Response of Soil CO₂ Emission and Summer Maize Yield to Plant Density and Straw Mulching in the North China Plain

Table 1

Treatments with the straw mulching and plant density for summer maize.

Straw mulching (kg m^−2)	Plant density; (plants ha^−1)	Code	Planting distance (cm)
0.6	100 000	M1	17.1
	High-density
	75 000	M2	22.2
	Medium-density
	55 000	M3	31.7
	Low-density
0	100 000	N1	17.1
	High-density
	75 000	N2	22.2
	Medium-density
	55 000	N3	31.7
	Low-density