To clarify the effective mechanism of applying biogas residue on the yield

the benefit and soil fertility of maize for two consecutive years

we conducted a field experiment in Hailin farm

Hailin City

Heilongjiang Province. From May 2013 to October 2014

treatments of the single biogas residues

the mixtures of biogas residues and chemical fertilizers

full dose of chemical fertilizers were applied to the test field of maize. The results showed that both applications of the biogas residues and the mixtures of biogas residues and chemical fertilizers for two consecutive years could increase the yield of maize. More specifically

the application of biogas residues at 45 000 kilogram per hectare increased the yield of maize the most significantly. However

the full dose of chemical fertilizer application at 600 kilogram per hectare slightly decreased the yield of maize. The application of biogas residue at one ton could substitute 135.25 kilogram carbamide

180.18 kilogram diammonium phosphate

and 107.09 kilogram potassium sulfate. As a result

it generated a direct economic benefit of 956.72 yuan. Application of biogas residues achieved significant more economic benefits compared with the control. Application of the mixtures of biogas residues at 7 500 kilogram per hectare and chemical fertilizers at 450 kilogram per hectare exhibited the highest economic benefits

and its average economic benefit was 18 066.2 yuan per hectare. The pH values could be increased by 0.02 to 0.28 units and the organic matter could be increased by 0.14 g/kg to 2.84 g/kg in the surface layer of soil after the single application of biogas residue

and the mixed application of biogas residues and chemical fertilizers. Nutrient contents of the surface layer of soil were also increased to some degrss. Therefore

the reasonable application of biogas residues in the practical production may replace the application of chemical fertilizers to realize the efficient and economic utilization of the biogas residue in the cold high-latitude area of the northeast China.