had lwer yields with the check having the lwest yields. The time f applicatin and N frms affected yields as they have in the past 3 years. The 3 year average f the treatments indicate that crn yields respnd the greatest t N rate with a slight advantage t spring applicatin with little difference between N frms. (Annual reprts f this experiment have been included in mst f the University f Minnesta Sil Science Department "Blue Bks" and much f this infrmatin will nt be included here). Intrductin: The Cntinuus Crn Study is a nitrgen fertilizatin experiment invlving varius rates and applicatin times f ammnium nitrate and urea. The experiment has been cnducted since 196 n a tiled Webster clay lam. Methds: The fertilizer treatments have nw been applied annually t the same plt area fr 3 years. Each plt is 2 by 77.5 feet with the fur replicatins arranged in a randmized blck. After ear crn remval and stalk cutting, the fall treatments are bradcast n their respective plts and the entire area is then mldbard plwed t apprximately 12 inches deep. The fall surface treatments are then bradcast with n further wrking f the plw area. Spring treatments are bradcast befre seedbed preparatins in late April r early May. The crn is planted in 3-inch rws at a plant ppulatin f 26, plants/a, using a band starter fertilizer f at a rate f 1#/A ver the entire experimental area, thus supplying an additinal 14 #N/A t all plts. Sidedress treatments are bradcast in June and Incrprated during cultivatin. Results: The 1 yields frm this experiment are given in Table 1. The 3-year yield averages are prvided in Table 2 (In 1976, n yields were btained due t drught, thus nly 3 years f data exist). The ne-way analysis f variance (Table 3) Indicates a significant treatment effect. The LSD fr 1 yield cmparisns (a =.5) is The results f 1, like the results f 1989, did nt cmpletely fllw the trend f the past where greatest yield respnse is t increasing N-rates with applicatin time in the spring. This may have been caused by residual nitrgen that was nt used during the dry 1988 grwing seasn and was available fr use in 1989 and 1. The highest yielding treatments was punds f urea N/Ac fall incrprated (see Table 1). Hwever, there was n significant difference in yields between either frms f N at the and lbs/ac rates, except fr the significantly lwer yielding fall incrprated lbs/ac f ammnium nitrate treatment (see Table 1). This year and in the past, there has been a mderate respnse t delayed applicatin time with the greatest respnse at the 4 lbs/ac N rate. The lng term averages indicate that urea nitrgen treatments had apprximately a 2 bu/ac yield advantage ver ammnium nitrate, nt Including the side dressed ammnium nitrate rate f lbs/ac. This year as in the past, there is little difference in yield between ammnium nitrate and urea treatments. 1 Funding prvided by Agricultural Experiment Statin ' Assistant Scientist and Superintendent - University f Minnesta, Suthwest Experiment Statin, respectively.

40 9 Table 1. 1 Yields (Bu/Ac). Ammnium Nitrate Urea Applicatin Time 4# # # 4# # # Fall (Incrprated) Fall Plwed Surface 123 Spring Side Dress LSD (a =.5) = 15 Bu/Ac Bu/Ac Check 81 Grand Mean 124 Table 2. 3 Year Average Yields (Bu/Ac). Ammnium Nitrate Urea Applicatin Time 4# # # 4* «# Fall (Incrprated) Fall Plwed Surface Spring Side Dress Check Bu/Ac Grand Mean 11 Table 3. One-way analysis f variance. Surce DF Blck 3 Treatment 19 Errr 55 Sum f Squares Mean Square P value

