Pre-Plant Broadcast Urea in Direct Seeding, A Logistical Return to the Past? Tom Jensen

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1 Pre-Plnt Brodcst Ure in Direct Seeding, A Logisticl Return to the Pst? Tom Jensen Interntionl Plnt Nutrition Institute (IPNI), Northern Gret Plins Director Downey Rd., Ssktoon, SK S7N 4L8 Ph: Fx: E-mil: tjensen@ipni.net ABSTRACT A study ws conducted to compre the crop yield response between fll nd spring surfce brodcst pplictions of ure to the industry stndrd of side-bnding ure during the spring plnting opertion. The results of four-yer study of brley direct seeded (no-till) t Ellerslie, AB, hving tretments of fll nd spring pplictions of surfce pplied ure, with nd without urese nd nitrifiction inhibitors, compred to side-bnded ure t plnting in the spring, showed tht the brodcst pplictions performed well in comprison. There re numerous frm opertions tht re switching from side-bnding to pre-plnt brodcst ure pplictions to reduce the time of plnting in the spring. BACKGROUND There re three min sources of nitrogen (N) fertilizer commercilly vilble in the western Cnd mrket. These re pressurized liquid nhydrous mmoni (82-0-0), grnulr ure ), nd liquid ure mmonium nitrte (28 or ). Previous to the yer 2005 there ws lso ccess to grnulr mmonium nitrte (34-0-0). But due to dded security costs nd risks is not redily vilble. There re three min potentil loss mechnisms of N, fter N fertilizer is pplied to soils. One is leching of nitrte with wter moving through the soil profile, nother is denitrifiction of nitrte under sturted soil conditions primrily in the spring t time of snowmelt, nd mmoni voltiliztion losses from surfce pplictions of ure fertilizer, when there is sufficient moisture to dissolve the ure, but not move it into the soil. When no-till or direct seeding ws first introduced to western Cnd cropping systems, the common wy to pply N fertilizer ws brodcst opertions. Under conventionl tillge the N fertilizer ws normlly pre-plnt brodcst ppliction followed by n incorporting tillge opertion before plnting. Erly reserch evluting surfce pplictions of N fertilizer to no-till fields showed tht mmonium nitrte hd higher use efficiency compred to ure. An erly study ner Foremost, AB, showed no difference in the content of N-15 enriched ure or mmonium nitrte, in whet grin under conventionl tillge when the N fertilizer ws brodcst nd incorported with tillge prior to plnting. However, under no-till cropping the surfce pplied mmonium nitrte hd higher fertilizer uptke into the whet grin compred to ure (Tble 1). It ws thought tht the lower grin content of fertilizer N ws due to mmoni voltiliztion losses when surfce pplying ure without incorportion with tillge opertion (Jensen 1985).

2 Tble 1. Pre-plnt brodcst fertilizer N uptke into spring whet grin, Foremost, AB, 1980 Tillge System N Fertilizer Form Rte kg N/h % of Applied Fertilizer in Grin Sttisticl Significnce, 0.05% * No-till, no incorportion Ure b b Ammonium Nitrte Conventionl Ure Tillge, with incorportion Ammonium Nitrte *Seprte nlysis within tillge system, L.S.D. No-till 10, Conventionl Tillge 14. Further relted reserch showed tht when bnded ure ws compred to brodcst ure under no-till cropping, in two out of three site-yers bnding resulted in higher yields of spring whet (Tble 2). Tble 2. Spring whet yields kg grin/h, compring brodcst ure to bnded ure under no-till cropping Plcement of Rte kg N/h Site Yer Ure Fertilizer Crmngy, AB, 1981 Crmngy, AB, 1982 Glenwood, AB, 1982 Brodcst , b* 1433, b 1786, Bnded , 1992, 2040, * Sttisticl differences within ech individul site yer. This nd much other erly 1980s reserch encourged the development of plnting equipment tht ws cpble of side-bnding N fertilizer t the time of plnting. This N fertilizer plcement method is now the most commonly used wy to pply N fertilizer. However, s frm size hs become lrger the logisticl demnds to plnt lrge cres of crops within the short time frme of erly to mid-my idelly, hs encourged frmers to consider returning to brodcsting ure s pre-plnt ppliction, rther thn side-bnding ure during the plnting opertion. This is becuse the time sved by not stopping s long to fill plnting equipment tnks with seed, strter fertilizer (mostly P fertilizer), nd dditionlly hndling the ure fertilizer, llows more cres to be plnted in dy. On lrge corporte frm, pproximtely 40,000 cres, in southern Ssktchewn it is estimted tht shifting ure ppliction to pre-plnt brodcst ppliction llows plnting to be completed two weeks erlier compred to side-bnding t plnting (source: personl communiction with frm mngement). It is dditionlly estimted tht crop yields re 15 to 20% greter due to erlier plnting, compred to fields tht would hve been plnted lter in My insted. MATERIALS AND METHODS

