Sulochana Dhital, 052 Agricultural Hall, Oklahoma State University, Stillwater, OK, Jeremiah L. Mullock, Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, William R. Raun, 044 N Agricultural Hall, Oklahoma State University, Stillwater, OK and Bee Khim Chim, 2923 Medary Avenue, USDA-ARS, Brookings, SD
Optimum use of nitrogen (N) is a key component in improving wheat grain yield and quality. The combined effect of other nutrients with N can have a positive impact on crop production. Using sulfur (S) and chloride (Cl) in wheat and other cereals has received increased attention in recent years. Foliar S and Cl can assist in optimizing wheat yield and total N, especially in sandy soils with low organic matter where deficiencies are expected. Winter wheat studies were conducted for 3 site-years at Lake Carl Blackwell (LCB) and Lahoma (LAH) in the fall of 2011 and 2012 to evaluate the effect of flag leaf applied foliar N, S and Cl on winter wheat grain yield and grain N. Two N rates, 10 and 20 kg N ha-1, as urea triazone (N-SURE, 28-0-0) and urea ammonium nitrate (UAN, 28-0-0) were foliar applied. Treatments included foliar application of gypsum (6 kg S ha-1) and calcium chloride at a rate of 10 kg Cl ha-1applied with the help of CO2 backpack sprayer. Results showed total grain N increased with increasing preplant N rate at LCB and LAH. With increasing preplant N, a linear increase in yield was observed at LAH and a quadratic increase in yield at LCB. There was no response to foliar N, Cl and S at both locations. This study indicated that S and Cl fertilization did not increase yield and protein.