299-9 Sulfur Cycling In a Wheat, Double Crop Soybean Rotation In Southwest Indiana.



Wednesday, October 19, 2011
Henry Gonzalez Convention Center, Hall C, Street Level

Stephen Maloney, James Camberato and Shaun Casteel, Agronomy, Purdue University, West Lafayette, IN
Sulfur (S) is often an overlooked macronutrient in today’s agronomic cropping systems especially for cool season crops. The objective of this study was to determine optimum rates of nitrogen (N) and S in a field low in S. The field was located near Vincennes Indiana on an Ade loamy fine sand (Coarse-loamy, mixed, superactive, mesic Lamellic Argiudoll). The study was initiated with winter wheat in 2009-10 growing season followed by double-crop soybean in 2010. Experimental design was a 4 x 5 factorial with 4 replications.  Treatments were arranged in a randomized complete block design with 4 S rates of 0, 17, 34, and 50 kg S/ha and 5 N rates of 0, 45, 78, 112, and 146 kg N/ha. Biomass, grain yield, and seed mass were measured for each crop. Plant and seed tissues were analyzed for N and S. Soil samples to a depth of 90 cm in 15-cm increments were analyzed for the movement and concentration of nitrate, sulfate, and ammonium. In wheat, tissue concentrations at Feekes 6 for 17 kg S/ha and 78 kg N/ha correlated well with maximum yield and biomass production. Increased disease severity and lodging were noted at the higher N and S rates. At first bloom, soybean plant tissue was low in S following the low S applications to wheat.  However, soybean yields showed no clear relationship with the applications of N and S in wheat. Additional study results will be provided.
See more from this Division: Canadian Society of Soil Science
See more from this Session: Crop Responses, New Management Strategies, and Improved Methods for Assessing Sulfur Needs I