Ricardo Melgar INTA Exp. ST. Pergamino Argentina...Ricardo Melgar. INTA Exp. ST. Pergamino....
Transcript of Ricardo Melgar INTA Exp. ST. Pergamino Argentina...Ricardo Melgar. INTA Exp. ST. Pergamino....
Ricardo MelgarINTA Exp. ST. PergaminoArgentina
FLUID FERTILIZER FORUM Scottsdale, Feb 15-16, 2010
N soil - NO3-
N atmosphere N – NBF
Soybean - Bradyrhizobium
2N2 + 3H2Nitrogenase 2NH3
NH3 + R-COOH Proteins
Soybean - N uptake
0
100
200
300
400
0 20 40 60 80 100 120
Días después de la siembra
Re
qu
eri
mie
nto
de
N (
kg
/ha
)
Nodulada (5431 kg/ha)
Sin nodular (4400 kg/ha)
R3 - R6 maximum N assimilation. High supply by BNF
Critical stage of seting
nodules from the inoculant
Up to R1 minimum N requirements, soil supply
228194
35 3411
-183
10
-250
-200
-150
-100
-50
0
50
100
150
200
250
N Total NBF Soil Residue
- Top
Residue
-Roots
Exported N
Balance
N B
ala
nce in s
oybean c
rop
kg.h
a-1
Controversial Facts
Compete with BNF
Inhibits nodule formation & infestation
Inefficient – very low NUE
Grain yield is directly related to N total in plant
NBF Provides near 52 % of total N uptake
The proportion of fixed N decreased with increasing fertilizer-N additions
Controlled release fertilizers
Delays transformation of N of urea-compounds into soluble forms (NH4
+) Nitamin & Nitamin NFusion
(Georgia-Pacific)
Inhibitors of urease
Delays transformation of urea into NH4
+
Agrotain
Synchronization of N in soil with plant needs maximum uptake
∆ Yield with 30 kg N ha-1: 197 kgha-1
Six site-year experiments 2000-03 South Santa Fe-North Buenos Aires
2.00
3.00
4.00
5.00
Check N 200 -
Sowing
Inoculated Inoc.&Co+Mo N 30 - R3 N 30 - V4
Soybean g
rain
yie
ld M
g /
ha DLS 5%: 269 kg/ha
N fertilization in soybean in Pergamino
Previous works
To evaluate the effect of increasing late N availability by improving placement/product combinations of fluid N sources on soybean grain yields and N uptake
Four sites in 2008-091. Mercedes (Corrientes)
2. Crespo(Entre Rios)
3. Ocampo (N Buenos Aires)
4. Acevedo (N Buenos Aires)
Repeated in 2009-10
Product Placement
No N Fertilizer --
Ammonium Nitrate
Broadcast
Nitamin®
Knifed or Dribbled
Nitamin NFusion
Urea solution
Idem + 0.5% Agrotain
Nine 40 kg N ha-1treatments& Check (No N)
Total aboveground biomass at R5. Splitting leaves, stems and pods
N concentrations in leaves stems & pods
N uptake in aboveground biomass at R5
Grain yields
Total aboveground biomass at harvest
Grain protein
The country’s worst drought in 50 years has cut agriculture output almost 20%.
Disastrous consequences for the farmers, for the rural towns, the agribusiness chain and the whole country’s economy
Satellite imagery of vegetation of December 2008 relative to same month of 1996-2007 series
Site CheckMean All N
∆Yield
Kg ha -1
Mercedes 1825 2252 427
Crespo 1953 2270 317
Ocampo 1963 2069 106
Acevedo 1471 1219 -252
0
200
400
600
800
1000
1200
244
254
264
274
284
294
304
314
324
334
344
354
364 8
18
28
38
48
58
68
78
88
Acc
um
ula
ted
mm
Julian day
Pergamino
Precip ETP
0
200
400
600
800
1000
244
254
264
274
284
294
304
314
324
334
344
354
364 9
19
29
39
49
59
69
79
89
Acc
um
ula
ted
mm
Julian day
Crespo
Precip ETP
We were unable to find site factors that explain N response differences
1,000
1,200
1,400
1,600
1,800
2,000
2,200
2,400
2,600
2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000
Gra
in y
ield
kg/ha
Total aboveground biomass kg/ha
Grain vs. TDM yields
r= 0.74 **
1750
1800
1850
1900
1950
2000
2050
115 120 125 130 135
Soybean g
rain
yie
ld k
g/ha
Grain N uptake kg/ha
Treatment means overall
sites
Treatments Protein
Check 37.0 %
Control 37.8 %
All N Knifed 37.3 %
All N Dribbled 37.0 %
0
500
1,000
1,500
2,000
2,500
3,000
40 60 80 100 120 140
Gra
in Y
ield
kg/ha
N uptake in biomass at R5 (kg/ha)
Grain vs. N uptake at R5
3000
3500
4000
4500
1,500
1,625
1,750
1,875
2,000
2,125
2,250
Tota
l D
ry M
att
er
yie
ld k
g/ha
Soyb
ean g
rain
yie
ld k
g/ha
Grain TDM
LSD 5% Grain: 497 kg/ha - TDM: 919 kg/ha
Grains yield correlated to N uptake
We could not find site factors associated to N response differences
There were not differences among treatments
Final Considerations
The severe lack of rains during the critical periods of filling grains prevented the attain of a high yield that could stress the N symbiotic capacity to supply N to crops.
N was of ample abundance for the limited grain and biomass yields obtained.
We expect that a next season, with a different weather pattern, especially under a higher precipitation scenario, the treatment differences would allow reaching a more conclusive effect
We Acknowledge The Fluid Fertilizer Foundation for their support in this research
We thanks very much to our collaborators. Gabriel, Enrique and Francisco