TIMING SULFUR APPLICATIONS FOR CORN (ZEA-MAYS L) PRODUCTION ON IRRIGATED SANDY SOIL

The importance of sulfur (S) for corn (Zea mays L.) production on sandy soils has been noted for a number of years. Yet, there has been no extensive evaluation of the timing of S applications on com production in these specific situations. This study was conducted for the purpose of measuring the effect of split applications of fertilizer S on com grown on irrigated sandy soils. The study was conducted in 1985 and 1986. Four rates of fertilizer S (0, 6.5, 13, and 26 kg/ha) were combined with six times of application schemes in a randomized complete block design with four replications. Granular gypsum was used as the source of S. Corn responded to the use of fertilizer S in 1986 only. Time of application had no significant effect on yield in either year. There were no advantages to the use of split applications. The S concentration in the ear leaf tissue at silking was affected by both rate and time of S application at each experimental site. The current recommendation is to apply fertilizer S, when needed, in a starter fertilizer at planting. The results of this study indicate that there is no need to change this recommendation.