Americas and Oceania Group - International Plant Nutrition Institute

Chile
Bolivia
Paraguay
Uruguay
Argentina
Americas and Oceania Group
Latin America–Southern Cone: Dr. Fernando García
Argentina
The Crop Nutrition Network in the CREA Region of Southern Santa Fe
Project Leader: Belisario Alvarez de Toledo, Regional Consortium of Agricultural Experimentation (AACREA)
Sarmiento, Buenos Aires, Argentina. E-mail: athomas@canalsnet.com.ar
Project Cooperator: Alejandro Thomas
The Regional Consortium of Agricultural Experimentation (CREA), a farmer organization based in
Southern Santa Fe, has established a network of field experiments with the objectives of: 1) determining
direct and residual responses to N, P, S, and where indicated, to K, Mg, B, Cu, and Zn, 2) evaluating
recommendation methods for N, P, and S fertilization, 3) identifying the level of deficiency and potential
response to nutrients other than N, P, and S, and 4) evaluating the evolution of soil quality under contrasting
nutrient management. In 2010-11, two sites within a corn-wheat/soybean (C-W/S) rotation were planted to
maize, and four sites within a corn-soybean-wheat/soybean (C-S-W/S) rotation were planted to full-season
soybeans.
Excellent climatic conditions at the two maize experiments allowed for high yields. Yield responses to N,
P, and S were significant at both sites (average of 6,465 kg/ha, +132%), and responses to nutrients other than
NPS were significant at the Balducci site (647 kg/ha, +8%). Soybean yields averaged from 3,400 to 5,200 kg/
ha in the four experiments. Responses to N, P, and S were significant at three sites, with average responses of
364, 488, and 448 kg/ha to N, P, and S, respectively. The combined response to NPS at the four sites averaged
1088 kg/ha (+33%).
Considering the 11 seasons with 40 sites under corn, 33 sites under wheat, 52 sites under full-season and
double cropped soybean, significant relationships were established between Bray 1 P and P responses, with
critical levels between 12 and 20 ppm for the three crops below which P responses are highly probable. Also,
significant relationships were established between grain yield and soil N supply as predicted by soil nitrate-N
measured at sowing + fertilizer N rate, for maize and wheat.
The analysis of the first years of the Nutrition Network has shown that adequate NPS management
increased grain yields, contributed to improved water use efficiency, tended to increase soil organic matter,
decreased soil pH, allowed for soil P build-up, and increased profits. Sites will be planted to wheat-soybeans
in both rotations (C-W/S and C-S-W/S) during the 2011-12 season. Argentina-12
Long-term Nutrient Management Network for Southern Buenos Aires Province
Project Leaders: Fernando García, IPNI Southern Cone and Ernesto Caracoche, ASP Southern Division, Acassuso,
Buenos Aires. E-mail: fgarcia@ipni.net
In 2007-08, IPNI and Agroservicios Pampeanos (ASP) established a network of field experiments with
the objectives of: 1) determining direct and residual responses to N, P, and S, 2) evaluating recommendation
methods for N, P, and S fertilization, and 3) identifying the level of deficiency and potential responses to
nutrients other than N, P, and S, such as K, Mg, B, Cl - , Cu, and Zn. Four sites were planted to wheat at
Balcarce, Pieres, Tandil, and Tres Arroyos during the 2010/11 growing season.
Excellent climatic conditions during the 2010-11 growing season allowed high grain yields to be reached.
Wheat check yields varied from 3,989 to 5,082 kg/ha, and NPS fertilized yields varied from 5,158 to 8,167
kg/ha. Responses were significant to NP at Balcarce (+2,797 kg/ha, +63%), Pieres (+1,492 kg/ha, +26%), and
Tres Arroyos (+3,126 kg/ha, +61%); and to P at Tandil (+1,552 kg/ha, +43%). Grain yield responses were
related to low soil nitrate-N, and Bray-1 P levels, and good weather conditions. No responses were observed
to nutrients other than N, P, and S. These sites will be planted to full season soybean during the fifth season of
evaluation in 2011-12. Argentina-27
IPNI Interpretive Summaries 49