Nitrate Sorption in an Agricultural Soil Profile

Table 1

Physiochemical properties of iso-humic soil from Chott Mariam.

	Depths
	0–25 cm	25–60 cm	60–90 cm	90–120 cm
pH	8.12	8.41	8.56	8.54
CEC (meq/100 g of soil)	19.72	22.04	23.45	23.45
OM (%)	0.7	0.9	1.1	1.3
Total C (mg kg^−1)	10988	8255	20988	27093
Total N (mg kg^−1)	900	540	510	260
N-NO3 (mg kg^−1)	86.47	36.15	169.25	38.21
N-NH4 (mg kg^−1)	6.68	3.29	3.57	3.39
Exchangeable P (mg kg^−1)	93.68	20.9	4.12	4.99
Exchangeable Na (mg kg^−1)	57.5	232.3	533.6	124.2
Exchangeable Al (mg kg^−1)	76.68	87.23	72.79	51.55
Exchangeable Ca (mg kg^−1)	5450.38	5508.61	5874.56	17306.04
Exchangeable K (mg kg^−1)	491.23	299.77	135.49	106.61
Exchangeable Mg (mg kg^−1)	410.16	433.23	356.83	461.68
Exchangeable Mn (mg kg^−1)	59.16	52.54	22.95	4.22
Exchangeable Fe (mg kg^−1)	33.57	24.62	9.01	3.38
Clay (%)	12.8	24.4	30.5	25.8
Silt (%)	38	15.2	10	15.2
Sand (%)	49.2	60.4	59.5	59.1
Texture	Sandy loam	Sandy loam	Clay	Clay loam