Given the discussions about a projected shortage of traditional ag lime this fall and potentially into the next few years, we may get more inquiries about pelletized lime products. "So far this fall I have gotten more questions on ag lime versus pel-lime than in the last 3 or 4 falls combined, mostly due to the discussion of shortages of ag lime," says Iowa State University Extension field agronomist Clarke McGrath.
The On-Farm Network, an on-farm research program sponsored by the Iowa Soybean Association, is currently recruiting participants for an interesting research project this fall. They are taking a look at a product farmers ask a lot of questions about, pelletized limestone. Given the discussions about a projected shortage of traditional ag lime this fall and potentially into the next few years, we may get more inquiries about pelletized lime products. "So far this fall I have gotten more questions on ag lime versus pel-lime than in the last 3 or 4 falls combined, mostly due to the discussion of shortages of ag lime," says Iowa State University Extension field agronomist Clarke McGrath.
Both types, regular ag lime and pel-lime, have pros and cons
There has been long running debate about ag lime versus pelletized lime; costs, rates, effective amount of active ingredients and application issues to name a few, he notes. In Iowa, dealers have sold hundreds of thousands of acres worth of both types of lime.
"Both have a fit in Iowa farming systems, both have pros and cons, but we have a lot to learn about them as well," says McGrath. "ISA started some studies this spring and these additional studies planned for this fall will hopefully provide us results that add to our ability to put the right products on the right acres in a few years."
Looking for fields that have been tested and have a low soil pH
The product the On-Farm Network is looking at is SuperCal 98G, a pelletized lime product from Calcium Products. The On-Farm Network is looking for five farmer participants who have recently tested their fields and have documented soil pH values below 6.0—they want low testing fields in which to conduct these tests.
Additional samples will be collected on the selected fields this fall prior to lime application and every year after application to monitor pH change over time. SuperCal 98G pelletized lime will be applied in replicated strip trials at a rate of 800 lbs. per acre on up to 20 acres per trial. If you would like to participate or know a grower interested, contact McGrath or his colleague Aaron Saeugling at email@example.com and firstname.lastname@example.org and they will pass the info along to ISA.
More SCN-resistant soybean varieties for Iowa for 2015
On another crop-related topic, fall is a great time to get a handle on managing Soybean Cyst Nematode by sampling and testing the soil in your fields for the presence of SCN.
A grower recently asked what could have gone wrong in one of his large (and uniform) soybean fields; half of the field yielded over 60 bushels per acre, the other half (a different soybean variety) was barely above 40 bushels per acre. "We discussed a number of possibilities," says McGrath, "and a few things that emerged were:"
• The better yielding variety was SCN resistant
• The lower yielding variety was not SCN resistant
• The grower was unsure if there were any SCN tests ever done on that farm
"SCN may or may not have been a factor, but we eliminated a lot of other possibilities in our analysis," says McGrath. "Our takeaway from the discussion was that a regular testing program for SCN was a good plan for anyone growing soybeans. This also evolved into a short discussion about the number of good SCN resistant varieties on the market these days. ISU's Dr. Greg Tylka and his crew do a great job of testing hundreds of SCN varieties every year."