3 A four-yer study ws conducted t the University of Albert reserch frm south of Edmonton, by pplying vrious forms of ure fertilizer pplied s lte fll or erly spring brodcst opertion under direct seeding, compred to the industry stndrd of side-bnding untreted ure t plnting. Brley ws direct seeded on whet or cnol stubble for the yers 2010 through The tretments in the study included both regulr (4mm) nd lrge grnule ure (13mm), tht ws treted with, or not treted with n urese inhibitor (Agrotin), or the urese inhibitor plus one of two nitrifiction inhibitors (Nitrpyrin or DCD). The fll brodcst pplictions were done usully ner mid-october, the spring pplictions were dome in mid-april, with plnting done lst week of April or first week of My ech yer depending on when field trvel ws possible. All N fertilizer rtes were suboptiml (40 kg N/h) to try to see if there were differences between the forms of the vrious treted ure products, nd the side-bnded ure t plnting. RESULTS AND DISCUSSION It ws expected tht the industry stndrd of side-bnding ure t plnting would be the highest yielding tretment ech yer of the study. However, both the fll nd spring brodcst pplictions with or without ddition of urese inhibitor, or urese inhibitor plus nitrifiction inhibitor yielded similrly compred to side-bnding t plnting (Tble 3). Also, there ws no observed difference between the size of ure grnules. There ws significnt observed response to dded N fertilizer in ll yers except 2011, s observed by the check or zero-n tretment yielding lower thn ll N fertilizer tretments for those three yers. Tble 3. Yield of brley (kg /h), by N fertilizer plcement tretment, t the U of A Reserch Frm south of Edmonton, AB, in yers 2010 through 2013 Form-Timing - Plcement Ure Side-bnded b 5373 b Ure Spring Brodcst b Ure Fll Brodcst b Super Ure Fll Brodcst b 5566 b

4 Agrotin treted Ure Fll b 6047 Lrge Super Ure Fll b 5703 b Lrge Super Ure Spring b 5353 b Check no N 3093 b b 4625 b CONCLUSIONS AND RECOMMENDATIONS It ppers tht for the four yers of this study, brodcst pplictions of ure t lower rtes of N ppliction give brley yields s high s side-bnding ure t plnting. This ws unexpected, but mybe shows tht perhps there is not s gret or consistent of dvntge of bnd plcement t plnting compred to pre-plnt brodcst pplictions s previously thought. Admittedly, it is quite possible tht for the four site-yers of this study rinfll ws timely fter brodcst pplictions nd voltile losses of mmoni from brodcst ure pplictions under direct seeding were miniml or not experienced. It is dvised tht this reserch be continued with rnge of N fertilizer rtes, s well s more yers nd include more reserch sites. REFERENCE Jensen T L Methods of ppliction of nitrogen fertilizer for no-till cropping. MSc Thesis, Deprtment of Soil Science, University of Albert, Edmonton, AB.