41 91 THE EROSION-PRODUCTIVITY STUDY AT THE SOUTHWEST EXPERIMENT STATION, LAMBERTON, MN1 D.J. Fuchs, M. Llndstrm, and W.w. Nelsn* Abstract: Field data is needed t evaluate crp grwth simulatin mdels. The bjective f this study is t determine the interactive effect f tillage and sil ersin level n crn yields. Cntinuus crn is grwn under cnventinal (fall mldbard plw) r ridge tillage n sites which have been slightly, mderately, r severely erded. In 1, tillage and ersin levels had a significant effect n crn yields (alpha «-».1). The effect f tillage n crn yields has nt been cnsistent. The ridge tillage treatment had the highest yields in 1. The effect f ersin level n crn yields has been cnstant with the higher yields ccurring n the less erded treatments. Crn yields usually decrease with increasing ersin levels fr bth tillages. Intrductin: This experiment is part f RRF prject NC-174, Sil Prductivity and Ersin. The bjectives f this study are "T asses the effect f ersin-mdified sil physical prperties n ptential prductivity f selected sils under rainfed cnditins, with emphasis n evaluatin f physically-based simulatin mdels." The experiment was started in Detailed results frm 1985 and 1986 were presented in the 1987 "Bluebk", and results frm 1987 and 1988 were presented in the 1989 "Bluebk", and 1989 results were presented in the 1 "Bluebk". Methds and Materials: Plts fr this study were lcated in areas f a field which had been slightly, mderately, and severely erded. The sil type fr the slight and mderately erded areas is a Ves (fine-silty, mixed mesic Typic Hapludalf). The sil type n the severely erded area is a Strden (finelamy, mixed (calcareus), mesic Typic Udrthent). Tw tillage systems were used n the field: fall mldbard PLOW and RIDGE-tillage. The field has been in cntinuus crn since the experiment started. Additinal management infrmatin is given in Table 1. The entire study was mldbard plwed in the fall f 1989 because f the visual and measured ptassium deficiency symptms that ccurred in the ridge tillage treatment. Ridges were re-established during the 1 grwing seasn. Summary f results: Grain yields are given in Table 2. Analysis f variance, using a spilt plt design (tillage = whle plts, ersin class = split plts) is furnished in Table 3. In 1, there was a significant difference between mldbard plw and ridge tillage (see Table 2). The ridge tillage treatment averaged bu/ac and the mldbard plw treatment averaged bu/ac ver all ersin levels. The severe ersin class had significantly lwer yields than the mderate and slight ersin class (see Table 2). Least significant differences (LSD's) are prvided. In 1, as in the past, ersin levels affected crn yields with greatest yields ccurring n the least erded areas. Primary tillage effects n yields have nt been cnsistent. In 1, ridge tillage had the highest yield. The ridge tillage plts were plwed in the fall f 1, s actually the cmparisn between tillages is actually a cultivatin technique cmparisn. Therefre tw pssible explanatins fr increased yields in the ridge area are: 1) the ridge cultivatin n 6/21 prvided better misture cnservatin and sil envirnment which resulted in increased plant grwth and yield and/r; 2) the mldbard plw and secndary tillage peratins thrughly mixed the sil liberating sil nutrients that were frmerly unavailable t the plant fr grwth and develpment (recall that the ridge plts had lwer K levels in the earleaves and shwed visual symptms f K deficiency). Acknwledgements: The Suthwest Experiment Statin wuld like t thank the Jhn Deere Cmpany fr prviding the JD 7 Cnservatin ridge tillage. 1Funding prvided by the USDA - CSRS and the Agricultural Experiment Statin... / if-h^^ Sclen4st " U f MN, Suthwest Experiment Statin; Sil Scientist - USDA-ARS. Mrris, MN 56267; Superintendent - f MN, Suthwest Experiment Statin, respectively.

42 92 Table 1. 1 Management Infrmatin. Item.Type- Rate Date Secndary Tillage disk twice 4/2 & 4/21 Insecticide Furadan 1. #/Ac 4/21 Seed 27,7 p/ac» it Herbicides Eradicane 2.5 i/ac 4/24 Bladex 1.5 #/Ac it n Fertilizer Starter N = 14 #/Ac P,4 = 41 #/Ac K, = 15 #/Ac n 4/21 Bradcast N = 125 #/Ac A/19 (Urea) n Mechanical Cultivatin twice 6/1 & 6/21 Weed Cntrl Ridged1 nce 6/21 1/ Bth tillages received the 6/1 cultivatin, and n 6/21 ridge plts were ridged and mldbard plw plts were cultivated. Table 2. Mean yields (bu/ac) f tillage, ersin class and Interactins. Tillage1 Ersin Class' Overall Slight Mderate Severe Mean Plw Ridge Overall I I Mean I / LSD.s = 3.1 fr cmparing tillage treatments (averaged ver all ersin classes). 2/ LSD.s «- 8. fr cmparing ersin classes (averaged ver bth tillage treatments). Table 3. Analysis f Variance. Randmized blck with split plt restrictin Number f: Cases = 24 Blcks = 4 Tillage Levels = 2 Ersin Levels = 3 Surce DF SS MS P-value Blck Tillage ** Whle Plt Errr Ersin ** Interactin Sub-Plt Errr ** significant at alpha =.1

