Interaction of Nitrogen and Flue Gas Desulfurization Sulfur for Production of Corn

This poster was presented at the annual ASA/CSSA/SSSA meetings in Indianapolis, IN in Nov. 2006Nitrogen deficiency in soil often limits corn (Zea mays L.) growth, thus requiring fertilizer N inputs to achieve optimum yields. Nitrogen fertilizer is becoming more expensive and methods are needed to improve N use efficiency. Sulfur deficiency in several crops, including corn, has recently been observed in Ohio. However, little information is available related to the interaction of N and S fertilizers to effect the production of corn. Field experiments were conducted on a silt loam soil at Wooster, Ohio from 2002 to 2005 to test corn responses to the addition of N (seven rates from 0 to 233 kg ha-1) and S (two rates of 0 and 33 kg ha-1) from flue gas desulfurization (FGD) products. Corn grain yields, averaged over 4 years, were increased 7.0% when S was applied. This increase was statistically significant (P < 0.05). A statistically significant interaction effect of N by S was observed in 2004 and 2005 with the low N rates from 0 to 133 kg ha-1 responding better to S than the high N rates. The highest grain yields were reached at the 133 kg N ha-1 application rate with S addition. This suggests that S application can improve N use efficiency and decrease the amount of N required for optimum corn production. Reduced N fertilizer application rates can also help maintain good water quality. Nitrogen, P, K, Mg and S in corn grain were slightly increased by application of 33 kg ha-1 of S when N was applied at rates of 100 and 200 kg ha-1. These results indicate application of N fertilizer with S promoted uptake, by corn plants, of N and other major plant nutrients