Fertilizers to sustain the production of 100 million tonnes
of grain in Argentina 1
Fernando O. García
INPOFOS Cono Sur
Potash and Phosphate Institute - Potash and Phosphate Institute of Canada
Av. Santa Fe 910 – (B1641ABO) Acassuso, Buenos Aires, Argentina
[email protected]
Grain production in Argentina, especially soybean, has sharply increased
in the last decade (Fig. 1). A report of “Fundación Producir Conservando” has
projected a potential production of 100 million t of grain for 2010/11 (Table 1)
(Oliverio and López, 2002). This potential increase in production is expected
from increases in planted area as well as in average yields of the main grain
crops.
Sustainability is an ineludible objective for the agricultural ecosystems of
the XXI century. Adequate crop rotations; soil organic matter balances; control
of soil erosion; crop management practices; soil management; weeds, insects
and diseases control; and nutrient supply are required to reach a production
goal of 100 million t of grain.
Adequate crop nutrient supply is only possible in soils of high fertility.
Most of the grain production regions of Argentina, the Pampas and the extraPampas areas, have been developed under soils of high native fertility.
However, negative soil nutrient balances along the 100-years of cropping
history have resulted in the deterioration of the fertility levels in most of the
regions (Andriulo et al., 1996 ; García, 2001). A sustainable agricultural
production to reach the goal of 100 million t of grain requires to improve soil
nutrient balances.
Crop fertilization is the main tool to get high yields and improve current
nutrient balances in grain crop production. Nutrients generally deficient in the
Pampas and other grain production regions, are nitrogen (N), phosphorus (P)
and, in the last years, sulfur (S). Deficiencies and responses to other nutrients
such as potassium (K), magnesium (Mg), and micronutrients have been
reported for specific crops and areas.
A report recently released by “Fundación Producir Conservando” (Olivero
et al., 2004), has estimated the potential fertilizer consumption by grain crops
for the goal of 100 million t in 2010/11 considering an improvement of soil
nutrient balances. This paper discusses the results of this projection and of
recent field experimentation on grain crop fertilization.
Projection of fertilizer consumption for 2010/11
Fertilizer consumption in Argentina has steadily increased since the early
90’s at a rate of 146000 t per year (Fig. 2). However, despite of this increase,
Presented at the 6ª Conference “Fertilizantes Cono Sur” organized by British Sulphur Pub. –
Punta del Este, Uruguay – 21-23 November 2004.
1
2
Grain production (thousand t)
nutrient balance (nutrient application vs. nutrient removal) is still negative (Fig.
3). In the last years, the removal:application ratio for N, P, K, and S in the main
grain crops has been of 3-5, 2-2.5, 50-100, and 10-100, respectively.
Corn
Wheat
40000
35000
Soybean
Sunflower
30000
25000
20000
15000
10000
5000
0
1990
1992
1994
1996
1998
2000
2002
2004
Fig.1. Evolution of corn, wheat, soybeans, and sunflower production in
Argentina. Period 1991-2003. Source: SAGPyA.
Table 1. Total production, harvested area, and average yield of the main grain
crops of Argentina in 2001/02 and projected for 2010/11 (Oliverio and López,
2002).
Corn
Production
(thousand t)
Area
(thousand ha)
Average Yield
(kg/ha)
14710
Sorghum Soybean
Sunflower
Estimated in 2001/02
2854
30000
3800
Wheat
Others
Total
15300
2938
69602
1559
24822
2436
541
11420
2027
6840
6039
5275
2627
1875
2237
Projected for 2010/11
2564
44757
7849
17476
2939
99280
3653
6113
1732
31147
2149
2859
Production
23695
(thousand t)
Area
2996
404
16249
(thousand ha)
Average Yield
7909
6346
2724
(kg/ha)
# Others include rice, oats, millet, rye, peanuts, barley.
2804
3250
3
Estimated fertilizer consumption
(thousand ton)
2500
2000
1500
1000
Consumption = 146 Year - 289964
R 2 = 0.893
500
0
1990
1992
1994
1996
1998
2000
2002
2004
Year
Fig. 2. Evolution of fertilizer consumption in Argentina. Period 1991-2003.