43 93 MANAGEMENT OF SLOPES USING VARIOUS TILLAGES, TILLAGE AND ROW DIRECTION AT THE SOUTHWEST EXPERIMENT STATION1 D.J. Fuchs, M. Lindstrm, and W.W. Nelsn2 Abstract: Field research is needed t evaluate sil mvement under different crp prductin practices and its cnsequent effect n crp grwth. This study was cnducted t examine sil mvement and crp yields n three different slpe percentages (1%, 4%, and 8%), three tillages (ridge tillage, mldbard plw, and chisel), and tillage/planting directins (up and dwn the slpe, r cntur t the slpe) in a crn - sybean rtatin. In 1, tillage had a significant effect n the 4 percent slpes nly with the chisel plw treatment having the highest crn yields. N ther treatments were significant excluding the rw directin by slpe psitin (tp, middle r lwer) treatment. In the past, slpe psitin and/r planting directin als had significant effect n crp yields. (The 1989 University f Minnesta "Blue Bk" cntains infrmatin fr the years 1986, 1 "Blue Bk" cntains infrmatin fr 1989.) 1987 and The Materials: This study began in the spring f 1985 t examine sil mvement n three different slpe percentages (1%, 4%, and 8%), using varius tillages (ridge tillage, mldbard plw, and chisel), and tillage/planting directins (up and dwn the slpe, r cntur t the slpe) in a crn and sybean rtatin. The slpe psitins are nt taken int accunt fr the 4 and 1 percent slpes, and the tillage/planting directins are nt taken int accunt fr the 1 percent slpes. Yields are measured every year. Sil mvement is being mnitred by grass catch strips and infrared transit survey. Additinal management infrmatin is prvided in Table 1. Results: Main effects are presented in tables fllwed by the interactin effects. Analysis f variance fr each slpe treatment is prvided (Table 2-7). The 4% slpe had a significant tillage effect with greatest yields ccurring n the chisel plw treatments (see Table 4B & 5). The effect f tillage treatments n yields have nt been cnsistent (see previus "Blue Bks"). Analysis f variance was nt perfrmed n the different slpe percentages (8, 4 & 1%) hwever, the verall average yield decreased with increasing slpe (see Table 2A, 4A & 6A). Table 1. 1 Management Infrmatin Item Type Rate Date Secndary Tillage1 Digger 2 passes 4/23 Seed 27,7 seeds/ac 4/24 Herbicides Lass 3. lbs/ac 4/27 Bladex 1.5 lbs/ac 4/27 Fertilizer Urea-N N = 13 lbs/ac 6/14 Starter N = 7 lbs/ac 4/24 P,, = 2 lbs/ac KjO «= 7 lbs/ac Cultivatin 6/22 1/ N secndary tillage n ridge tillage plts. 1Funding prvided by the USDA - CSRS and the Agricultural Experiment Statin..' w?,3^^ Scien43t ~ f MN, Suthwest Experiment Statin; Sil Scientist - USDA-ARS. Mrris, MN 56267; Superintendent - U f MN, Suthwest Experiment Statin, respectively.

44 9-. Table 2 (A-H). Crn Yields (bu/ac) n the 8 Percent Slpe. Avg s' Overall n (sample n.) = 54 Oi 2B. Tillage. Tillaqe Avg s Chisel Mldbard Ridqe n = C. Rw Directin. Rw Directin Avg s Up & Dwn Cntur n = 27 2D. Slpe Psitin. 2E. Slpe Psitin Avg s Tp Mid Bttm n = 18 Tillage - Rw Directin Interactin. Tillage Rw Dir. Avg s Chisel Up & Dwn Chisel Cntur Mldbard Up 6 Dwn Mldbard Cntur Ridge Up & Dwn n = 9 Ridge Cntur F. Tillaqe - Slpe Psitin Interactin. Tillaqe Slpe Ps. Avg Chisel Tp Chisel Mid Chisel Bttm Mldbard Tp Mldbard Mid Mldbard Bttm Ridge Tp Ridge Mid Ridge Bttm D s = sample standard deviatin

