. 2018 Oct 3;8:14743. doi: 10.1038/s41598-018-33040-7

Table 4.

Mean values of soil cation contents (g kg⁻¹) for different biochar application rates (B) and irrigation water salinity levels (I).

Irrigation regime	Biochar treatment	Ca	K	Mg	Na
I₀	B₁	0.07^dC	0.01^bC	0.01^cB	0.05^eA
	B₂	0.35^dB	0.09^cB	0.04^bA	0.04^dA
	B₃	0.49^eA	0.23^dA	0.05^cA	0.02^fA
I₁	B₁	0.17^cC	0.02^bC	0.02^bB	0.67^dA
	B₂	0.37^cB	0.10^cB	0.04^bA	0.23^cB
	B₃	0.51^eA	0.25^dA	0.06^cA	0.14^eC
I₂	B₁	0.19^cC	0.03^bC	0.02^bC	1.23^cA
	B₂	0.39^bB	0.12^bB	0.04^bB	0.53^cB
	B₃	0.58^dA	0.30^cA	0.07^bA	0.14^eC
Biochar		***	**	**	***
Salinity		*	ns	*	***
Interaction		**	ns	*	**

Note: In each column, different uppercase and lowercase letters indicate a significant difference among the biochar application rates and irrigation salinity levels, respectively, at P < 0.05 (Least significant difference, LSD); Analysis of variance (ANOVA): ns, not significant; *, **, and ***, denote significance at P ≤ 0.05, P ≤ 0.01, and P ≤ 0.001, respectively. B₁, B₂, and B₃ represent mixtures of soil with 0%, 2%, and 4% of biochar by mass. I₀, I₁ and I₂ represent irrigation water salinity of tap water, 1 and 3 dS m⁻¹.