Title: Soil test and bermudagrass forage yield responses to animal waste and FGD gypsum ammendments Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 31, 2014
Publication Date: N/A
Technical Abstract: Knowledge of soil and plant responses to animal or industrial byproducts is needed for effective use of these potential amendments on reclaimed mine soil. This study compared seven treatments of 11.2 Mg ha-1 flue gas desulfurized (FGD) gypsum (control), 896 kg ha-1 NPK fertilizer (13-13-13), 22.4 Mg ha-1 poultry litter; 22.4 Mg ha-1 swine compost, fertilizer + gypsum, litter + gypsum, and compost + gypsum at a surface lignite mine in northeast Mississippi. Experimental design was a randomized complete block with three replicates. In May 2011, treatments were incorporated to 15-cm depth, and bermudagrass (Cynodon dactylon L.) was sown using a Brillion cultipaker. In 2012 and 2013, treatments were split-applied without incorporation in May and August. Treatment effects were determined for soil chemical characteristics (0-15 and 15-30 cm depths), plant vigor, and forage dry matter (DM) yield. In the analysis across years, the year by treatment interaction was significant for DM yield (P<0.01), but ranking of treatments was similar each year and values averaged greater in litter than compost treatment (6.47 vs. 3.37 Mg ha-1). Improved DM yield was associated with greater N concentration in litter than compost (30 vs. 22 g kg-1), as well as increased P, K and Na in the surface soil in autumn 2013. Applying FGD gypsum with poultry litter reduced soil bulk density by 9% and increased cation exchange capacity by 9%, organic C by 25%, and soluble salts from 0.25 to 0.83 mmhos cm-1, as compared to litter alone. The co-application of gypsum was associated with a 21% decrease in soil organic matter (P<0.05). These data indicate applying 22.4 Mg poultry litter ha-1 yr-1 can improve soil quality and forage yield performance during reclamation of a respread area.