Keeping fertilizer expenses in check

BLOOMINGTON, Ill. — With season-average corn and soybeans prices in the new year projected to remain at current levels, agronomists recommend prioritizing nutrient management to improve the bottom line.

“You can’t farm without buying seed. If you don’t buy herbicides, you’re going to have a mess, too. So, you have some things that you have to spend money on,” said Tim Smith, Cropsmith president and managing agronomist.

“If you still have dry fertilizer decisions to make and you’ve got soil test data to look at, this is a perfect time to evaluate where there’s high-testing sites that are not going to respond to fertilizer, also low-testing sites that would be prioritized to reduce yield losses,” said John Jones, University of Illinois assistant professor of agronomy and U of I Extension soil fertility specialist.

During a break at the Illinois Soybean Association’s recent “Soil Test Interpretation for Profitable Management” program, Smith and Jones stressed the need to focus on what the soil offers from a nutrient standpoint.

“You can still sample in the spring if you don’t have soil test data to work off of. For phosphorus and potassium, I would recommend considering when was your last soil test, what you’re looking at, and making sure you have accurate removal and yield data to estimate any maintenance rates,” Jones said.

“There’s a lot of fertility in our soil. A soil test gives us an opportunity to measure that and know whether we can cut back on that input when times are tough. And it’s directly related to, if I’m not getting a response to that fertilizer at this time, should I be spending that money? And maybe times are good in a few years and you say, OK, I’m going to spend some more money at that time and build up the soil,” Smith added.

“We treat our soils like they’re a bank account as far as fertility and it’s not really good. If it’s a bank account, it’s the worst bank account you could ever have. Your interest would just evaporate and those type of things. So, there are good opportunities to really moderate or cut out some fertility, especially if you’ve been putting good amounts of fertilizer on the past.”

Best ROI

Jones noted soil testing offers the best return-on-investment in farming.

“Regular soil testing within your rotation makes a lot of sense. Many are on a four-year rotation of soil testing, we’ll say, every two corn and soybean years. I would say if you’re getting to a point where you’re in high-yielding scenarios where you have high removal rates, if you can snap that back to a two-year rotation for soil testing, I think there’s a benefit there on the cost savings that you may find,” Jones said.

4 Rs

Farmers may feel it’s too risky to cut back on nitrogen applications in times of tight budgets, but university research indicates too much “insurance” nitrogen is sometimes being applied.

Smith recommends implementing the four Rs — right source, matches fertilizer to crop needs; right rate, matches amount of fertilizer type crop needs; right time, makes nutrients available when crop needs them; and right place, keep nutrients where crops can use them.

“There’s opportunity there to use the 4Rs, do it at a better time and doing placement with good forms that are protected. You can grow just as good of crop by really making good decisions around nitrogen,” Smith said.

“There’s such a big opportunity to improve how we manage nitrogen, which also reduces cost. Now, you may have to do a little more work to get there, a little more thought, maybe it’s some investments in equipment, but it should be well worth it to do those type of things.”

Nitrogen Rate Tool

Research-based Maximum Return to Nitrogen guidelines are available at no cost for producers. The online calculator at cornratecalc.org is specific for various regions in Illinois, Indiana and other Corn Belt states.

“I would suggest looking at the corn N rate calculator website, an application that we provide and update every year with nitrogen guidelines for Illinois. Those focus on economic optimum nitrogen rates, which are usually about one to two bushels off of the maximum yield that we can achieve in a study. We’ve essentially let the last pound of nitrogen pay for itself with a bushel gain. So, we’re leaning to both an agronomic and an economic optimum,” Jones said.

“MRTN is a good starting point, but it’s only a starting point. It’s a nice average for areas of the state, but you have to look at your own farm and see what you can do,” Smith added.

“Farmers are putting insurance nitrogen on top of MRTN, and that’s really not necessary on most of the farms. But if you do some simple things where you put a little more, a little less in different areas of your farm over time, you get a pretty good idea of where you need to be.”

Prioritize Nutrients

“When there are challenging margins, we should be thinking about nutrients that we prioritize as something that is important. For example, we have a lot of data that shows if we’re low enough in soil test K, our internal nitrogen use efficiency crashes. Make sure you identify what’s potentially limiting and really knowing that you’re going to get an economic response to that,” Jones said.

“Soil testing has always been important. We do pH, P, K testing, and nitrogen soil testing is something I’d like to see us work more on in the future. I think that there’s some opportunity for that in the future, but I think people aren’t ready for that yet, but I think we’re getting there,” Smith added.