. 2019 May 30;14(5):e0217561. doi: 10.1371/journal.pone.0217561

Table 1. Median concentrations of anions and cations in the water under different treatments and during different cycles of crops.

Different letters in a row indicate significant differences between treatments during each cycle of crop using the Kruskal-Wallis test at p < 0.05 level. ns = not significant.

Parameters (mg L^-1)	Catalogna			Lettuce			Swiss Chard
Parameters (mg L^-1)	HP	APL	APH	HP	APL	APH	HP	APL	APH
NH₄⁺	0.53^b	0.57^b	0.87^a	0.53^c	0.91^b	1.63^a	0.50^c	0.94^b	1.18^a
NO₂^-	17.77^ns	17.02^ns	14.20^ns	0.03^b	0.05^b	0.19^a	0.06^b	0.09^b	0.17^a
NO₃^-	705.0^a	34.3^b	3.1^c	575.6^a	113.4^b	4.8^c	406.2^a	139.1^b	6.5^c
PO₄^3-	8.2^b	62.9^a	64.7^a	17.6^b	99.4^a	95.3^a	5.0^b	53.9^a	62.3^a
K⁺	155.3^ns	156.7^ns	160.2^ns	108.4^b	121.0^b	142.6^a	64.7^c	82.9^b	125.5^a
Mg²⁺	72.9^b	80.2^a	81.1^a	80.0^c	83.5^b	87.9^a	82.2^c	88.3^b	93.4^a
Ca²⁺	188.5^a	88.2^b	90.5^b	164.5^a	102.1^b	92.1^c	172.2^a	115.2^b	96.7^c
Na⁺	11.6^b	11.6^b	12.7^a	15.0^b	15.5^b	17.1^a	14.5^b	14.2^b	17.6^a
Cl^-	15.1^b	16.1^ab	18.6^a	18.7^c	22.9^b	27.2^a	19.3^c	26.1^b	30.5^a
SO₄^2-	400.5^b	410.3^ab	423.8^a	413.0^c	434.3^b	466.6^a	426.6^b	465.1^a	483.5^a