45 95 2G. Rw Directin - Slpe Psitin Interactin. Rw Dir. Slpe Ps. Avq s Up & Dwn Tp Up t. Dwn Mid Up Dwn Bttm Cntur Tp Cntur Mid Cntur Bttm H. Tillage - Rw Directin - Slpe Psitin Interactin. Till' Rw Dir. SJLpe Ps. Avq s CH Up & Dwn Tp CH Up & Dwn Mid CH Up & Dwn Bttm CH Cntur Tp CH Cntur Mid CH Cntur Bttm MP Up & Dwn Tp MP Up & Dwn Mid MP Up & Dwn Bttm MP Cntur Tp MP Cntur Mid MP Cntur Bttm RT Up & Dwn Tp RT Up & Dwn Mid RT Up & Dwn Bttm RT Cntur Tp RT Cntur Mid RT Cntur Bttm Table 3. Analysis f Variance fr the 6 Percent Slpe. Randmized blck with split - split plt restrictin Number f: Cases - 54 Blcks = 3 Rw Directins = 2 Tillage Levels = 3 Slpe Psitins = 3 Surce DF SS MS P-value Blck Rw Dir Whle Plt Errr Tillage Rw*Tillage Sub-Plt Errr Psitin Rw*Psitin Tillage*Psitin Rw*Till*Ps Sub-Sub Plt Err significant at alpha « Tillage cdes: CH - chisel, RT = ridge tillage, MP = mldbard plw

46 96 Table 4 (A-D). Crn Yields (bu/ac) n the 4 Percent Slpe. 4A. Overall Average. Avg s Overall n = 12 4B. Tillage, (ranked by descending averages), Tillage Avg s Chisel Mldbard Ridge n - 4 LSD.j = 6.8 4C. Rw Directin. Rw Dir. Avq s Up & Dwn Cntur n - 6 4D. Tillage - Rw Directin Interactin. Till Rw Dir. Avg CH Up 6 Dwn CH Cntur MP Up & Dwn MP Cntur RT Up & Dwn RT Cntur r> Randmized blck with split plt restrictin Number f: Cases Tillage Levels = = 12 Blcks = 2 3 Rvr Directins - 2 Surce DF SS MS P-value Blck Rw Dir. Whle Plt Errr Tillage Rw*Tillage Sub-Plt Errr significant at alpha " *.4958

47 97 Table 6 (A-B). Crn Yields (bu/ac) n the 1 Percent Slpe. 6A. Overall Averaqe Avq s Overall n = 6 6B. Tillaqe. Tillaqe Avq s Chisel Mldbard Ridqe Table 7. Analysis f Variance fr the 1 Percent Slpe. Randmized blck Number f: Cases» 6 Blcks = 2 Tillage Levels = 3 Surce DF SS MS P-value Blck Tillage Whle Plt Errr

48 5.2 _ 98 WEST CENTRAL EXPERIMENT STATION WEATHER SUMMARY - 1 n Temperature Sil Temperature 1-yr. Dev. 1-yr. Dev. (1 cm depth) Mnth Perid 1 av. frm av. 1 av. frm av. 1 1 vr. av. January February March April Ttal r av _ May Ttal r av June Ttal r av July / Ttal r av August _ Ttal r av September IS Octber Nvember December April-Aug. Grwing Seasn January-December Annual r>

