Location: Genetics and Sustainable Agriculture ResearchTitle: Animal waste and FGD gypsum effects on bermudagrass and soil leachate nutrient contents
|LANG, DAVID - Mississippi State University|
|MCGREW, N - North America Coal Cooperation|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/3/2015
Publication Date: 6/7/2015
Citation: Read, J.J., Adeli, A., Lang, D.J., Mcgrew, N.R. 2015. Animal waste and FGD gypsum effects on bermudagrass and soil leachate nutrient contents. American Society of Mining and Reclamation, 32nd Annual Conference (Poster paper), 7-11 June 2015, Lexington, KY. CD-ROM.
Technical Abstract: In previous experiments on newly relcaimed coal mine soils in northeastern Mississippi, applying poultry litter at 22.4 Mg ha-1 yr-1 enhanced bermudagrass (Cynodon dactylon L.) biomass and selected soil quality parameters. Additionally, co-application of 11.2 Mg ha-1 FGD gypsum and litter reduced soil bulk density by 5% and increased cation exchange capacity by 9%, as compared to litter only. Apparently, organic (manure) and inorganic (gypsum) amendments in these replicated plots (3.7 x 12.2 m) improved soil physical and chemical properties which may in turn influence nutrient cycling and leaching. Objective of this study was to determine the fate of applied N and P in forage biomass (kg ha-1) and in soil leachate. Four treatments of (i) 896 kg ha-1 NPK fertilizer (13-13-13), (ii) 22.4 Mg ha-1 litter, (iii) 22.4 Mg ha-1 swine compost, and (iv) litter + FGD gypsum were split-applied without incorporation in May and August 2013 and 2014. Samples of leachate water were collected periodically at 60-cm depth using suction lysimeters, and contents of inorganic N (nitrate + ammonium) and total P expressed as the product of volume and nutrient concentration (mg L-1). Based on a 1 m2 area of influence, <0.01% of the inorganic N and <0.002% of the total P applied each year in animal wastes was captured in leachate water. Soil test P and leachate P load were greatest with poultry litter and least with fertilizer. Cumulative P load in litter treatment was reduced 72% through the co-application of FGD gypsum. Poultry litter generally increased N load, probably owing to high inorganic N concentration of this waste material (18 g kg-1), as compared with swine compost (3 g kg-1). Cumulative N load did not differ between poultry litter and litter + gypsum treatment. For litter-amended plots, greater forage biomass in 2013 than 2014 (8.8 vs. 7.9 Mg ha-1) was associated with high average P load of approximately 683 x 10-6 g, as compared with 445 x 10-6 g in 2014. Similarly, average N load was 783 and 359 x 10-6 g in 2013 and 2104, respectively. This study addressed factors contributing to variability in N and P leaching.