One of our first visits was with Tecnoagro, a private company that conducts soil tests and make fertilizer recommendations. The soils of the Humid Pampas are very deep and derived from grasslands (similar to the prairie soils of Iowa, Minnesota and Illinois).
The soils in the Humid Pampas of Argentina have high native K values. Soil pH is not a concern in most of the region. In addition, farmers plan to get about half of their nitrogen requirements from the soil. So, farmers here fertilize N, P and S. Research here has shown crop yield increases from fertilizer sulfur. (Research in Kentucky to date does not show yield increases from fertilizer sulfur.)
Summer here is similar to summer in Kentucky, but winter here is more mild... more similar to central Georgia winters. Rainfall in this region is about 1000 mm, which is similar to Kentucky annual rainfall. Like Kentucky, the amount of rainfall is not the problem, but timeliness of that rainfall is often a concern. For the 2009/10 crop, rainfall has been very high. Parts of this region received about 400 to 450 mm in 45 days. Typically, March is a rainy month so farmers here are concerned about getting the crop harvested.
Right now, corn is in the dent stage and about 1/2 milkline. Some of the corn is already at blacklayer (physiological maturity). Full season soybeans are close to the full seed stage while double crop soybeans at the full pod to beginning seed stage. Insects have been very active this year and most fields have been sprayed with an insecticide. Frogeye leaf spot (Cercospora sojina) is in most fields this year and is a relatively new disease for Argentina.