49 CONTINUOUS CORN SILAGE1 MORRIS, 1 S. D. Evans2 ABSTRACT: This lng-term study addresses the effects f remval f cntinuus crn silage and crn grain n sil prperties and yield. Results after 25 years shw n yield differences due t the remval f silage versus grain. A significant difference in yield exists between the lng-term high and lw fertilizer rates. Oblectlve: This is the 25th year f a cntinuing study initiated in 1965 n a Mcintsh silt lam sil. The study was Initiated t determine the effects f remval f cntinuus crn silage and fertilizer rate n sil prperties and yield. Half the plts receive a fertilizer rate f (N+P,5+K,) lbs./acre and the ther half a rate f Silage and shelled crn yield samples were cllected. Experimental Prcedure: The experiment is set up as a latin square with 4 treatments: (1) silage, lw fertility (2) silage, high fertility (3) grain, lw fertility (4) grain, high fertility. The previus years crn stalks were chpped n Octber 23, The fertilizer was then applied and disked in n Octber 23, The experimental area was mldbard plwed n Octber 24, The study was field cultivated tw times n April 25, 1 fr seedbed preparatin. The study was then seeded t Pineer 3751 crn at 26, seeds/acre n May 4, 1. Furadan 15G was applied in the rw at seeding at 1 lbs./acre (1.5 lbs./acre a.i.). 3 lbs./acre a.i lbs./acre a.i. were applied pre-emergence bradcast m May 4. Date f tasseling and silking was recrded. Silage yields were chpped frm 3 1-ft rws n September 17 and grain yields were calculated frm 2 45-ft rws harvested with a plt cmbine n Octber 2, 1. Yields were als taken, as in past years, n an adjacent unfertilized (check) area where nly the grain is remved. Results and Discussin: Silage yields are given in Table 1. There were n significant differences in silage yields In 1. The 25-year average shws n effect f silage versus grain but des shw significant differences between high and lw fertility treatments. Grain yields, including the grain yield frm the unfertilized check area adjacent t the plts, are given in Table 2. The 1 yields shw n significant difference in grain yield between the high and lw fertility treatments. The lng-term 25 year average des shw a significant grain yield advantage fr high fertility ver lw fertility. This study will be cntinued in 11. Funding prvided by the West Cent. Expt. Sta.. Univ. f Minnesta. Prfessr, Wst Cent. Expt. sta., Univ. f Minnsta.

50 1 Table 1. Effect f remval f cntinuus silage r grain n silage yields. Treatment 1 Yield Yield dry matter, tns/acre Silage, lw fertility Silage, high fertility Grain, lw fertility Grain, high fertility Signif. Levels (%) Treatment Year Treatment x Year LSD, treatment (.5) 73 > >.16 Table 2. Effect f fertilizer level n grain and silage yields. Treatment Grain, lw fertility Grain, high fertility 1 Yield % M Yield Signif. Levels (%) Treatment Year Treatment x Year LSD, treatment (.5) 49 > > 3. Grain, check (Bu/Ac) Silage, check (D.M. Tns/Ac)

51 11 WINTER UREA APPLICATION ON HIGH ph SOILS1 h-s^ MORRIS, 1 S.D. Evans and G.A. Nelsn1 ABSTRACT: A 3-year study designed t recrd the effects f winter applicatin f urea nitrgen n high ph sils fr crn prductin was cmpleted in 1. Applying nitrgen during the winter mnths may help reduce fall and spring wrklads allwing fr timely spring planting, but lsses may ccur due t applicatin f nitrgen n frzen sil and/r n snw. Applying urea nitrgen n frzen sil appears t be as effective as spring applicatins, but applying urea nitrgen n snw appears t result in sme yield lss, althugh