Table 3. Nitrogen uptake from ¹⁵N-labeled urea in rice plants under different biochar treatments at the harvest stage.

Temperaturea	Treatmentb		Ndff (mg pot−1)			Ndsf (mg pot−1)			REN of15N-labeled urea in rice (%)
			Mean	Std. error	SL	Mean	Std. error	SL	Mean	Std. error	SL
B400	N210	C0	316.03	13.47	a	2,054.31	53.95	a	15.80	0.67	a
		C0.7	248.08	31.50	b	1,749.50	129.86	ab	12.40	1.57	bc
		C2.1	142.13	42.86	de	1,528.75	249.03	bc	7.11	2.14	d
	N168	C0	245.59	2.39	b	1,636.33	98.99	bc	15.25	0.15	ab
		C0.7	202.32	4.08	bc	1,560.99	25.51	bc	12.57	0.25	bc
		C2.1	113.63	18.83	e	1,350.94	158.09	c	7.06	1.17	d
B700	N210	C0	306.00	25.56	a	2,046.47	81.88	a	15.30	1.28	ab
		C0.7	230.51	54.28	b	1,765.17	109.24	ab	11.53	2.71	c
		C2.1	171.26	57.10	cd	1,606.81	337.90	bc	8.56	2.86	d
	N168	C0	245.51	21.15	b	1,820.15	135.12	ab	15.25	1.31	ab
		C0.7	211.12	24.25	bc	1,584.70	143.52	bc	13.11	1.51	abc
		C2.1	109.21	21.22	e	1,378.55	216.23	c	6.78	1.32	d

Notes.

^aB400 and B700; C0, C0.7, and C2.1; and N0, N210, and N168 are defined in Table 2 footnote.

Ndff

N content in the plant or soil derived from the ¹⁵N-labeled urea

Ndfs

N content in the plant derived from the soil

REN

recovery of ¹⁵N-labeled urea in the plant tissue

SL

Significant level (different lowercase letters in a column indicate significant difference at p < 0.05)