efisiensi pupuk dan pemupukan nitrogen
DESCRIPTION
EFISIENSI PUPUK DAN PEMUPUKAN NITROGEN. Bahan kajian MK Pemupukan Dosen : Prof Dr Ir Soemarno MS Jur Tanah FP UB, 2011. NITROGEN EFFICIENCY AND FALL N APPLICATIONS. Larry G. Bundy Department of Soil Science University of Wisconsin. NITROGEN FERTILIZER EFFICIENCY. - PowerPoint PPT PresentationTRANSCRIPT
EFISIENSI PUPUK DAN
PEMUPUKAN NITROGEN
Bahan kajian MK PemupukanBahan kajian MK Pemupukan
Dosen: Prof Dr Ir Soemarno MSDosen: Prof Dr Ir Soemarno MS
Jur Tanah FP UB, 2011Jur Tanah FP UB, 2011
NITROGEN EFFICIENCY AND
FALL N APPLICATIONS
Larry G. BundyLarry G. Bundy
Department of Soil ScienceDepartment of Soil Science
University of WisconsinUniversity of Wisconsin
NITROGEN FERTILIZER EFFICIENCY
Crop uptake of fertilizer NCrop uptake of fertilizer N
Amount of N fertilizer Amount of N fertilizer appliedapplied
% NFE = x 100
Improved N Management
Higher Crop Recovery of Available N
Reduced Risk of N Loss
Nitrogen Management Decisions
Rate Rate SourceSourceTimingTimingNitrification inhibitorsNitrification inhibitors
Nitrogen Loss Processes
Leaching Leaching DenitrificationDenitrification Ammonia volatilizationAmmonia volatilization
Nitrogen ReactionsNitrogen Reactions
Mineralization (Ammonification):
Soil Organic NH4-NN
+
Ammonium
Soil Organic Matter Most Midwest soils = 1-5% Most Midwest soils = 1-5% Organic soils = 20-50+ % Organic soils = 20-50+ % Nitrogen Content (O.M.) = 5% NNitrogen Content (O.M.) = 5% N About 2-3% of O.M. decomposes About 2-3% of O.M. decomposes
annuallyannually
Nitrogen ReactionsNitrogen Reactions
Nitrification:
NH4+ NO2
- + H+
NO2- NO3
- NitrateNitrite
(Nitrosomonas)Ammonium
(Nitrobacter)
Nitrite
Nitrogen ReactionsImmobilization:
NO3- or NH4
+ Organic N
InorganicNitrogen
organisms
Carbon : Nitrogen ratio Carbon : Nitrogen ratio effects on N releaseeffects on N release
Expected N EffectExpected N Effect C : N rangeC : N range
Release NRelease N < 20< 20
Depends on Depends on CompositionComposition
20 – 5020 – 50
Immobilize (Tie up) NImmobilize (Tie up) N > 50> 50
Carbon: Nitrogen Ratios Carbon: Nitrogen Ratios of Organic Materialsof Organic Materials
MaterialMaterial C : N RatioC : N Ratio
Soil microorganismsSoil microorganisms 88
Soil organic matterSoil organic matter 1010
AlfalfaAlfalfa 1212
Rotted manureRotted manure 2020
Corn residueCorn residue 6060
Grain strawGrain straw 8080
SawdustSawdust 300300
Nitrogen ReactionsDenitrification:
NO3- N2 + N2O
Gases lost to Atmosphere
organisms
Wet SoilsLow OxygenNitrate
Nitrogen Timing Options
FallFallPreplantPreplantSidedressSidedressPost-emergencePost-emergenceSplitSplit
Timing of Nitrogen Uptake by Corn
0
30
60
90
120
150
180
210
240
Time during growing season
N u
ptak
e, lb
N/a
cre
Apr. May June July Aug. Sept. Oct.
FALL N APPLICATIONS AND RESIDUE DECOMPOSITION
Objectives
Determine the influence of pre-season (fall) Determine the influence of pre-season (fall) N fertilization at low rates (30 and 100 lb N fertilization at low rates (30 and 100 lb N/acre) on corn residue decomposition in N/acre) on corn residue decomposition in no-till corn production.no-till corn production.
Monitor the effects of pre-season (fall) N Monitor the effects of pre-season (fall) N treatments and residue chopping on residue treatments and residue chopping on residue quantity, carbon and nitrogen composition, quantity, carbon and nitrogen composition, and soil temperature.and soil temperature.