there were n significant differences in yield due t time f applicatin. Oblectlve; The nitrgen retentin study was designed t recrd the effects f ff-seasn applicatins f urea nitrgen fr crn prductin. Applying nitrgen fertilizer during nn-crpping times may allw fr mre timely spring planting peratins. The retentin study had fur treatments 1) a check with n nitrgen applicatin 2) nitrgen applied n frzen sil 3) nitrgen applied in mid-winter with at least a 3-inch snw cver, and 4) nitrgen applied in the spring prir t crn planting. This study will determine if nitrgen lss primarily frm vlatilizatin is a prblem with late fall and mid-winter applicatins f urea n high ph sils. Experimental Prcedure; The experimental prcedures fr all years f the study were the same. Sil tests in the fall f 1989 were as fllws: ph=7.8, NaHCO, P»21 lbs./acre, exch. K«lbs./acre,NO,-N (-24 inches) - 56 lbs./acre, and NO,-N (24-48 inches) -93 lbs./acre. The experimental area fr 1 was mldbard plwed Octber 28, 1989 and the plts were staked ut Octber 31, The frzen sil treatment ( Trt. 2) was applied n Nvember 16, The mid-winter treatment (Trt. 3) was applied March 16, 1 with a snw cver depth f 6 inches. The spring treatment ( Trt. 4) was applied April 25, 1. All treatments had 12 lbs./acre nitrgen applied and urea (46--) was the nitrgen surce. The experimental area was field cultivated twice n April 25, immediately after Trt. 4 was applied. The plt area was seeded t Pineer 396 crn at 26, seeds/acre n May 4, /""v 1. Lass 3. lbs./acre a.i. + Bladex 2.2 lbs./acre a.i. were bradcast pre-emergence after crn planting n May 7. The experiment was cultivated n June 14 and June 27, 1. Tasseling and silking dates were recrded and a stand cunt was taken n August 16. Six plants and ears were harvested at the black layer stage f maturity fr ttal nitrgen uptake analysis n September 17. Grain yield, misture, and test weight were recrded at grain harvest n Octber 2, 1. The plts were harvested with a plt cmbine, harvest area was fur 65-ft rws. Results and Discussin, 1; Plant measurements are given in Table 1. N differences were fund between treatments fr tassel date, silking date, plant ppulatin, grain yield, r grain misture. The lack f a significant yield respnse may have been due t the high NO,-N in the inch zne. Results and Discussin, 1987, 1988 and-1: Results frm 1989 have been mitted frm this reprt because high residual sil NO,-N levels frm the previus year resulted in a lack f nitrgen respnse when the check treatment was cmpared t the ther treatments. In 1987, 1988, and 1 there were n significant differences in grain yield due t time f urea nitrgen applicatin (Table 2). The spring treatment was the highest yielding in 1987 and 1, and the frzen sil treatment was the highest yielding in 1988 and the 3-year average. The snw cver treatment yielded abve the check treatment but lwer than the ther treatments in 1987, 1, and the 3-year average. The snw cver treatment yielded abve the spring treatment but belw the frzen sil treatment in It appears that applying urea nitrgen n frzen sil is as gd as a spring applicatin and that an applicatin f urea nitrgen n snw cver results in yield lss, pssibly due t vlatilizatin and/r runff. The abve mentined differences in yield were small and nt significant. High residual sil N,-N levels undubtedly influenced this study in 1988, 1989, and 1. f^s 1 Funding prvided by the West Cent. Expt. Sta., Univ. f Minnesta. * Prfessr and Junir Scientist, West Cent. Expt. Sta., Univ. f Minnesta.

