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.


22 Dec 2003

2003 Annual Interpretive Summary

The Regional Consortium of Agricultural Experimentation (CREA), a farmers’ organization based in Southern Santa Fe, is collaborating with INPOFOS Southern Cone with support from AgroServicios Pampeanos to establish a network of field experiments. The objectives are: 1) determine direct and residual responses to nitrogen (N), phosphorus (P), sulfur (S), and where indicated, potassium (K), magnesium (Mg), boron (B), copper (Cu), and zinc (Zn); 2) evaluate recommendation methods for N, P, and S fertilization; and 3) identify the level of deficiency and potential response to nutrients other than N, P, and S. The six fertilizer treatments are: 1) Check, 2) PS, 3) NS, 4) NP, 5) NPS, and 6) NPS + KMgBCuZn. In 2002/03, five sites were planted to corn (rotation corn-wheat/soybeans), and six sites to wheat/soybean (rotation corn-soybean-wheat/soybean).

Corn: Significant responses to N were found at all five sites, to P at two sites, and to S at one site. These responses were related to low soil nitrate-N (less than 60 kg/ha, 0 to 60 cm depth), low soil Bray P (less than 15 to 16 parts per million [ppm]), and low sulfate-S (less than 10 ppm, 0 to 20 cm depth) availability at planting. The average yield response to NPS across all five sites was 4,062 kg/ha, a 58% increment over the Check.

Wheat: Weather and disease pressure affected nutrient responses. Responses were significant for N at one site, for P at three sites, for S at one site, and for the other nutrients at one site. The average yield response to NPS for the six sites was 502 kg/ha, a 26% increment over the Check.

Soybean: Excellent weather resulted in high yields for the doublecropped soybean crops. Five of the six sites showed significant responses to PS applied in the previous wheat crop. Application of PS in wheat increased doublecropped soybean yields by 932 kg/ha, a 29% increment compared to the Check. Argentina-12