Establishing a Plant Nutrition Network for the CREA Region in Southern Santa Fé

On-farm field experiments establish as a long-term network in 2000, to evaluate responses to N, P, and S in wheat, soybean, and maize in the southern Santa Fe and Southeastern Cordoba regions. Evolution of soil properties are evaluated periodically in teh different treatments.


08 Feb 2012

2011 Annual Interpretive Summary

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