Agronomic and Economic Response of Hard Red Winter Wheat to Multiple Liming and Fertilization Strategies.

Application of agricultural lime is the most frequently recommended method for managing low soil pH; however, in-furrow phosphorus (P) fertilizer or pelletized lime are also commonly used to ameliorate soil acidity. The objectives of this study were to evaluate three soil acidity amelioration strategies for winter wheat production. The effects of broadcast agricultural lime (2.24 and 4.48 Mg ha^-1), banded pelletized lime (224 and 448 kg ha^-1 yr^-1), and banded P fertilizer (28 and 56 kg ha^-1 yr^-1) on bulk soil pH, aluminum saturation (Al_sat), spatial distribution of pH change in the soil profile, wheat vegetative development, population uniformity, and grain yield, were investigated during the 2009-10, 2010-11, and 2011-12 growing seasons at Waukomis, OK. The soil was a Grant Silt Loam with an initial soil pH of 4.9. Broadcast agricultural lime at 4.48 Mg ha^-1 increased soil pH by one unit and decreased Al_sat by 98%. Neither banded pelletized lime nor P fertilizer affected these parameters significantly. Spatial changes in soil pH caused by banded pelletized lime were restricted to the region surrounding the pellet, while broadcast agricultural lime increased soil pH throughout the incorporated depth. In-furrow P fertilizer significantly increased vegetative growth and plant population homogeneity in all years of the study; broadcast lime provided similar results in 2010-11 when low soil pH effects on crop growth were more apparent due to severe drought. Wheat grain yield was not affected by any treatment evaluated in this study, which was probably due to low soil Al_sat. None of the strategies resulted in a greater net economic return than the control; however, when lime costs were amortized over 5-yr, net returns were similar. Results indicate that in-furrow application of triple superphosphate or broadcast agricultural lime increase early-season wheat growth and population uniformity in a low-pH soil, but this increase in vegetative growth might not result in increased grain yields when Al_sat is below 10%.