title: Effect of potassium salts and distillery effluent on carbon mineralization in soil.
abstract: Distillery effluent, a rich source of potassium, is used for irrigation at many places in the world. A laboratory experiment was conducted to study the influence of potassium salts present in post-methanation distillery effluent (PME) along with two other salts, KCl and K2SO4, on mineralization of carbon in soil. PME oxidized with H2O2, raw PME, KCl and K2SO4 solutions containing K equivalent to 10%, 20%, 40% and 100% of K present in PME were added to the soil separately, maintaining four replications for each treatment and control. Addition of salts up to a certain concentration stimulated C mineralization but a decline was noticed at higher concentrations. All the levels of salts caused higher CO2 evolution than the control suggesting that the presence of K salts enhanced the microbial activity resulting in increased CO2 evolution. The influence of K2SO4 was significantly higher than KCl in stimulating C mineralization in soil. Oxidized effluent had a higher stimulating effect than inorganic salts, showing the influence of other salts accompanying K in the PME. Raw PME, which contained excess organic C, increased CO2 evolution even at the highest salt level (100% PME) signifying the effect of added C on alleviating the salt stress on microbial activity.
authors.affiliation: Division of Environmental Sciences, Indian Agricultural Research Institute, New Delhi.
authors.forename: Suresh
authors.initials: S
authors.lastname: Chandra
authors.forename: H C
authors.initials: HC
authors.lastname: Joshi
authors.forename: H
authors.initials: H
authors.lastname: Pathak
authors.forename: M C
authors.initials: MC
authors.lastname: Jain
authors.forename: N
authors.initials: N
authors.lastname: Kalra
mesh_terms: D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D007220:Industrial Waste; D008903:Minerals / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D011189:Potassium Chloride / Q000378:metabolism; D012016:Reference Values; D012492:Salts / Q000378:metabolism*; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D007220:Industrial Waste; D008903:Minerals; D012492:Salts; D012987:Soil; D012989:Soil Pollutants; D013431:Sulfates; D014867:Water; D002245:Carbon Dioxide; C031512:potassium sulfate; D011189:Potassium Chloride; D002244:Carbon; D011188:Potassium