Adapted from data of SAGPyA and Fundación Producir Conservando.
NPKS Removal
Sunflower
Soybean
Wheat
Corn
1504
1200
900
743
600
320
300
195
0
1500
thousand ton
thousand ton
1500
NPKS Application
1200
900
600
445
300
128
0
N
P
K
S
N
P
17
28
K
S
Fig. 3. Nutrient removal and application in the four main grain crops of
Argentina in the 2003/04 season. Removal of N in soybean was reduced
by 50% considering supply by biological N fixation. Adapted from data of
SAGPyA and Fundación Producir Conservando.
4
The report of “Fundación Producir Conservando” considered only N, P,
and S to estimate fertilizer consumption by 2010/11. The full report is available
at the website www.producirconservando.org.ar.
A replenishment rate of N, P, and S extracted by the four main grain
crops (soybean, wheat, corn, and sunflower) was established for each county or
department according to the soil nutrient availability of the main soils of the
area. In high fertility soils, the replenishment rate was usually lower than 100%,
allowing for a decrease in soil nutrient availability from a negative nutrient
balance. In other cases, low fertility areas, the replenishment rate was
increased depending on the crop and nutrient.
Table 2 shows an example of the percentage of replenishment
considered for some counties/departments in different provinces. Table 3 shows
the averages of the estimated N, P, and S replenishment rates in 2002/03 and
the projected N, P, and S replenishment rates for 2010/11 for the four grain
crops. Replenishments of P higher than 100% are estimated for wheat and corn
to cover part of the P removal by double crop soybean.
Table 2. Percentage of replenishment of N, P, and S used to estimate potential
nutrient needs in some counties of Argentina (Oliverio et al., 2004).
Replenishment
County/Department
Province
N
P
S
----- % ----Bahía Blanca
Buenos Aires
75
100
60
Cap. Sarmiento
Buenos Aires
88
100
60
Gral. Alvarado
Buenos Aires
63
100
40
Gualeguay
Entre Ríos
88
100
40
Marcos Juarez
Córdoba
88
100
60
25 de Mayo
Buenos Aires
75
100
60
Venado Tuerto
Santa Fe
88
100
60
Total fertilizer consumption estimated at 2.3 million t in 2003, would
increase by 120% to almost 5.1 million t by 2011. In this projection of 5.1 million
t for 2010/11, cereals and oil crops will account for 4 million t whereas other
crops (fruits, vegetables, forages, and others) would account for 1.1 million t.
The estimation of 5.1 million t considers only increases on N, P, and S
consumption, and it would rise to 5.3 million t if the potential increase of K
fertilizers consumption is considered.
Fig. 4 shows that most of the increase would be attributed to P fertilizers.
The main reason would be that, as soybeans would be the main crop, N
applications could be reduced in relationship to P applications. In fact, the rates
of removal/application are expected to be of 2.1, 1.2, 22.8, and 4.2 for N, P, and
S, respectively (Fig. 5). The removal of N by soybeans is considered at 50%
since biological N fixation could supply 50% of the total crop N needs.
5
The expansion of soybean monoculture raises concern about the
possibilities of soil N replacement. Grasses as cover crops and a higher
proportion of corn and wheat in the rotation could help to improve soil carbon
(C) and N balances among other benefits. Crop-pastures rotations, that used to
be the main rotation in the Pampas, are another possibility to improve soil
organic matter balances and, thus, soil C and N.
Table 3. Percentage of replenishment of N, P, and S in corn, soybean,
sunflower, and wheat estimated for 2002/03 and projected for 2010/11 (Oliverio
et al., 2004).
Replenishment
Crop
Year
N
P
S
----- % ----Corn
Soybean
Sunflower
Wheat
2500
2002/03
55
103
3
2010/11
74
138
25
2002/03
0
19
5
2010/11
0
54
24
2002/03
4
37
3
2010/11
99
100
25
2002/03
77
190
0
2010/11
77
190
25
Others
P fertilizers
N fertilizers
thousand t
2000
1500
1000
500
0
1999
2000
2001
2002
2003
2011
Fig. 4. Annual fertilizer consumption (N, P and other fertilizers) in Argentina,
1999-2003, and estimated consumption for 2010/11. Adapted from data of
Fundación Producir Conservando.
