Effect of sulfur rate, application method, and source on yield and mineral content of corn

Abstract

Abstract Corn (Zea mays L.) grown on sandy Coastal Plain soils may be subject to sulfur (S) deficiency due to the low levels of available S in the soil. The diagnosis of S deficiency in the field is sometimes ambiguous since mineralization of soil organic matter or root growth into the subsoil may supply adequate S to the crop. Yield response to S fertilizers has been more frequent since incidental additions of S to the soil by air pollution and fertilizer applications have been reduced. This study was conducted to identify S deficiency in corn grown on sandy Coastal Plain soils and to determine the effects of S source, rate and method of application on grain yield. Irrigated corn was grown on Norfolk loamy sand and Tifton loamy sand near Leesburg and Moultrie, Georgia, respectively in 1987. Grain yields were increased with addition of 11 kg S ha‐1 compared to the check treatment. Increased rates of S up to 88 kg ha‐1 did not increase grain yields above the 11 kg ha‐1 rate. There was no difference between banded or broadcast application of (NH4)2SO4 or between elemental S and (NH4)2SO4 as S sources. Earleaf S concentrations of 1.6 g kg‐1 and extractable soil S concentrations of 4.0 to 8.7 mg kg‐1 were associated with S deficiency. Visual symtoms of S deficiency were observed in the check treatments throughout the growing season at both experimental sites. The results indicate that visual symptoms and tissue analysis can be used to identify S deficiency. Extractable soil S may be useful in determining the possible response to S fertilizer especially if the subsoil is sampled.