Comparison of carbon footprint and net ecosystem carbon budget under organic material retention combined with reduced mineral fertilizer

Table 5 Interactions of straw retention, fertilizer and study year on mean GHG, CO₂, C input, C footprint, crop biomass and NECB during the crop growing season

	GHG	CO₂	C input	C footprint	Crop biomass	NECB
Straw retention^a
−SR	9731.44	16,860.67	31,981.66	0.65	15,208.83	5.39
+ SR	15,748.89**	20,879.21	34,641.17*	0.79	20,044.44***	− 1.99
Year^b
2018	14,235.30	26,169.29	32,901.97	0.78	18,278.67	− 7.50
2019	14,253.75	13,579.86 ***	35,050.62	0.73	19,392.42	7.22***
F-values
Fertilizer * year	51.458 ***	49.338***	0.924	6.271**	1.000	6.689**

F-values are provided for interactions
GHG represents greenhouse gas; CO₂ represents carbon dioxide; C represents carbon; NECB represents net ecosystem carbon budget; − SR represents no straw (Astragalus sinicus L. and rice) retention; + SR represents straw (Astragalus sinicus L. and rice) retention
There were significant interactions (fertilizer * year) for the six variables. *(0.01 < P ≤ 0.05), **(0.001 < P ≤ 0.01), or ***(P ≤ 0.001) are used to represent significant effects among the treatments
^a,bValues were averaged across different treatments, crop, and study years

ISSN: 1750-0680