Treatments
Times and rates of N (UAN and Times and rates of N (UAN and ammonium sulfate)ammonium sulfate)
Sulfur as gypsum applied to Sulfur as gypsum applied to equalize sulfur equalize sulfur
Residue fall chopped or not Residue fall chopped or not chopped. chopped.
Measurements
Soil nitrate (Fall, PPNT, PSNT)Soil nitrate (Fall, PPNT, PSNT)Residue quantity and Residue quantity and
compositioncompositionSoil temperature, 4 in. depthSoil temperature, 4 in. depthCorn silage and grain yieldCorn silage and grain yield
TreatmentsN timing, source, & rate (lb N/a)
FallFall SpringSpring TotalTotal
00 00 00
30 UAN30 UAN 00 3030
30 AS30 AS 00 3030
100 AS100 AS 00 100100
00 100 AS100 AS 100100
30 UAN30 UAN 160 UAN160 UAN 190190
30 AS30 AS 160 AS160 AS 190190
00 190 UAN190 UAN 190190
00 190 AS190 AS 190190
100 AS100 AS 90 UAN90 UAN 190190
Nylon mesh bag for residue quantity & composition measurements
Dry matter amounts at several times in the chopped residue treatment,
Arlington, WI 1998-2001 SamplingSampling
timetime
---- Residue (lb dry matter/acre) -------- Residue (lb dry matter/acre) ----
1998-991998-99 1999-20001999-2000 2000-20012000-2001
NovemberNovember 70307030 56675667 60236023
AprilApril 61216121 51025102 49584958
JuneJune 54175417 47244724 47994799
SeptemberSeptember ------ 18901890 36213621
Effect of N treatment on corn residue decomposition, Arlington, 1999-2000.
DateDate
Fall NFall N 30 Apr 0030 Apr 00 27 Jun 0027 Jun 00 26 Sep 0026 Sep 00
-lb N/acre--lb N/acre- -- % residue remaining ---- % residue remaining --
00 92 a92 a 8787 3131
30 UAN30 UAN 94 a94 a 9090 2929
30 AS30 AS 97 a97 a 7979 3535
100 AS100 AS 76 b76 b 7878 3535
Carbon/nitrogen ratio and N content of
corn residue at various dates, Arlington, WI, 1999-2000.
N contentN content
DateDate C/N ratioC/N ratio -- lb N/acre ---- lb N/acre --
10 Nov 9910 Nov 99 7474 3333
30 Apr 0030 Apr 00 4747 4848
27 Jun 0027 Jun 00 3737 4545
26 Sep 0026 Sep 00 2828 2222
Nitrogen timing, source, & rate effects on corn grain yield, Arlington, 1999-2001
N timing & rateN timing & rate
(lb N/acre)(lb N/acre)
Yield Yield 19991999
Yield Yield 20002000
Yield Yield 20012001
FallFall SpringSpring -------------- bu/acre --------------------------- bu/acre -------------
00 00 167 b167 b 63 e63 e 105 e105 e
30 UAN30 UAN 00 180 b180 b 60 e60 e 126 d126 d
30 AS30 AS 00 178 b178 b 66 e66 e 126 d126 d
100 AS100 AS 00 209 a209 a 112 d112 d 175 c175 c
00 100 AS100 AS 216 a216 a 128 cd128 cd 171 c171 c
Nitrogen timing, source, & rate effects on corn grain yield, Arlington, 1999-2001
N timing & rate N timing & rate
(lb N/acre)(lb N/acre)
Yield Yield 19991999
Yield Yield 20002000
Yield Yield 20012001
FallFall SpringSpring ---------------- bu/acre --------------------------- bu/acre -----------
00 00 167 b167 b 63 e63 e 105 e105 e
30 UAN30 UAN 160 UAN160 UAN 219 a219 a 146 abc146 abc 191 b191 b
30 AS30 AS 160 AS160 AS 220 a220 a 158 a158 a 202 ab202 ab
00 190 UAN190 UAN 219 a219 a 148 ab148 ab 194 b194 b
00 190 AS190 AS 216 a216 a 160 a160 a 208 a208 a
100 AS100 AS 90 UAN90 UAN 220 a220 a 136 bc136 bc 207 a207 a
Summary
About 60 to 70% of corn residue About 60 to 70% of corn residue decomposed during the subsequent decomposed during the subsequent growing season.growing season.
C/N ratio of residue usually decreased C/N ratio of residue usually decreased from the initial November value from the initial November value through the following September. through the following September.
Most of this change was due to carbon Most of this change was due to carbon loss.loss.
Summary For production, fall N additions to promote For production, fall N additions to promote
residue decomposition do not appear to be residue decomposition do not appear to be justified. justified.
