Sulfentrazone mobility in columns filled with ultisol and oxisol horizons

Abstract

Sulfentrazone is an important herbicide in the management of weeds that are difficult to control in crops such as soybeans and sugarcane. With the increase in cases of herbicide-resistant weeds, the trend is that pre-emergence application of sulfentrazone will be more widespread in the coming years. This may result in a greater likelihood of contamination of subsurface waters. Thus, it is essential to understand sulfentrazone leaching, considering the chemical, physical and structural heterogeneity that exists along the soil profile to estimate the potential for contamination of this herbicide in the soil more accurately. Therefore, the objective of this study was to evaluate sulfentrazone leaching in horizons A, B, and C as well as their mixtures, AB and ABC, in an Ultisol and an Oxisol. The test was performed using 50-cm columns containing the soil horizons subjected to 60 mm of precipitation. Sulfentrazone leaching presented the following increasing order in Ultisol: A < AB < ABC < B < C, and in the Oxisol, it was A < ABC < AB < C < B. Therefore, sulfentrazone leaching occurs heterogeneously in Ultisol and Oxisol profiles and the influence of the horizons on sulfentrazone leaching is different between soils since they have different natures from their formation. Furthermore, sulfentrazone leaching is facilitated in the deeper horizons of both soils, which increases the potential for groundwater contamination when this herbicide exceeds the first 10 cm of the soil surface.

Appendix

Appendix 1

Chemical structure of sulfentrazone in two (A) and three (B) dimensions. Source: Chemicalize.

Appendix 2

Percentage of similarity between the variables: sorghum intoxication at 7 (INT 7) and 14 (INT 14) days after emergence, shoot (SDM), root (RDM) and total (TDM) dry matter in Ultisol horizons.

Appendix 3

Percentage of similarity between the variables: sorghum intoxication at 7 (INT 7) and 14 (INT 14) days after emergence, shoot (SDM), root (RDM) and total (TDM) dry matter in Oxisol horizons.

Appendix 4

Photograph of sorghum plants 14 days after emergence treated with sulfentrazone (1000 g ha⁻¹) in horizons A, B, C, AB and ABC of a Ultisol.

Appendix 5

Photograph of sorghum plants 14 days after emergence, treated with sulfentrazone (1000 g ha⁻¹) in horizons A, B, C, AB and ABC of an Oxisol.

Appendix 6

Chromatograms extracted from the matrix of horizons A, B, C, AB and ABC of a Ultisol, with (black line) and without (red line) the presence of sulfentrazone at a concentration of 1 mg L⁻¹, at a retention time (t_R) of 8.4 min.

Appendix 7

Chromatograms extracted from the matrix of horizons A, B, C, AB and ABC of an Oxisol, with (black line) and without (red line) the presence of sulfentrazone at a concentration of 1 mg L⁻¹, at a retention time (t_R) of 8.4 min.

Appendix 8

Analytical curves with matrix overlapping of horizons A, B, C, AB and ABC of a Ultisol.

Appendix 9

Analytical curves with matrix overlapping of horizons A, B, C, AB and ABC of an Oxisol.

Appendix 10

Dispersion of the regression residuals of the analytical response as a function of the concentration of sulfentrazone applied to horizons A, B, C, AB and ABC of a Ultisol.

Appendix 11

Dispersion of the regression residuals of the analytical response as a function of the concentration of sulfentrazone applied to horizons A, B, C, AB and ABC of an Oxisol.

Appendix 12

Detection (DL) and quantification limits (QL) of the sulfentrazone extraction method in horizons A, B, C, AB and ABC of a Ultisol and an Oxisol.

Soil	Horizons	DL (mg kg−1)	QL (mg kg−1)
Ultisol	A	0.0036	0.0118
	B	0.0028	0.0093
	C	0.0029	0.0095
	AB	0.0146	0.0482
	ABC	0.0006	0.0020
Oxisol	A	0.0066	0.0219
	B	0.0184	0.0607
	C	0.0252	0.0830
	AB	0.0225	0.0743
	ABC	0.0210	0.0692

Appendix 13

Recovery percentage (%R) obtained by the analysis of extracts from horizons A, B, C, AB and ABC of a Ultisol and an Oxisol, fortified at three concentration levels of sulfentrazone.

