Nitrification-inhibiting Effect of Dicyandiamide and Sulfur on Apple Orchard Soil Using Barometric Process Separation Screening, denitrification characteristics, and anaerobic ammonium oxidation ability of denitrifying bacterium aHD7. Dynamic of denitrification rate and N2O flux in maize field Nitrification-inhibiting Effect of Dicyandiamide and Sulfur on Apple Orchard Soil Using Barometric Process Separation THE ECOLOGICAL DISTRIBUTIONS OF BACTERIA AND ALGAE IN THE STIMULATING WETLAND SYSTEM