The Role of Locally Derived Effective Microorganisms in Reducing Ammonia Volatilization and Enhancing Nitrogen Mineralization in Soils Fertilized with Animal Manures.

Reducing ammonia losses and improving N mineralization could help improve N use efficiency of animal manures. The objective of the study was to determine if locally derived effective microorganisms (LEMs) reduce ammonia volatilization and respiration or enhance potential nitrogen mineralization in two cropping systems: 1) Annual ryegrass (Lolium multiflorum) (Treatments- swine effluent (SE) only, SE+LEM and SE+F-LEM) and 2) Edamame (Glycine max) (Treatments- broiler litter only (BL), BL+LEM and BL+F-LEM). There were 33% and 28% reduction in nitrogen loss as ammonia from annual ryegrass plots in the first and second year of the study, respectively, from the LEM inoculated plots compared to SE treatment (P<.10). From the edamame plots, in first year and second year, the reduction in nitrogen loss as ammonia was also lower from the LEM treatments compared to BL-only, 68% and 80% (P<.10), respectively. Respiration rates were not significantly different compared to the SE- or BL-only. Nitrogen mineralization in annual ryegrass plots, when compared to baseline, decreased during the first 83 days and increased significantly afterwards in the LEM treated plots. In the edamame cropping system, nitrogen mineralization increased over time when compared to baseline (P <0.05). In the SE USA, while LEM may more consistently enhance N mineralization in a summer soybean cropping system than in a winter forage system, LEM consistently reduced ammonia volatilization in both systems.