Examining the Effect of Combined Biochar and Lime Rates on Selected Soil Physicochemical Properties of Acid Soils in Gimbi District, Western Ethiopia

Table 6

The effects of coffee husk biochar (CHB) and soil test value-based lime (STV) rates on cation exchange capacity (CEC), exchangeable acidity (EA), exchangeable aluminum (EAl), ammonium nitrogen (NH₄-N), nitrate nitrogen (NO₃-N), and total mineral nitrogen (TMN) of acidic soils.

Factor ha^−1	CEC (cmol(+)kg^−1)	EA (cmol(+)kg^−1)	EAl (cmol(+)kg^−1)	NH4-N (mg·kg^−1)	NO3-N (mg·kg^−1)	TMN (mg·kg^−1)
Farm 1
Control	5.66^g	4.64^a	3.92^a	15.55^e	21.26^a	36.81^a
100% of STV	11.82^f	1.76^e	1.07^f	17.64^d	19.03^b	36.67^a
10 ton of CHB	20.01^d	3.19^b	2.66^b	25.69^a	6.14^g	31.83^b
10 ton of CHB + 75% of STV	37.76^a	0.98^f	0.70^g	21.01^c	12.57^e	33.58^b
10 ton of CHB + 50% of STV	21.60^c	2.00^d	1.28^e	24.18^b	9.23^f	33.41^b
7.5 ton of CHB + 75% of STV	37.78^a	2.54^c	1.47^d	15.88^e	16.87^d	32.75^b
7.5 ton of CHB + 50% of STV	16.60^e	2.12^d	1.45^d	21.01^c	17.13^cd	38.14^a
5 ton of CHB + 75% of STV	24.95^b	3.05^b	2.40^c	18.52^d	18.08^bc	36.60^a
CV (%)	4.05	3.72	4.48	3.91	3.90	3.14
LSD (0.05)	0.75	0.14	0.14	1.36	1.02	1.92
Farm 2
Control	1.59^h	5.00^a	3.95^a	13.51^f	13.76^a	27.28^e
100% of STV	11.48^g	3.21^c	2.10^c	15.78^e	12.69^a	28.47^de
10 ton of CHB	19.67^e	2.79^e	2.23^b	22.78^b	6.59^e	29.37^cd
10 ton of CHB + 75% of STV	31.50^b	1.10^h	0.85^e	21.21^c	8.96^cd	30.17^bc
10 ton of CHB + 50% of STV	21.27^d	3.08^d	2.33^b	19.62^d	11.22^b	30.85^b
7.5 ton of CHB + 75% of STV	37.44^a	2.27^f	1.44^d	24.68^a	8.17^d	32.85^a
7.5 ton of CHB + 50% of STV	16.93^f	1.66^g	0.92^e	18.70^d	9.93^bc	28.63^de
5 ton of CHB + 75% of STV	24.95^c	3.38^b	2.33^b	14.15^f	11.07^bc	25.22^f
CV (%)	3.68	2.52	3.52	2.91	7.85	2.80
LSD (0.05)	1.35	0.12	0.12	0.95	1.41	1.42

ns: non-significant, : significant (), : highly significant ().