FS On-Farm Discovery™ is the way to address crop production questions at the farm-gate. With so many growing environment differences, aggregated research data across even a small geography can merely imply if a practice may work on your particular acres. The FS On-Farm Discovery program addresses your questions, in your fields, using your technology and data, moving agriculture into the last half of this decade.
Spring provides a prime opportunity to look for a sulfur response to corn and/or soybeans. The 2014 growing season, coupled with a cool, wet 2015 spring (so far) suggests that residual concentration of sulfur may be low. If this is the case, an application of 15-20 pounds of sulfur is a test protocol within the FS On-Farm Discovery program. If spring, dry fertilizer will still be applied or if you would like to try a split field On-Farm Discovery trial using dry products consider using ammonium sulfate or calcium sulfate. Sulfur is available in a liquid form as ammonium thiosulfate.
Fields most likely to respond to 20 lbs S:
1. Fields with less than 3% organic matter
2. Long-term no-till
3. Well drained soils or poorly drained soils with sub-surface tiling
4. Coarse-textured soils (significant sand)
5. No coal-fired power plants close by
6. No history of significant manure or bi-solid applications
Ammonium Sulfate:
21% Nitrogen, 24% Sulfur (15 lbs S = 63 lbs AMS)
Calcium sulfate is available in at least two forms:
Sulf4R-Plus: 21% Calcium, 17% Sulfur (15 lbs S = 88 lbs Sulf4R-Plus)
High Cal SO4: 21% Calcium, 17% Sulfur (15 lbs S = 88 lbs High Cal SO4)
Ammonium Thiosulfate (ATS):
12% Nitrogen, 26% Sulfur (15 lbs = 5.2 gal. ATS)
Note assumption: ATS weighs 11.04 lbs/gal.
TWO OPTIONS FOR PROJECT SET UP
1. Split Field. Identify a field that meets most of the above criteria and determine the sulfur source that is most convenient. Apply 15 - 20 lbs of sulfur to the selected part of the field making sure there is a record of where the sulfur was applied. Review the yield map at harvest to determine any yield response to the treatment. Weigh wagon yield determination can also be made from strips close to where the treatment ends in the field (with and without sulfur strip comparisons).
2. Multiple Strip Comparisons. Make a sulfur application across the field every-other-pass. Make sure the application passes are geo-referenced (generate an as-applied map). Share your harvest data with your FS Crop Specialist and FS Precision Farming Specialist who will mine the data to extract yield from each with sulfur and without sulfur strips.