Improvements in yield or other agronomic Improvements in yield or other agronomic benefits were not observed in this study.benefits were not observed in this study.
Fall N can increase potential for over winter N Fall N can increase potential for over winter N loss.loss.
Ammonium sulfate provided more consistent Ammonium sulfate provided more consistent crop responses than UAN solution.crop responses than UAN solution.
Improving Fall N Effectiveness
Use ammonium forms of N. Use ammonium forms of N. Use a nitrification inhibitor Use a nitrification inhibitor
(N-Serve) with fall N. (N-Serve) with fall N. Delay N application until soil Delay N application until soil
temperature remains below temperature remains below 5050o o F.F.
INHIBITION OF NITRIFICATION
NH4+ NO2 NO3
Inhibitor action
Ammonium(Held by soil)
Nitrite Nitrate(Subject to loss)
Improving Fall N Effectiveness
Use ammonium forms of N. Use ammonium forms of N. Use a nitrification inhibitor Use a nitrification inhibitor
(N-Serve) with fall N. (N-Serve) with fall N. Delay N application until soil Delay N application until soil
temperature remains below temperature remains below 5050o o F.F.
Time of anhydrous ammonia application and N-Serve effect on corn grain yield. Waseca, MN
TimingTiming
YearYear FallFall Fall +Fall +N-SN-S SpringSpring Signif.Signif.
------------- bu/acre ------------------------- bu/acre ------------
19971997 186186 189189 180180 NSNS
19981998 199199 207207 195195 NSNS
19991999 109109 154154 187187 ****
20002000 135135 139139 160160 ****
14-yr ave 14-yr ave 11// 144144 153153 15515511/ 1987-2000 ave., 135 lb N/a, Soybean-Corn rotation (Randall, / 1987-2000 ave., 135 lb N/a, Soybean-Corn rotation (Randall, 2000)2000)
Soil nitrate to ammonium ratios as affected by date of anhydrous ammonia application and N-Serve
Application dateApplication date11//
Sampling Sampling datedate
Oct. 28Oct. 28w/o N-Sw/o N-S
Oct. 28Oct. 28w/ N-Sw/ N-S
Nov. 19Nov. 19w/o N-Sw/o N-S
-------- Nitrate:Ammonium ratio ---------------- Nitrate:Ammonium ratio --------
Apr. 20Apr. 20 0.80.8 0.40.4 0.10.1
May 15May 15 2.52.5 1.21.2 0.20.2
May 30May 30 3.63.6 1.91.9 0.50.5
11/ Soil temp. (6 in. depth) = 47/ Soil temp. (6 in. depth) = 47oo on 10/28 and 34 on 10/28 and 34oo on 11/19 on 11/19 (Randall, MN, 1997).(Randall, MN, 1997).
Effect of N Rate and Time of Application on Nitrate-N Losses and Corn Yield
NitrogenNitrogen Annual Loss ofAnnual Loss of 5-Yr Yield 5-Yr Yield
RateRate TimeTime NONO33-N in Drainage-N in Drainage AverageAverage
lb/Alb/A - lb/A/yr -- lb/A/yr - bu/Abu/A
00 - -- - 77 6666
120120 FallFall 2727 131131
120120 SpringSpring 1919 150150
180180 FallFall 3434 160160
180180 SpringSpring 2626 168168
* Ammonium sulfate applied about 1 Nov. or 1 May. * Ammonium sulfate applied about 1 Nov. or 1 May. MinnesotaMinnesota
Nitrogen timing and nitrification inhibitor effects on corn yield, Fond du Lac Co., WI, 1994
M. Rankin, UW-Extension140 lb N/a as anhydrous ammonia
N timingN timing N-ServeN-Serve YieldYield
bu/acrebu/acre
NoneNone ---- 7070
FallFall nono 132132
FallFall yesyes 143143
SidedressSidedress nono 169169
SidedressSidedress yesyes 166166
Fall N Applications
Fall N has higher risk of loss. Fall N has higher risk of loss. Performance of fall N is better where Performance of fall N is better where
over winter soil temperatures retard over winter soil temperatures retard conversion of ammonium to nitrateconversion of ammonium to nitrate..
Best results with medium-textured Best results with medium-textured soils with relatively good drainage.soils with relatively good drainage.
Fall N Applications
Soil temperature history (calendar Soil temperature history (calendar date) may be more useful than date) may be more useful than daily measurements.daily measurements.
Low rates of ammonium sulfate in Low rates of ammonium sulfate in fall can provide S in combination fall can provide S in combination with P&K fertilizers application.with P&K fertilizers application.