Tillage and Fertilizer Management Effects on Soil-Atmospheric Exchanges of Methane and Nitrous Oxide in a Corn Production System

Table 3

Soil methane fluxes as influenced by tillage systems and ammonium nitrate (AN) and poultry litter (PL) N fertilizers using surface (SA), soil incorporation (SI), and subsurface band (BA) application methods in spring, summer, fall, and winter seasons, Hazel Green, Alabama.

	Spring	Summer	Fall	Winter	Mean flux
	CH4 flux (g ha^−1 day^−1)
Tillage systems
Conventional tillage	−2.05a^†	−1.96ab	−0.68a	3.32b	−0.34
No-tillage	−2.23a	−2.99a	−1.94a	4.24b	−0.73
Grass fallow	−1.79a	−0.26b	2.38b	−21.44a	−5.28
Fertilizer treatments
0N control	−5.97a	−1.37b	0.60b	22.15d	3.85
150 kg N ha^−1 AN-SA	−5.48a	−0.44c	−0.87b	32.16e	6.34
150 kg N ha^−1 AN-SI	3.49bc	−5.74a	−1.21b	4.65c	0.29
150 kg N ha^−1 PL-SA	4.16c	−0.30c	−1.09b	−13.12b	−2.58
150 kg N ha^−1 PL-SI	0.32b	−2.96b	1.62b	−13.95b	−3.74
150 kg N ha^−1 PL-BA	−5.25a	−5.41a	−4.77a	−18.00a	−8.36
Seasonal means	−1.74	−2.22	−0.52	−1.16

^†Means for tillage system or N fertilizer treatment within a season followed by the same letter are not significantly different at the 𝑃≤0.05 level.