Theoretical concentration (mg kg−1)	Real concentration (Average) (mg kg−1)	% R
	Ultisol—horizon A
0.2	0.14	71.09
0.6	0.68	113.02
1.0	1.01	101.44
	Ultisol—horizon B
0.2	0.14	71.02
0.6	0.65	108.03
1.0	0.93	92.87
	Ultisol—horizon C
0.2	0.14	71.12
0.6	0.66	109.61
1.0	0.95	94.76
	Ultisol—horizon AB
0.2	0.16	81.39
0.6	0.62	103.65
1.0	0.90	90.21
	Ultisol—horizon ABC
0.2	0.15	75.86
0.6	0.66	109.76
1.0	0.94	94.31
	Oxisol—horizon A
0.2	0.18	91.31
0.6	0.61	102.31
1.0	0.98	98.08
	Oxisol—horizon B
0.2	0.21	105.60
0.6	0.69	114.37
1.0	0.99	99.32
	Oxisol—horizon C
0.2	0.21	102.97
0.6	0.60	99.48
1.0	0.94	93.70
	Oxisol—horizon AB
0.2	0.22	108.14
0.6	0.63	105.06
1.0	0.86	85.79
	Oxisol—horizon ABC
0.2	0.19	95.24
0.6	0.56	94.09
1.0	0.86	85.80

Appendix 14

Average concentration and variation coefficient (VC) obtained from extraction in horizons A, B, C, AB and ABC of a Ultisol and an Oxisol, fortified at three concentration levels of sulfentrazone in three replicates.

Theoretical concentration (mg kg−1)	Real concentration (Average) (mg kg−1)	VC (%)
	Ultisol—horizon A
0.2	0.13	9.09
0.6	0.68	5.88
1.0	1.01	0.67
	Ultisol—horizon B
0.2	0.14	15.04
0.6	0.65	8.59
1.0	0.93	5.50
	Ultisol—horizon C
0.2	0.14	9.49
0.6	0.66	2.49
1.0	0.95	3.11
	Ultisol—horizon AB
0.2	0.16	13.50
0.6	0.62	8.05
1.0	0.90	9.61
	Ultisol—horizon ABC
0.2	0.15	5.88
0.6	0.66	7.06
1.0	0.94	2.95
	Oxisol—horizon A
0.2	0.18	2.90
0.6	0.61	5.60
1.0	0.98	6.40
	Oxisol—horizon B
0.2	0.21	3.86
0.6	0.69	6.29
1.0	0.99	11.31
	Oxisol—horizon C
0.2	0.21	4.27
0.6	0.60	6.06
1.0	0.94	14.32
	Oxisol—horizon AB
0.2	0.22	5.89
0.6	0.63	5.63
1.0	0.86	2.47
	Oxisol—horizon ABC
0.2	0.19	3.68
0.6	0.56	1.97
1.0	0.86	2.20

Appendix 15

Average concentration and variation coefficient (VC) obtained from extraction in horizons A, B, C, AB and ABC of a Ultisol and an Oxisol, fortified at three concentration levels of sulfentrazone in three replicates, for the different days of analysis.

Theoretical concentration (mg kg−1)	Real concentration (mg kg−1)			Average (mg kg−1)	VC (%)
	Day 1	Day 2	Day 3
	Ultisol—horizon A
0.2	0.14	0.16	0.16	0.15	16.47
0.6	0.68	0.68	0.68	0.68	4.55
1.0	1.01	1.26	1.27	1.18	13.85
	Ultisol—horizon B
0.2	0.14	0.18	0.19	0.17	19.24
0.6	0.65	0.66	0.66	0.66	7.88
1.0	0.93	1.07	1.07	1.02	8.86
	Ultisol—horizon C
0.2	0.16	0.20	0.21	0.19	13.97
0.6	0.66	0.66	0.67	0.66	3.38
1.0	0.95	1.06	1.08	1.03	6.62
	Ultisol—horizon AB
0.2	0.16	0.19	0.20	0.18	13.19
0.6	0.62	0.63	0.64	0.63	6.52
1.0	0.90	1.03	1.04	0.99	8.99
	Ultisol—horizon ABC
0.2	0.17	0.21	0.19	0.19	17.25
0.6	0.66	0.66	0.67	0.66	5.25
1.0	0.94	1.11	1.06	1.04	7.67
	Oxisol—horizon A
0.2	0.18	0.24	0.21	0.21	16.19
0.6	0.61	0.64	0.64	0.63	5.96
1.0	0.98	1.12	1.09	1.06	9.20
	Oxisol—horizon B
0.2	0.21	0.24	0.25	0.23	8.37
0.6	0.69	0.69	0.71	0.70	6.02
1.0	0.99	1.13	1.15	1.09	11.29
	Oxisol—horizon C
0.2	0.21	0.24	0.26	0.23	11.07
0.6	0.60	0.60	0.61	0.60	5.48
1.0	0.94	1.05	1.07	1.02	14.15
	Oxisol—horizon AB
0.2	0.22	0.26	0.27	0.25	16.02
0.6	0.63	0.64	0.64	0.64	4.65
1.0	0.86	0.98	0.98	0.94	6.88
	Oxisol—horizon ABC
0.2	0.19	0.21	0.21	0.20	6.54
0.6	0.56	0.57	0.58	0.57	2.55
1.0	0.86	0.83	0.87	0.85	2.20