Salinity and sodicity hazard characterization in major irrigated areas and irrigation water sources, Northern Ethiopia

Figures & data

Table 1. Chemical characteristics of irrigation water from groundwater source

Water source	pH	ECiw (µS/cm)	Soluble cations (meq/l)				SAR	Soluble anions (meq/l)				RSC
			Ca2+	Mg2+	Na^+	K+		SO4^2-	Cl^−	HCO3^−	CO3^2-
Shwarobit river	8.0	341.7	7.98	4.68	3.92	0.45	1.55	2.23	7.69	4.38	1.4	−0.59
Groundwater	8.9	1452.9	22.12	12.21	11.27	0.73	1.55	2.37	21.11	16.67	3.80	−13.86

ECiw = Electrical conductivities of irrigation water; SAR = Sodium adsorption ratio; RSC = Residual sodium carbonate.

Table 5. Physical & Exchangeable chemical properties of the soils irrigated by a combination of shwarobit River and groundwater sources

Depth (cm)	Texture	ρb	TP (%)	Exchangeable bases (meq/100 g)				TEB	CEC (meq/100 g)	PBS (%)	ESP (%)
				Ca	Mg	Na	K
0–30	Clay	1.30	50.94	26.56	13.12	6.80	2.36	48.84	54.58	89.48	12.46
30–60	Clay	1.32	50.19	32.15	16.12	9.85	2.82	60.94	62.84	96.98	15.67
60–90	Clay	1.35	49.91	28.67	18.50	11.88	2.92	61.97	63.53	97.54	18.70
90–120	Clay	1.39	47.55	30.48	18.89	14.01	3.52	66.90	66.95	99.92	20.93
120–150^+	Clay	1.48	44.15	31.68	16.78	12.15	3.94	64.55	66.15	97.58	18.37

TEB = Total exchangeable bases; CEC = Cation exchange capacity; PBS = Percent base saturation; ESP = Exchangeable sodium percentage.

Table 2. Salinity, sodicity and RSC hazard classes of the investigated irrigation water sources

Water source	Salinity (EC) hazard		Sodicity (SAR) hazard		Residual Na2CO3 hazard
	Class	Hazard	Class	Hazard	Class	Hazard
Shwarobit river	C2	Medium	S1	Low	1	Safe
Groundwater	C3	High	S2	Medium	1	Safe

EC = Electrical conductivity; SAR = Sodium adsorption ratio; RSC = Residual sodium carbonate.

Table 3. Physical &Exchangeable chemical properties of the soils irrigated by Shwarobit River

Depth (cm)	Texture	ρb	TP (%)	Exchangeable bases (meq/100 g)				TEB	CEC (meq/100 g)	PBS (%)	ESP (%)
				Ca	Mg	Na	K
0–30	Clay	1.38	48	29.12	8.15	5.13	2.99	45.39	55.12	82.34	9.30
30–60	Clay	1.41	47	30.33	10.42	6.62	1.68	49.05	59.21	82.84	11.18
60–90	Clay	1.47	45	35.11	13.45	6.51	1.72	56.79	61.42	92.46	10.59
90–120	Clay	1.49	44	34.25	14.01	8.41	1.52	58.19	59.19	98.31	14.42
120–150^+	Clay	1.52	43	35.21	16.15	9.33	1.27	61.96	62.27	99.50	14.98

TP = Total porosity. ρb = Bulk Density TEB = Total exchangeable bases; CEC = Cation exchange capacity; PBS = Percent base saturation; ESP = Exchangeable sodium percentage.

Table 4. Some soluble chemical properties of the soils irrigated by Shwarobit River

Depth (cm)	pH (H2O)	ECe (dS/m)	Soluble cations (meq/l)				SAR	Soluble anions (meq/l)
			Ca^2+	Mg^2+	Na^+	K^+		SO4^2-	Cl^−	HCO3^−	CO3^2-
0–30	8.6	5.11	9. 41	4.13	9. 54	2.79	3.67	8.72	13.11	2.79	Nil
30–60	8.8	6.23	10.91	5.91	11.51	2.84	3.97	12.42	16.36	2.92	Nil
60–90	8.8	6.37	12.71	4.51	16.21	2.14	5.53	11.29	17.72	1.89	Nil
90–120	8.9	6.21	10.33	5.14	21.22	1.89	7.63	11.48	12.83	1.48	Nil
120–150^+	9.3	6.45	13.41	6.12	30.25	2.21	9.95	14.41	28.25	1.96	Nil

ECe = Electrical conductivity of saturated paste extract; SAR = Sodium adsorption ratio

Table 6. Some soluble chemical properties of the soils irrigated by a combination of Shwarobit River and groundwater sources

Depth (cm)	pH (H2O)	ECe (dS/m)	Soluble cations (meq/l)				SAR	Soluble anions (meq/l)
			Ca^2+	Mg^2+	Na^+	K^+		SO4^2-	Cl^−	HCO3^−	CO3^2-
0–30	8.5	5.79	30.74	5.38	31.29	3.29	7.36	29.86	34.12	1.59	Nil
30–60	8.8	6.21	32.82	6.84	32.91	3.16	7.40	33.21	36.98	1.24	Nil
60–90	8.9	6.41	34.79	5.87	36.49	2.98	9.49	32.29	38.95	1.13	Nil
90–120	9.1	5.88	32.21	6.41	42.79	2.12	9.74	33.12	33.97	1.78	Nil
120–150^+	9.3	6.56	33.89	7.27	51.86	2.86	11.42	35.26	50.21	1.93	Nil

ECe = Electrical conductivity of saturated paste extract; SAR = Sodium adsorption ratio