Dr. Jarrod T. Hardke
ARKANSAS
Skimp Wisely
It seems as though we’re in a perpetual cycle of guessing how far we can reduce our inputs. Fertility is always in the mix of this conversation, and we all know it can be a dangerous topic area.
Nitrogen (N) is most important for rice, so let’s tackle it first. At this stage, you’re likely comfortable with your N rate strategy. Following the law of diminishing returns, the more units of N you apply, the less your return on those units. So, while it may be a minor reduction, reducing your pre-flood N by 5 lbs.-10 lbs. per acre could save you a few dollars and not really change your yield outcome. Treat pre-flood urea with an NBPT product — it’s some of the cheapest insurance we have for N efficiency.
For varieties, do not modify the mid-season rate of 100 lbs. urea (46 lbs. N). For hybrids, stick with the 65 lbs. urea (30 lbs. N) late boot N rate. Some have been applying 100 lbs. urea at late boot on hybrid, but most of our work indicates the additional N isn’t worth it at that timing.
Phosphorus (P) in rice is a dangerous place to skimp, especially on high pH soils. We can reduce our P rates, but generally, we need to apply something, and I prefer a minimum of 30 lbs. P2O5 for rice. Attempting to skip P entirely is dangerous due to a limited window for correction if we’re wrong — we have to identify a deficiency and correct it before reproductive growth to get our yield back, and we can’t always do that.
Potassium (K) is needed in large quantities for rice. The upside of K is that we have a very large window in-season to correct an issue if we fall short. While we prefer not to deal with a shortfall, at least we know we have some margin for error. It’s good to consider 60 lbs. K2O as a baseline rate on soils where K is needed. If reducing rates, consider tissue sampling after panicle initiation to check for adequate K concentrations.
Zinc (Zn) isn’t cheap, but it’s much cheaper to correct upfront than it is to deal with in-season. Go with the soil-test recommended rate for Zn issues. While not a replacement for proper Zn fertilization, Zn seed treatments can help early in the season. It’s preferred to use Zn Oxide-based seed treatments that provide 0.25 lbs.-0.5 lbs. Zn per 100 lbs. of seed. Some EDTA chelated Zn seed treatment formulations are easier to apply on seed but contain much lower Zn rates, and, if applied at the higher end of labeled rates, can cause problems with root and shoot growth of rice.
Proceed with caution on the fertility front in 2026. Small savings can add up, but chasing big savings may not be worth the penalty from weaker areas of the field that are under-fertilized. Also note that if growing row rice, we generally don’t recommend reducing fertility rates below soil-test recommendations due to the upland environment. Good luck in 2026, and let us know if we can help.
Dr. Jarrod T. Hardke
ARKANSAS