Table 1.

Effects of different treatments on morphological indicators of maize in different soil layers.

Year	Morphological characteristics	0–15 cm		15–30 cm		30–45 cm		45–60 cm
		CK	AI	CK	AI	CK	AI	CK	AI
2020	Root length (cm)	708.40	833.76	233.71	272.71	212.52	251.81	141.68	165.86
	Root surface area (cm2)	225.02	294.13*	344.62	448.45*	87.16	114.08*	66.91	85.10*
	Root volume (cm3)	4.68	5.81	10.31	13.16*	1.38	1.63	0.65	1.11**
2021	Root length (cm)	694.50	966.45*	236.13	315.20*	216.31	277.41	143.80	194.96*
	Root surface area (cm2)	223.55	318.04*	344.49	490.52*	87.74	118.93*	63.22	85.11*
	Root volume (cm3)	5.18	7.53**	10.42	14.04*	1.30	1.52	0.42	0.67*
2022	Root length (cm)	778.52	1,050.31*	256.90	379.05*	233.75	320.34*	155.70	250.02**
	Root surface area (cm2)	253.65	406.47**	395.47	610.17**	100.73	160.28**	73.25	131.20**
	Root volume (cm3)	4.92	6.56	10.64	14.28*	1.31	1.82*	1.09	1.24
2023	Root length (cm)	806.85	1,239.31*	249.81	384.19**	231.09	320.91*	162.79	286.31*
	Root surface area (cm2)	272.87	454.66**	424.19	701.23**	108.04	164.99**	87.95	128.63*
	Root volume (cm3)	4.70	6.12*	9.46	12.50*	1.40	1.80*	1.51	1.85*

*Indicates a significant difference between group comparisons (p < 0.05), **indicates a highly significant difference between group comparisons (p < 0.01).