1/3/2022 - By Dr. Tom Reed

Harrell's POLYON® controlled-release fertilizer (CRF) blends have demonstrated value across crops and production systems. However, until recently that value has not been fully appreciated in exceptionally short season crops.

POLYON® and conventional nitrogen sources

Research studies conducted by the University of Florida Institute of Food and Agricultural Sciences have further detailed POLYON® benefits. A spring 2021 rate study compared conventional fertilizer and POLYON® CRF sources of nitrogen on snap beans. On average POLYON® banded treatments yielded 8% greater than the conventional ammonium nitrate treatments across N rates. The current recommended N rate from the University of Florida is 100 lb/ac. In this trial, the 100 lb N/ac treatments of POLYON®, both banded and broadcast-applied, were among the top yielding treatments at both harvest dates and were significantly greater than the 100 lb N/ac rate of conventional, indicating a single POLYON® preplant application was equal to or better than 100 lb N/ac of a conventional source, split into three applications.

POLYON® and leaching

The soil nitrate-nitrogen data suggested the conventional treatments N leached below the root zone during much of this trial and that it appears the POLYON® sources are more likely to maintain higher levels in the root zone, that is available for plant growth throughout the season. Correspondingly, a study in fall 2020 also compared a conventional grower fertilizer program to a single preplant application of a POLYON® blend and revealed soil N content was over four times greater in plots with the POLYON® application than the conventional grower program, after the heavy rainfall. Thus, signifying reduced leaching and environmental impact with the use of POLYON® blend.
The program with University of Florida researchers will continue to evaluate application methods for yield and nutrient efficiency optimization. Harrell's POLYON® blends are engineered to provide nutrients over time at a predictable rate under specified conditions. To find the right POLYON® controlled-release fertilizer product for you, reach out to your Harrell's Rep.