Table 2.

Changes in root morphological features at the tillering, heading, and maturity stages as affected by ¹⁵N-labelled fertilizers with or without biochar.

Treatments	TRL	(m hill−1)	TRSA	(m2 hill−1)	TARD	(mm hill−1)	TRV	(cm3 hill−1)
Season	Early	Late	Early	Late	Early	Late	Early	Late
Tillering
T1	82.76b	88.76 d	20.29b	22.10b	0.32c	0.34 ab	25.04b	26.45c
T2	91.10 a	96.19 a	22.36 a	23.95 a	0.34 ab	0.36 a	27.57 a	28.71 a
T3	86.93 ab	89.33 cd	21.33 ab	22.24b	0.32c	0.33b	26.30 ab	26.63c
T4	90.96 a	94.02 ab	22.34 a	23.41 ab	0.33 bc	0.36 a	27.52 a	28.05 ab
T5	88.15 a	90.71 cd	21.63 ab	22.58 ab	0.34 ab	0.35 ab	26.67 a	27.04 bc
T6	91.54 a	91.89 bc	22.48 a	22.88 ab	0.35 a	0.35 ab	27.70 a	27.40 bc
Heading
T1	131.89b	137.87b	41.57c	42.55b	0.50b	0.53b	49.80b	51.88b
T2	144.83 a	154.24 a	45.91b	47.67 a	0.55 a	0.59 a	54.66 a	58.05 a
T3	135.21b	142.85b	42.07c	44.11b	0.52b	0.54b	51.02b	51.48b
T4	149.46 a	153.58 a	45.09b	47.46 a	0.57 a	0.59 a	56.40 a	57.82 a
T5	134.77b	140.33b	41.34c	43.32b	0.51b	0.53b	50.86b	52.84b
T6	149.61 a	159.90 a	47.81 a	49.44 a	0.57 a	0.61 a	56.48 a	60.20 a
Maturity
T1	117.11 bc	124.65 ab	30.90b	33.85 a	0.45b	0.48 a	42.08 a	45.03 a
T2	123.61 a	127.25 ab	32.63 a	34.55 a	0.47 a	0.48 a	44.46 a	45.95 a
T3	119.33 abc	125.38 ab	31.49 ab	34.05 a	0.45 ab	0.47 a	42.86 a	45.30 a
T4	123.52 a	129.09 a	32.59 a	35.06 a	0.47 a	0.49 a	44.41 a	46.65 a
T5	116.40c	124.12 ab	30.71b	33.71 a	0.44b	0.47 a	41.80 a	44.87 a
T6	122.17 ab	127.25 ab	32.23 ab	34.56 a	0.46 ab	0.49 a	43.84 a	45.98 a

Note: TRL—total root length, TRSA—total root surface area, TARD—total average root diameter, TRV—total root volume. (n = 3) n: number of samples at each growth stage.