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.
IPNI-2000-ARG-12
26 Dec 2009
2009 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; and 3) identifying the level of deficiency and potential response to nutrients other than N, P, and S. In 2008/09, two sites within a corn-wheat/soybean (C-W/S) rotation were planted to corn, and four sites within a corn-soybean-wheat/soybean (C-S-W/S) rotation were planted to wheat/soybean..
Climatic conditions at the two corn experiments were better than the whole Pampas region and did allow for high yields. Yield responses to NPS were significant at both sites, and responses to nutrients other than NPS were significant at one site. Considering the eight seasons and 34 sites under corn, significant relationships were established between grain yield and soil N supply as predicted by soil nitrate-N measured at sowing + fertilizer N rate. A critical level of 15 ppm Bray 1 P has been established below which corn P responses are highly probable. Wheat experiments were highly affected by severe drought. However, the relative responses to N, P, and S were similar to previous seasons as average responses to P and NP were 400 kg/ha (+25%) and 900 kg/ha (+57%). Considering the eight seasons and 31 sites under wheat, significant relationships were established between grain yield and soil N supply as predicted by soil nitrate-N measured at sowing + fertilizer N rate, N levels of 130 to 140 kg/ha allowed for grain yields of 4,000 kg/ha. A critical level of 15 to 20 ppm Bray 1 P has been established below which wheat P responses are highly probable. Double-cropped soybean yields were also affected by the severe drought and responses to N, P, and S averaged 168, 181, and 87 kg/ha. Considering the 35 sites under soybean during eight seasons, a critical level of 12 ppm Bray 1 P has been established below which soybean P responses are highly probable.
Sites will be planted to wheat/soybean in the C-W/S rotation and to corn in the C-S-W/S rotation during the 2009/10 season. Argentina-12