Extension Update by Jenny Rees

Farm Bill ARC-IC: Unless one has a field that tends to get hit with lower yields compared to county average every year, I’m unsure that ARC-IC is a fit for many farmers in this part of the State. For the 2021 decision, one would need to expect 2021 yield to be significantly less than county average yields. So if your field(s) are typically near or above county average yields, it’s perhaps not the wisest decision.

Lawn Care: The beautiful weather is a great opportunity to rake lawns, remove leaves from lawns, and dormant overseed grass in thin spots. Dormant seeding provides an opportunity for seed to grow when soil temperatures warm and spring rains come. Prepare areas to overseed by hand raking small areas to remove dead growth and loosen the soil surface. Large areas can be heavily aerated. It’s best to only power rake if there’s a thatch layer of ½” or more present. Overseed Kentucky bluegrass at 1-2 lbs/1000 square feet and tall fescue at 4-6 lbs/1000 square feet. Also, it’s too early to apply fertilizer and herbicides to lawns.

Solar Electric Questions: Will share more regarding a free webinar series next week to be held from Mar. 30-Apr. 8. If you have specific solar-related questions right now, please direct them to John Hay, Nebraska Extension Educator at 402-472-0408 or jhay2@unl.edu.

Nitrogen Rate and Timing Studies: An article written by Dr. Charlie Wortmann and colleagues shared, “Partial Factor Productivity (PFP) is commonly expressed as yield per unit input, e.g. bushels of corn per pound of fertilizer N applied (bu/lb N). PFP can be adapted to units of nutrient removed in grain harvest to units of nutrient applied, such as corn N harvested relative to fertilizer N applied (PFP_N, lb/lb).” Advances in corn genetics and changes in farmers’ management practices have resulted in more pounds of grain produced for every pound of nitrogen applied. Dr. Richard Ferguson shared, “The average PFP of fertilizer N for corn in Nebraska was estimated to average 1.16 bu/lb N in 2012 compared to 0.57 bu/lb N in 1965. This represents a doubling in PFP for fertilizer N applied to corn. The trend of increase was linear from 1965 to 2012. Assuming a grain N concentration of 1.2% at 84.5% dry wt. or 0.67 lb N/bu, the PFP_N converts to 0.79 lb of grain N per lb of fertilizer N applied in 2012 compared with 0.38 lb/lb in 1965.” That’s quite an increase in nitrogen use efficiency!

Another way farmers have been looking to increase nitrogen use efficiency is to compare nitrogen rates and timing of the fertilizer applications. We’ve had some on-farm research studies recently look at sidedress applications using either the UNL equation/Maize N model or industry models such as Climate Field View and Granular. In all these studies, the recommended rate was compared to rates that were at least 30 or 50 pounds over and under the recommended rate. In 2020, there were two nitrogen rate and timing studies in the area partially sponsored by the UBBNRD. A York County study found no yield differences between applications of spring anhydrous of 135, 185, and 235 lbs/ac. The same farmer also did a nitrogen rate X timing study in Hamilton County. He compared Fall vs. Spring vs. Split application rates of anhydrous + UAN of 205 vs. 255 lb/ac for each timing. There were no yield differences with any of the timings and rates. Take homes: In none of the studies did the addition of 30-50 lbs N/ac above the recommended rate increase the yield statistically. A few of these studies also compared side-dress applications vs. pre-plant alone. One situation resulted in a statistically lower yield with pre-plant alone while the others resulted in no yield differences. I’ve compiled these results in a table at http://jenreesources.com.

These nitrogen rate and timing studies could provide farmers a way to assess for their own operations. I’ve mentioned the precision nutrient management studies (https://go.unl.edu/4rvw) for several months. If you weren’t sure if it could apply to your situation, I was told that those don’t have to be precision nutrient applied. So, if you’re interested, please let me know and we can work out the details. There is a $1300 stipend for that specific study. There’s also up to $300 reimbursement from UBBNRD for water quality related studies. I’m currently working through on-farm research protocols for 2021. If you have a production and/or product-related question you want to test on your own farm, please contact me or your local Extension educator and we’d be happy to help you set up a study!