Impact of the Application of Domestic Wastewater by Subsurface Drip Irrigation on the Soil Solution in Sugarcane Cultivation

Table 3

Average concentration of the water quality parameters used in irrigation during the rainy and dry periods for the first crop.

Attribute	Rainy season				Dry season
	TDS^7	CV^9 (%)	SRW^8	CV (%)	TDS	CV (%)	SRW	CV (%)
Total nitrogen (mg·L^−1)	59.23	19.67	1.06	61.45	98.05	31.66	0.68	51.61
Total phosphorus (mg·L^−1)	8.57	15.53	0.04	31.49	20.50	67.57	0.04	106.06
Potassium (mg·L^−1)	25.00	13.67	1.35	30.76	26.70	55.08	0.81	16.07
Calcium (mg·L^−1)	18.56	10.69	3.70	33.40	21.60	17.67	4.40	11.89
Magnesium (mg·L^−1)	3.30	15.74	2.48	19.68	3.80	7.44	3.18	8.21
Sulfur (mg·L^−1)	14.60	21.95	<5	n.d.	6.15	42.54	<5	n.d.
Sodium (mg·L^−1)	56.36	14.32	2.20	26.59	76.70	4.79	2.20	7.07
Boron (mg·L^−1)	0.31	44.34	<0.001	n.d.	0.20	85.99	<0.001	n.d.
Iron (mg·L^−1)	0.84	41.13	0.20	72.61	0.93	41.84	0.25	37.09
Manganese (mg·L^−1)	0.08	16.16	0.03	48.66	0.06	7.67	0.02	2.55
Zinc (mg·L^−1)	0.08	28.75	0.08	38.82	0.05	20.20	0.05	732.61
Total chlorine (mg·L^−1)	0.02	33.33	0.03	57.28	<0.01	n.d.	<0.01	n.d.
BOD^1 (mg·L^−1)	5.00	52.91	<5	n.d.	14.70	79.85	<5	n.d.
EC^2 (dS·m^−1)	0.99	15.54	0.07	14.70	1.24	8.88	0.06	5.94
SAR^3 (mmol·L^−1)	4.46	8.70	0.30	15.26	5.66	12.31	0.27	4.02
pH	7.70	2.87	7.33	5.20	7.21	12.35	7.23	1.37
FC^4 (MPN 100 ml^−1)	72167	27.97	n.d.^6	n.d.	23215380	141.16	59.00	n.d.
E. coli^5 (MPN 100 ml^−1)	66827	36.42	n.d.	n.d.	203910	124.90	66.00	n.d.

¹Biochemical oxygen demand; ²electrical conductivity; ³sodium adsorption ratio; ⁴fecal coliforms; ⁵Escherichia coli; ⁶not determined; ⁷treated domestic sewage; ⁸surface reservoir water; ⁹coefficient of variation.