52 56 12 Table 1 Summary <sf plant mea:surements - 1. Tassel Silk Date Date Plant Grain Treatme nt frm 7/1 frm 7/1 Pp. Yield Misture Test wt. 1,'s/ac bu/ac % lbs/bu Check ,,3 Frzen Grund ,.5 Snw Cver ,.3 Spring ,.1 U Signif. Levels: Treatment <%) LSD (.5) i )b,.7 c.v. (%) ,.8 Table 2. Winter urea applicatin study, Mrris grain yield results. Grain Yield Treatment Check Frzen Grund Snw Cver Spring Signif. Level: Treatment (%) LSD (.5) C.V. (%) u <J

53 13 r% EFFECT OF TILLAGE AND SUBSOILING ON SOIL WATER RECHARGE AND CORN YIELDS1 Mrris, 1 S.D. Evans, M.J. Lindstrm, J.F. Mncrief, W.B. Vrhees, and G.A. Nelsn* Abstract: Many prducers are using subsilers t alleviate expected cmpactin due t traffic frm tillage, planting, and harvesting equipment. In the fall f 1988 a study was initiated at the West Central Experiment Statin t study the effects f a ne-time subsiling and its interactin with varius primary tillage systems n subsequent sil cmpactin, sil water recharge, crn grwth, and yield. In the spring f 1989 it was fund that the subsiled areas had a lwer bulk density and a lwer vlumetric misture cntent than nn-subsiled areas. There was a highly significant subsiling by wheeltrack interactin n bth variables. By the fall f 1969 the misture differences disappeared, but the bulk density differences remained. It appeared that wheel traffic frm secndary tillage, planting, cultivating, spraying, and harvesting equipment repacked the sil t its riginal density. There were n effects f tillage r subsiling n crn grain yields in Sil misture samples taken in bth the spring and fall f 1 shwed that subsiling had n effect n vlumetric misture cntent. In the spring f 1 there were n effects frm subsiling n sil bulk density, but in the fall f 1 there was a slight subsiling by depth Interactin effect n bulk density. Hwever, mst sil measurements were n lnger affected by subsiling. Penetrmeter measurements shw large effects f wheel traffic, but very small effects f subsiling, regardless f tillage system. There were n effects f tillage r subsiling n crn grain yields in 1. Based n the results f 2 years f measurements, subsiling did nt increase yields and had n lasting effect n sil bulk density r water cntent. OBJECTIVES: A 3-year study was initiated at the West Central Experiment Statin t study the effects f (ne time) subsiling n subsequent crp grwth, sil cmpactin, and sil misture in 4 primary tillage /""^sterns (fall mldbard plw, fall chisel plw, spring disk, and n-till). The experiment was.tablished n a Hamerly clay lam (Aerie Calciaqull) and Aastad clay lam (Pachic Udic Haplbrll) cmplex and is crpped t cntinuus crn. This reprt will discuss the 2nd year, 1, results f the 3-year study. TILLAGE, PLANTING, and HARVEST PROCEDURES: The experimental plt area was established the fall f The entire plt area was fertilized with a 15 lbs. PtO,/acre and 1 lbs./acre Zn bradcast n Octber 13,1988. Fur main plt treatments were then established in the experimental plt area with each treatment split int subsiled and nn-subsiled subtreatments. A split plt design with 4 replicatins was used with plts 3 feet wide by 1 feet lng. The 1988 crp was crn harvested as silage, and the 1989 crp (1st year f the study) was crn harvested with a cmbine. The plt area was seeded with a 6- rw planter. The treatments are mldbard, subsiled (MSS), mldbard, n subsiling (M), chisel, subsiled (CSS), chisel, n subsiling (C), n-till, subsiled (S), n-till, n subsiling (N), spring disk, subsiled (DSS), and spring disk, n subsiling (D). One-half f each main plt was subsiled n Octber 14, A 5-tth subsiler with a 3-inch tth spacing, perating 16 inches deep, was used n the MSS, CSS, and S treatments. A paraplw, perating 13 inches deep, was used n the DSS treatment. The MSS, CSS, S, and DSS plts were nt tilled with any ther implement in the fall f The nn-subsiled treatments were treated as fllws: (1) The M treatment was plwed using an nland hitch with 6 18-inch bttms and the C treatment was chiseled with a munted 1-ft chisel plw, (2) The MSS and CSS treatments were nt mldbard plwed r chisel plwed befre r after the subsiling peratin in the fall f 1988, and (3) The D and N treatments were nt tilled in the fall Of In the fall f 1989 the plts were treated as fllws: (1) The MSS and M treatments were plwed using an nland hitch with 6 18-inch bttms, (2) The CSS and C treatments were chiseled with a 15-ft pull type chisel plw, and (3) The S, N, DSS, and D treatments were nt tilled. Funds prvidd by West Cnt. Expt. Sta., Univ. f Minncta. Measurements taken /"""S by USDA-ARS, Mrris, MN. 2 S.D. Evans, and G.A. Nelsn are Prfessr and Junir Scientist respectively with the West Cent. Expt. Sta., Univ. f Minnesta. M.J. Lindstrm and W.B. Vrhees are Sil Scientists with the Agricultural Resarch Servlc, USDA, Mrris, MN, and J.F. Mncrief is Assciate Prfessr, Sil Science Dept., Univ. f Minnesta.

