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.


23 May 2003

2002 Annual Interpretive Summary

The AACREA region of southern Santa Fe, with the support of local industry, has established a network of field experiments to: i) determine direct and residual responses to nitrogen (N), phosphorus (P), sulfur (S), and other nutrients such as potassium (K), magnesium (Mg), boron (B), copper (Cu), and zinc (Zn); ii) evaluate recommendation methods for N, P, and S fertilization; and iii) evaluate deficiencies and potential responses to nutrients other than N, P, and S.

Five experimental sites were planted to wheat/soybeans (full rotation: corn-wheat/soybeans), and six sites to full season soybeans (full rotation: corn-soybeans-wheat/soybeans). In wheat, significant responses to N were found at two sites, and to P at four sites. Nitrogen responses were related to low soil nitrate-N availability at planting (less than 60 kg/ha nitrate-N at 0 to 60 cm) and P responses were related to low Bray P-1 test levels (less than 15 mg/kg). For double cropped soybeans, one site showed significant responses to P and three sites responded to S. Sulfur responsive sites had soil sulfate-S lower than 10 mg/kg at planting. In full season soybeans, only one of the six sites showed significant responses to PS fertilization. In 2002/03, the experiments will either be planted to corn or to wheat/soybeans.

Farmers in the CREA groups of southern Santa Fe grow approximately 185,000 ha of annual crops within an agricultural area of approximately 600,000 ha where they are leading farmers. ARGENTINA-12