Sludge derived from cow manure anaerobically digested to produce biogas (methane; CH4) was applied to maize (Zea mays L.) cultivated in a nutrient-low, alkaline, saline soil with electrolytic conductivity 9.4 dS m(-1) and pH 9.3. Carbon dioxide (CO2) emission increased 3.1 times when sludge was applied to soil, 1.6 times when cultivated with maize and 3.5 times in sludge-amended maize cultivated soil compared to the unamended uncultivated soil (1.51 mg C kg(-1) soil day(-1)). Nitrous oxide (N2O) emission from unamended soil was -0.0004 mu g nitrogen (N) kg(-1) soil day(-1) and similar from soil cultivated with maize (0.27 mu g N kg(-1) soil day(-1)). Application of sludge increased the N2O emission to 4.59 mu g N kg(-1) soil day(-1), but cultivating this soil reduced it to 2.42 mu g N kg(-1) soil day(-1). It was found that application of anaerobic digested cow manure stimulated maize development in an alkaline saline soil and increased emissions of CO2 and N2O.
