Impact of Land Application of a Hydrocarbon Stream Desulfurization Waste Product in Winter Canola.

Abstract Surface disposal by land application could provide a cost-effective and environmentally sound disposal method for spent Liquid SulfurTrap™ (LST), while also providing plant available potassium (K) and sulfur (S) to agricultural crops. This study was conducted to determine the effects of land application of LST on grain yield and grain quality in winter canola. The effects of material, application rate, and application timing were investigated using a replicated randomized complete block design at sites in Stillwater and Chickasha, OK on Port silt loam (fine-silty, mixed superactive, thermic Cumulic Haplustoll) and Dale silt loam (fine-silty, mixed, superactive, thermic Pachic Haplustoll) respectively. Treatments were applied at planting and during growth stage 3 with a pressurized CO2 backpack sprayer at rates of 5, 10, 20 gal-ac-1. NDVI measurements were collected with a GreenSeeker™ GS-1 sensor during growth stage 3. Main and interaction effects were analyzed using ANOVA and Tukey HSD methods in R version 3.3. In 2016, the NDVI response varied significantly by location. At Stillwater, application of spent LST caused an increase in NDVI at the 10 gal-ac-1 rate, and a decrease at the 20 gal-ac-1 rate relative to potash + ammonium sulfate (PAS) treatments at ?=0.05 significance level. At Chickasha, application of spent LST did not cause a significant difference in NDVI when compared to PAS treatments, but were significantly lower than the unfertilized check at ? =0.05 significance level. Response by application timing was significant at both sites, with top-dress applications yielding significantly higher NDVI than treatments applied at planting. Keywords: land-application, liming potential, Liquid SulfurTrap, potassium, sulfur, winter canola 02