If you plan to trim your burgeoning '08 input budget by skipping soil testing, or by trimming fertilizer applications without having up-to-date soil test results to rely upon, you may be doing the proverbial 'cut off your nose to spite your face,' move. Jim Camberato, Purdue University Extension soil fertility specialist, says soil testing is very important this year.
If you've built soil fertility in the past and are at high or even drawdown levels, which means university recommendations would call for only maintenance or even no fertilizer application for next year, then '08 might be a season to skip phosphorus and potassium application, he notes. However, that assumes that the price of the fertilizer will come down at some point in the future when you finally do need to apply again.
You shouldn't expect a yield increase next year from fertilizer applied this fall or next spring for the '08 crop if test levels are high or in the drawdown range, he notes. That may factor into your buying decisions for '08.But if your soils test low for P and/or K, applying fertilizer should pay in terms of a yield increase yet next year.
Greg Bossaer, White County Extension ag educator, says he believes most producers in his area are already doing a good job managing soil fertility. That means they're keeping current with an accurate soil testing program, and following other basic application rules.
One move he does anticipate from some people who normally apply fertilizer for the next two seasons in a field at one time is to just apply enough P and K for one season now and then apply more next year.
None of Camberato's advice makes sense unless you have an accurate soil test to go by, he notes. That means a relatively current test, and one done accurately. Whether grid or sampling by soil type is best may differ from area to area and be up for debate, but there's no debate that having either one is highly preferable to having no information. Then you're just guessing, he says.
One problem with postponing fertilizer applications in fields where most samples are high is that some low-testing areas might get missed. Even very good soil tests don't always pick up every low testing area within a field. Low testing areas could be expected to deliver an immediate payback in terms of increased yield for either corn or soybeans in the next crop season.
If you have questions about fall fertilization and the possibility of applying less fertilizer on some fields this year, consult with your local Extension ag educator. These decisions should be made on a field-by-field basis, Camberato adds.