Wednesday, November 7, 2007
296-22

Rice Grain Yield and Tissue Response to Zinc Fertilizer Source and Rate.

Timothy Walker, Mississippi State University, Delta Research & Ext. Center, PO Box 197, Stoneville, MS 38776, Jason Bond, Louisiana State Univ.-Rice Res. Stn, P.O. Box 197, Stoneville, MS 38776, and Jason M. Satterfield, Delta Research and Extension Center, Mississippi State University, 82 Stoneville Road, Stoneville, MS 38776.

Soil pH greatly affects mobility and availability of Zn fertilizer.  Fields with historical rice production are subject to elevated soil pH (>6.0) due to large concentrations of Ca- and Mg-bicarbonates in irrigation water.  This factor, in addition to the adoption of land-leveling for irrigation efficiency, has led to an increase in Zn-deficient rice in the midsouthern USA rice production region.  Experiments were implemented in 2007 to evaluate rice grain and tissue response to Zn fertilizer sources and rates.  Zn treatments consisted of foliar and soil-applied (granular) sources.  Foliar sources were Zn-EDTA and Zn-Citrate at application rates of 0.56, 1.12, and 2.24 kg Zn ha-1, whereas granular sources were Zn-sulfate and a combination of Zn-sulfate and Zn-lignosulfate at application rates of 2.8, 5.6, and 11.2 kg Zn ha-1.  Foliar applications were made to rice at the 5-leaf growth stage, which is approximately five to seven days prior to flood establishment.  Granular sources were applied to 1-leaf rice, which is approximately 21 to 25 days prior to flood establishment.  Zinc extractions from Lancaster, Mehlich-3, and DTPA soil test methods will be conducted on soil samples collected from the zero Zn plots and correlated to plant Zn uptake and grain yield.