6
NPKS Removal
2000
1500
1078
1000
469
500
288
0
2000
thousand ton
Sunflower
Soybean
Wheat
Corn
2221
thousand ton
NPKS Application
1500
1000
1051
396
500
0
N
P
K
S
N
P
47
69
K
S
Fig. 5. Nutrient removal and application in the four main grain crops of
Argentina estimated for the 2010/11 season. Removal of N in soybean
was reduced by 50% considering supply by biological N fixation. Adapted
from data of Fundación Producir Conservando.
Results of recent field experimentation
Field research has provided strong support for the adoption of fertilization
programs not only because of the agronomic and economic results but also
because it provides to a better soil nutrient balance. Fig. 6 shows a summary of
the results of the Nutrition Network of CREA Southern Santa Fe. Balanced NPS
fertilization has resulted in increases of yield of 3291, 1289, 367, and 166 kg/ha
for corn, wheat, double-cropped soybean, and full-season soybean,
respectively. For a rotation Corn-Soybean-Wheat/Soybean, these results
indicate that the net margin of the NPS treatment over the Control would be of
98 U$/ha. However, if the nutrients extracted from the soil are included in the
costs, the net margin of the NPS treatment would increase to 269 U$/ha.
Data of the corn experiments of the AAPRESID-INPOFOS network in
2003/04 are shown in Fig. 7. There were significant differences among the
fertilized treatments and the Check, but no differences among fertilization
treatments. Seven experiments carried out in northern Buenos Aires and
southern Santa Fe in the last growing season showed an average response of
2121 kg/ha to PS fertilization but no response to K applications (Fig. 8).
Two long term experiments at southeastern Córdoba (V. Gudelj et al.,
EEA INTA Marcos Juárez), provide information about the potential amount of C
that could be incorporated through the residues into the soil (Fig. 9).
Estimations for the Check, NPS rates according to diagnosis (NPS), and NPS
rates according nutrient removal in grains (NPS Rep), show that C supply in the
residues could be 31% to 80% greater with NPS fertilization. The greater input
of C into the soil will allow maintaining a more adequate soil organic matter
balance, and thus, contributing towards the sustainability of the agricultural
ecosystem.
7
Average Yield (kg/ha)
10472
10000
8000
Control
7181
NPS
Fertilizer rates (kg/ha): 260 Urea + 170 MAP + 130 CS
6000
4000
3437
3782 3948
3133
3500
2148
2000
0
Corn (19)
Wheat (16)
Soybean I (6)
Soybean II
(16)
Fig. 6. Average grain yields of corn, wheat, full-season soybean, and doublecropped soybean in the Network CREA Southern Santa Fe. The numbers
between parentheses indicate the number of sites/years for each crop.
MAP is monoammonium phosphate and CS is calcium sulfate.
Corn Yield (kg/ha)
10000
9436
8838
8759
NP
NPS
8752
8945
NPSKMg
NPSKMg
micros
8000
6548
6000
4000
2000
0
Check
NPSK
Fig. 7. Corn yield, average of 11 sites, under different fertilization treatments.
Network AAPRESID-INPOFOS, 2003/04. Argentina.
8
12000
10215
Corn Yield (kg/ha)
10000
10639
11310
11304
PS
PSK
9189
8000
6000
4000
2000
0
Check
S
P
Fig. 8. Corn yields under different P, S and K treatments at seven sites of
northern Buenos Aires and southern Santa Fe in the 2003/04 season. All
treatments were fertilized with 150 kg/ha of N. Source: Prystupa et al.
(2004).
C in residues (kg/ha)
14000
Check
NPS
NPS Rep
12000
10000
8000
6000
4000
2000
0
Don Osvaldo
Los Chañaritos
Fig. 9. Amount of C returned in the residues in a rotation corn-wheat/soybean
under different fertilization treatments in two experiments at southeastern
Córdoba. Site Don Osvaldo is characterized as low soil fertility, Site Los
Chañaritos is characterized as medium soil fertility. NPS is the rate
according to current official recommendations, and NPS Rep is the rate
estimated from nutrient removal in grains. Adapted form data of V. Gudelj
et al. (pers. comm., EEA INTA Marcos Juárez, Córdoba).