54 1-. Crp residue measurements were taken n April 1, 1. On May 9, 1 crn stalks were chpped n the S, N, DSS, and D treatments. On May 11 the MSS, M, CSS, C, DSS, and D treatments were all disked twice fr seedbed preparatin. All wheel traffic frm tractrs during the tillage peratins was cnfined t the psitin t be used by the tractr pulling the crn planter. All subsequent wheel /^*\ traffic was als be cnfined t crn planter tractr wheel tracks. The S and N treatments were n tilled. The plts were seeded t Pineer 3788 crn at 6 16, seeds/acre n May 14, 1 with a 6-rw planter. Lrsban 15G G 1 lbs./acre (1.5 lbs./acre a.i.) was applied at seeding. N starter fertilizer was used. Lass + Bladex ( lbs./acre /a.i.) was bradcast pre-emergence n May 15 and 16. Crp residue measurements after planting were taken n May 16. Anhydrus ammnia was applied at 12 lbs. N/acre n May 31. Tw 1-ft rws in each plt were staked ut n June 4, 1 and heights f crn plants were measured n June 2, July 7, July 19, and August 3 t recrd any plant grwth differences. Plts were cultivated n June 25. Atrazine + Crp Oil (1.5 lbs./acre a.i. + 1 gal./acre) was bradcast pst-emergence n July 24. Tasseling and silking ntes were recrded frm July 29 thrugh Aug 3. Plts were harvested fr grain with a JD 33 cmbine n Octber 5, 1. A grain sample was retained. Bulk crn was harvested frm the plts n Octber 8 and crn stalks were chpped n all treatments. The MSS and M treatments were plwed using an nland hitch with 6 18-inch bttms n Octber 24 and the CSS and C treatments were chiseled with a 15-ft pull type chisel plw n Octber 23. Pst-tillage crp residue measurements were taken n Nvember 6, 1. SOIL SAMPLING PROCEDURES: Tw 2-ft sil cres were taken frm each plt in wheel track and nn-wheel track areas after crn planting n May 18 and 21. N attempt was made t keep track f the subsiler slts, s sme sampling may have cincided with the slts and sme sampling wuld have ccurred in areas between subsiler slts. Plts were sampled t a depth f 2 feet in -6, 6-12, 12-18, inch increments. The sil samples were weighed, dried at 15 C, and weighed back fr bulk density and sil misture determinatin. Penetrmeter readings were taken n May 21. After grain harvest in the fall f 1, but befre any fall tillage, tw 2-ft sil cres in -6, 6-12, 12-18, and inch increments were again taken in wheel track and nn-wheel track areas f each plt fr bulk density and sil misture determinatin. At the same time ne 2- t 5-ft sil cre in 24-36, 36-46, and 48-6 inch increments was taken in the wheel track and nn-wheel track areas f each plt fr sil misture determinatin. Sampling tk place n Octber 9 and 1, and penetrmeter readings were taken n Octber 1, 1. MEASUREMENTS AND DISCUSSION: Grwing cnditins were smewhat pr in 1 with adequate misture available thrugh June but then very dry cnditins in July, August, and September. Summaries f residue and plant measurements are given in Table 1. Subsiling did nt affect residue cver in pre-plant r r\ pst-plant measurements. There was a significant subsiling by tillage interactin n residue measurements made prir t crn planting, but there was n interactin n pst-plant residue measurements (Tables 1 and 2). Tillage systems did significantly affect residue cver. Date f tasseling, date f silking, grain misture at harvest, and bushel weight were significantly influenced by tillage. The mldbard treatment tasseled earlier, silked earlier (except fr the chisel treatment), had lwer grain misture, and a heavier test weight than the ther treatments. Grain yield was nt influenced by tillage, subsiling, r their interactin. The height f crn plants measured at 2-week intervals beginning 37 days after planting is given in Table 3. Crn plant height was significantly influenced by tillage at all measuring dates and als significantly influenced by subsiling n August 3. There were n subsiling by tillage interactins. The mldbard plw treatment had significantly taller plants than the spring disk and n-till treatments at all dates and taller plants than the chisel treatment at all dates, significantly s n July 6 and July 19. An verall statistical analysis f the vlumetric sil misture taken in the study is given in Table 4. In the spring f 1 a significant tillage by depth interactin shws that sil misture cntent was greater in the spring disk and n-till treatments than in the mldbard plw and chisel plw treatments at the -6 inch depth and pssibly at the 6-12 inch depth (Table 5). The wheel traffic by depth interactin was significant in bth the spring and fall f 1 shwing a difference in the upper 12 inches but n r very little difference ccurring belw the 12-inch depth (Table 6). In bth the spring and fall, the wheel track areas had greater sil misture cntent in the upper 12 inches than the nn-wheel track areas. There was n increase in sil misture cntent belw 12 inches in the wheel track areas in the spring and nly a slight Increase In the and inch depths in the fall. Subsiling did nt significantly affect any sil misture measurement. An verall statistical analysis f bulk densities taken in the study is given in Table 7. There was a significant tillage by depth interactin n bulk densities in the fall f 1 (Table 8). The mldbard plw treatment had a lwer bulk density than spring disk and n-till treatments at all sil depths. Th*w chisel plw treatment had the same bulk density as mldbard plw and a lwer bulk density than spring i disk and n-till at 6-12, 12-18, and inch sil depths. At the -6 inch depth, chisel plw had the same bulk density as spring disk and n-till and a higher bulk density than mldbard plw. The tillage