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

Lollato, Romulo Pisa

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 amendment strategies for winter wheat production. The effects of broadcast agricultural lime (2.25 or 4.50 Mg ECCE ha-1), banded pelletized lime (225 or 450 kg ha-1 yr-1), and banded P fertilizer (28 or 56 kg ha-1 yr-1) on bulk soil pH, aluminum saturation (Alsat), pH change in the soil profile, wheat vegetative development, plant population uniformity, and grain yield, were investigated during three growing seasons in a Grandfield Fine Sandy Loam and a Grant Silt Loam with initial soil pH of 4.8 and 4.9 at Altus and Waukomis, OK. Broadcast agricultural lime at 4.50 Mg ha-1 increased soil pH by one unit and decreased Alsat by 98% at Waukomis. Neither banded pelletized lime nor P fertilizer affected these parameters in either location. 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 profile. In-furrow P fertilizer increased vegetative growth and plant population homogeneity in all years of the study at Waukomis; 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 treatment, probably due to low soil Alsat. When broadcast lime costs were amortized over five years, 2.25 Mg ECCE ha-1 and the control resulted in the highest net returns among treatments. Results indicate that banded P fertilizer or broadcast agricultural lime can increase early-season wheat growth and population uniformity in a low-pH soil, but this increase in vegetative growth might not result grain yields significantly higher than the control when Alsat is lower than 10%.