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.


17 Jan 2008

2007 Annual Interpretive Summary

The Regional Consortium of Agricultural Experimentation (CREA), a farmer organization based in Southern Santa Fe, has collaborated with IPNI to establish a network of field experiments with the objectives of: 1) determining direct and residual responses to N, P, sulfur (S), and where indicated, K, magnesium (Mg), boron (B), copper (Cu), and zinc (Zn); 2) evaluating recommendation methods for N, P, and S fertilization; and 3) identifying the level of deficiency and potential response to nutrients other than N, P, and S. The experiments evaluated check (CK), PS, NS, NP, NPS, and NPS + KMgBCuZn treatments. In 2006/07, five sites within a corn-wheat/soybean rotation (C-W/S), and four sites within a corn-soybean-wheat/soybean rotation (C-S-W/S) were planted to corn.

Soil testing indicated residual effects from N, P, and S fertilization at all sites. Excellent climatic conditions allowed for record corn grain yields which ranged between 5.4 to 10.1 t/ha for the CK and 11.4 to 16.4 t/ha for the NPS treatments. Significant corn yield responses to NPS, NP, NS, N, P, and other nutrients were observed at 2, 6, 3, 1, 1, and 1 sites, respectively. Considering the 31 sites/year over the five corn seasons of the network, corn yields and corn N responses have been significantly related to soil pre-plant nitrate-N availability, and corn yields of 10 t/ha could be obtained with soil nitrate-N levels of 140 to 150 kg/ha (0 to 60 cm). A soil Bray P-1 critical level of 15 mg/kg has been established below which corn P responses are highly probable. For S, sites with soil pre-plant sulfate-S levels below 10 mg/kg generally show corn yield responses greater than 300 kg/ha. Sites will be planted to wheat/soybean in the C-W/S rotation and to full season soybean in the C-S-W/S rotation, in the 2007/08 season. Argentina-12