Integration of tillage and planting density improves crop production and carbon mitigation of maize/pea intercropping in the oasis irrigation area of northwestern China

•The maize/pea intercropping improved by integrated with no-tillage and maize plant density.•The integrated system increased the crop production by 14.5 % compared to conventional practice.•The integrated system was beneficial in the carbon mitigation.•High carbon emission efficiency is attributed to reduce carbon emission of maize pea co-growth stage.