5 Pre-Plnt Brodcst Ure in Direct Seeding, A Logisticl Return to the Pst? Tom Jensen Interntionl Plnt Nutrition Institute

6 Why Did We Go from Brodcst N to Bnded N t Plnting? Agronomics higher yields Environmentl less loss into the environment Economics better net profits for frmers 2

7 Commonly Commercilly Avilble N Fertilizers Nme Chemicl Formul Anlysis % N-P 2 O 5 -K 2 O Anhydrous Ammoni NH Ammonium Nitrte** NH 4 NO Ure* CO(NH 2 ) Ure Ammonium Nitrte (UAN) solution NH 4 NO 3 + CO(NH 2 ) 2 + H / * Commonly vilble ** Very limited bsiclly no vilbility

8 Nitrogen Leching Mobile NO - 3 removed from the root zone, perhps NH + 4 on sndy soil by downwrd wter movement Concern bout contmintion of groundwter Plnt- Avilble N NO 3 - Leching

9 Atmosphere (N 2 ) Denitrifiction NO 3 - bcteri without oxygen N 2 or N 2 O Wet soils (poor ertion) Increses with incresing temp Increses with crop residue mount N lost to the tmosphere s gs Plnt- Avilble NO 3 -

10 Voltiliztion Atmosphere Loss of NH 3 gs to the tmosphere - NH 4 + forms converted to NH 3 Surfce pplictions of mmonium, high ph; or ure, urese enzyme on surfce High tempertures Improper moisture conditions Improper ppliction of mmoni Plnt- Avilble N NH 4 +

11 Ure Ammonium Nitrte b b NH 3 Voltiliztion Ure Ammonium Nitrte

12 Brodcst compred to bnded b b

13 Timing nd Plcement of Ammonium Nitrte in No-till Whet b b c d b c b c b d e e

14 Bnding Benefit for No-Till Cropping

15 Right Right Time Right Rte Right Plcement,(Bnded?) Cndin Fertilizer Institute

16 Should we question whether or not Bnding ure is superior enough compred to Brodcst ure? My exposure to Montn nd North Dkot % frms side-bnding <5%, 95% pre-plnt brodcst for spring seeded crops Lrge corporte frms in SK choosing to brodcst ure, usully pre-plnt Less time to plnt during limited plnting seson 40,000 cres, plnting done 2 weeks sooner, 15% yield dvntge, erlier hrvest Less lbor Using urese inhibitor, lower potentil voltile NH3 losses by hlf Cheper to own couple of floters nd single shoot irdrills, compred to side-bnd irdrills nd extr trucks plus lbor to hul fertilizer during the plnting opertion. Recent reserch on urese nd denitrifiction inhibitor treted ure

17 Ellerslie, AB, Yield Brley, kg h-1 LSD 0.05 Form-Timing - Plcement Ure Sidebnded Ure Spring Brodcst Ure Fll Brodcst Super Ure Fll Brodcst Agrotin treted Ure Fll Lrge Super Ure Fll Lrge Super Ure Spring b 5373 b b b b 5566 b b b 5703 b b 5353 b Check no N 3093 b b 4625 b

18 Compre 90 kg N h -1 Tretments Form Rte Plcement Yield kg h -1 Agrotin 90 Brodcst Spring 6229 Ammonium 90 Brodcst Spring 6145 Nitrte Ure 90 Brodcst Spring 6092 b ESN 90 Seed-Row Plnting 5917 b c Super Ure 90 Brodcst Spring 5768 b c Super Ure 90 Bnd t Plnting 5738 c Sttisticl Significnce ESN 90 Bnd t Plnting 5280 d Ure 90 Bnd t Plnting 4659 e ESN 90 Brodcst Spring 4520 e Agrotin 90 Bnd t Plnting 4515 e Ammonium 90 Bnd t Plnting 3447 f Nitrte Check 0 NA 2818 g 336 LSD t 0.05

19 Is bnded ure s much better thn brodcst ure s I thought? Mybe Mybe not Needs more reserch? Questions