9
3650
3753
3652
3085
2801
3000
2222
Wheat yield (kg/ha)
4000
2715
3443
Responses to nutrients other than N, P, and S, have been observed for
specific crops in some areas, i.e. zinc in corn, and boron in sunflower, alfalfa,
wheat, corn and soybean. Fig. 10 shows the results of three years of research
at 9 de Julio (northcentral Buenos Aires) on chloride (Cl) effects in wheat with
responses of 863 and 310 kg/ha without or with the application of fungicides,
respectively. These results agree with those of Diaz Zorita et al. (2003) at
western Buenos Aires.
2000
Without Fungicide
1000
With Fungicide
0
Check
23 kg Cl 46 kg Cl
Cl rate (kg/ha)
69 kg Cl
Fig. 10. Wheat yield with different rates of chloride (Cl) application with or
without fungicide application. Average of three years of field
experimentation of UEEA INTA 9 de Julio, Buenos Aires, Argentina. All
treatments received N, P, and S fertilization.
Summary and conclusions
Grain production in Argentina, mainly at the Pampas Region, has sharply
increased in the last decade. A report of “Fundación Producir Conservando” has
projected a potential production of 100 million t of grain for 2010/11. Current soil
nutrient balances are negative for grain crop production, thus fertilizer
consumption in Argentina should rapidly grow to sustain the goal of 100 million t
of grain. Projections indicate a potential market of 5.3 million t for 2010/11. This
consumption will allow improving replenishment rates of N, P, K, and S from 30
to 47%, 40 to 84%, 2 to 4%, and 15 to 24%, respectively.
Field research has provided strong support for the adoption of fertilization
programs not only because of the agronomic and economic results but also
because of the possibility of providing a better soil nutrient balance. Nitrogen,
phosphorus and sulfur have been characterized as the most deficient nutrients
for grain production in the Pampas and other regions of Argentina, but
responses to other nutrients such as boron, chloride, and zinc have been
10
reported in grain crops. Long term experiments are providing relevant
information on the effects of fertilization management on the sustainability of the
agricultural ecosystem, i.e. improved C incorporation through crop residues and
soil nutrient balances.
References
Andriulo A., J. Galantini and F. Abrego. 1996. Exportación y balance edáfico de nutrientes
luego de 80 años de agricultura continúa. Carpeta de Producción Vegetal. Generalidades.
Información Técnica Nº 147, XIV, 1-10. EEA INTA Pergamino. Buenos Aires, Argentina.
Díaz Zorita M., G. Duarte and M. Barraco. 2004. Effects of chloride fertilization on wheat
(Triticum aestivum L.) productivity in the Sandy Pampas region, Argentina. Agron. J. 96:
939-844.
Prystupa P., F. Salvagiotti, G. Ferraris, F. Gutierrez Boem, J. Elisei and L. Couretot. 2004.
Efecto de la fertilización con fósforo, azufre y potasio en cultivos de maíz en la pampa
ondulada. Informaciones Agronómicas 23:1-4. INPOFOS Cono Sur. Acassuso, Buenos
Aires, Argentina.
García F. 2001. Balance de fósforo en los suelos de la región pampeana. Informaciones
Agronómicas del Cono Sur No. 9 pag. 1-3. INPOFOS Cono Sur, Acassuso, Buenos Aires,
Argentina.
Oliverio G. and G. López. 2002. Potencial y Limitantes de la Producción de Granos y Carnes en
Argentina: Su impacto Económico y Social. Fundación Producir Conservando. Buenos Aires,
Argentina. Available at http://www.producirconservando.org.ar/, verified 4/11/04.
Oliverio G., F. Segovia and G. López. 2004. Fertilizantes para una Argentina de 100 millones
de toneladas”. Fundación “Producir Conservando”. Buenos Aires, Argentina. Available at
http://www.producirconservando.org.ar/, verified 4/11/04.