Quick summary: There was no boost in yield or tissue N from Pivot-Bio additions, however we did observe higher levels of Mn in corn ear leaves with the biofertilizer. Yield may have been limited by something other than N.
To examine Nitrogen (N) contributions from biological fertilizer amendments, Pivot-Bio was added across a range of N-rates (0-330 lbs/acre) in the spring of 2023. The irrigated plots were harvested in October where yields ranged from 50 to 200 bushels per acre (Figure 1). The only statistical difference in yield was 0 N with pivot bio, which was lower than all other treatments. A dry cool May potentially reduced N availability in 2023, and heavy rainfalls and field saturation may have also limited yields. Drone imagery taken during the season will be analyzed at a later date to determine when yield may have become limited.
Although biological amendments are expected to provide additional N to corn, the only differences observed in ear leaf N concentrations (taken at tasseling) was by the actual N-rates (Figure 2a). Nitrogen was lowest at the 0 N-rate, with minor increases until 150 lbs of N, and no benefit from using Pivot-Bio.
No differences were observed for tissue P or K, but S (Figure 2b) also increased with N-rate. Other nutrients that increased with N rate in this study were Zn, Fe, and Cu (Figure 3), with no effects based on additions of Pivot-Bio. Manganese was the only nutrient that increased in the ear leaf when Pivot Bio was added to the starter solution (Figure 3d). This study represents one soil type during one season, and does not cover all environments.
