. 2020 Oct 13;6(10):e05255. doi: 10.1016/j.heliyon.2020.e05255

Table 5.

Phytochemicals, antioxidant activity of cowpea roots and leaves following application of biochar and inorganic phosphorus fertilizer (TSP).

Treatment	Sample	Phenols (mg GAE g⁻¹)	Flavonoids (mg QE g⁻¹)	Antioxidant activity (mg AAE g⁻¹)	Alkaloids (% w/w)	Tannin (mg TAE g⁻¹)	Saponin (mg DE g⁻¹)
Control	Leaves	1.39 ± .03^c	0.37 ± 0.02^de	0.07 ± 0.01^b	0.65 ± 0.04^c	0.11 ± .02^b	1.02 ± .02^de
	Roots	0.89 ± .04^a	0.13 ± 0.02^a	0.05 ± 0.01^a	0.31 ± 0.02^a	0.07 ± 0.01^a	0.64 ± .04^a
BC1.5	Leaves	2.32 ± 0.03^g	0.74 ± 0.03^f	0.11 ± 0.01^de	0.90 ± 0.04^d	0.15 ± .02^cd	1.10 ± .02^f
	Roots	1.10 ± 0.02^b	0.20 ± 0.02^b	0.08 ± 0.01^bc	0.46 ± 0.02^b	0.10 ± .01^b	0.83 ± .02^b
BC2.5	Leaves	4.16 ± 0.04^h	0.78 ± 0.03^g	0.14 ± 0.01^f	1.05 ± 0.04^e	0.17 ± .02^d	1.14 ± .01^f
	Roots	1.81 ± 0.02^d	0.27 ± 0.02^c	0.09 ± 0.02^cd	0.50 ± 0.01^b	0.10 ± 0.02^b	0.91 ± 0.04^c
BC1.5 + P	Leaves	4.29 ± 0.04ⁱ	1.04 ± 0.02^h	0.16 ± 0.01^g	1.31 ± 0.05^f	0.23 ± 0.01^e	1.29 ± 0.10^g
	Roots	1.92 ± 0.04^e	0.34 ± 0.02^d	0.12 ± 0.02^e	0.58 ± 0.02^c	0.1433 ± 0.01^c	1.013 ± 0.02^d
BC2.5 + P	Leaves	5.02 ± 0.09^j	1.11 ± 0.03ⁱ	0.19 ± 0.01^h	1.86 ± 0.12^g	0.28 ± 0.02^f	1.35 ± 0.03^ef
	Roots	2.02 ± 0.02^f	0.39 ± 0.02^e	0.12 ± 0.01^e	0.61 ± 0.03^c	0.15 ± 0.01^cd	1.08 ± 0.02^g
% CV		1.6	3.7	9.4	5.8	10	3.6

BC1.5 = biochar at 1.5 t ha⁻¹, BC2.5 = biochar at 2.5 t ha⁻¹, GAE = Gallic acid equivalent, QE = Quercetin equivalent, DE = Diosgenin equivalent, w = Weight. AA = Antioxidant activity, TAE = Tannic acid equivalent. Each value is presented as mean ± standard deviation. Means in the same column lettered with same alphabets superscript are not significantly different at p < 0.05 using Fisher's protected LSD test.