New information for explaining how humic products benefit crops

September 27, 2022 from 1:00 pm to 1:45 pm

Speaker: Dan Olk and Dana Dinnes, USDA-ARS National Laboratory for Agriculture and the Environment, Ames, IA

In a Central Iowa field experiment, corn grain yield and stover biomass increased predictably with larger nitrogen (N) fertilizer rates. Addition of a humic product enhanced corn responses at higher N rates, enabling greater N use efficiency. But at the lowest N rates, the humic product caused a loss of grain yield. This trend, together with other results from our long-term field studies, indicates that humic products can enhance crop growth through means not involving nutrient availability.