Table 2 Annual average total CH₄ and N₂O emissions, SGWP, NEEP-sacled SGWP, and the emission factors (EF) of CH₄ and N₂O from the SP, RM and RS fields.

Treatment	CH₄ emission	N₂O emission	SGWP^a	NEEP-scaled SGWP^b	Shrimp yield	Grain yield	NEEP	EF of CH₄^c	EF of N₂O^d
Treatment	kg/ha	kg/ha	t CO_{2 − eq}/(ha·yr)	kg CO_{2 − eq} per $/(ha·yr)	t/ha	t/ha	×10³$/ha	EF_−C (%)	EF_−N(%)
SP	103 ± 10^a	4.22 ± 0.53^a	5.78 ± 0.22^a	1.05 ± 0.11^a	4.0 ± 0.25^b	/	5.51 ± 35^c	5.65 ± 0.46^a	0.47 ± 0.031^a
RM	490 ± 46^c	7.39 ± 0.73^b	24.1 ± 1.28^c	125 ± 11^c	/	6.9 ± 0.2	0.19 ± 0.02^a	21.1 ± 1.8^c	2.06 ± 0.16^c
RS	189 ± 18^b	4.32 ± 0.42^a	9.66 ± 0.45^b	4.76 ± 0.25^b	1.1 ± 0.1^a	6.1 ± 0.2	2.03 ± 0.14^b	7.81 ± 0.65^b	0.90 ± 0.073^b

Values are means of replicates ± standard deviation (mean ± SD). Different superscripts in the same column indicate significant difference (P < 0.05). “/” means no data.
^aThe latest IPCC SGWP factors (mass basis) used here for CH₄ and N₂O are 45 and 270 over the time horizon of 100 years, respectively (IPCC, 2013)³⁷.
^bThe NEEP-scaled SGWP refers to kg CO_{2 − eq} per the net ecosystem economic profits (NEEP) of SP, RM and RS fields.
^cThe direct emission factor of C for CH₄(EF_{− C}) was calculated by dividing the total CH₄ emission by total input C (SP 1826 kg/ha, RM 2325 kg/ha, and RS 24115 kg/ha, respectively).
^dThe direct emission factor of N for N₂O (EF_{− N}) was calculated by dividing the total N₂O-N emission by total input N (SP 889.56 kg/ha, RM 359.24, and RS 478.36, respectively.
^eDifferent letters in a single column indicate significant difference between fields at P < 0.05.

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