Pesticide fate in sodded kentucky bluegrass lawns in response to irrigation

Figures & data

Figure 1.  Daily climatological data for Cornell's Turfgrass and Landscape Research Center in Ithaca, New York for the 27-month leachate study period.

Table I. Application dates and product descriptions of the fertilizer and pesticide combinations applied to the Kentucky bluegrass turfgrass plot.

Application date	Nitrogen applied	Phosphorus applied	Potassium applied	Active ingredient
	------------------------------ kg ha ^−1-------------------------------				g kg ^−1 applied
3 September 2007	36.46	1.72	8.65	Bifenthrin	0.86
24 September 2007	30.07	1.52	11.52	2,4-D; Mecoprop	12.1; 6.1
23 April 2008	41.17	1.81	4.56	Pendimethalin	12.2
26 May 2008	39.15	1.84	3.48	2,4-D; Mecoprop	12.1; 6.1
28 July 2008	36.46	1.72	8.65	Bifenthrin	0.86
3 October 2008	30.07	1.52	11.52	2,4-D; Mecoprop	12.1; 6.1
29 April 2009	41.17	1.81	4.56	Pendimethalin	12.2
26 May 2009	39.15	1.84	3.48	2,4-D; Mecoprop	12.1; 6.1
22 July 2009	36.46	1.72	8.65	Bifenthrin	0.86
16 September 2009	30.07	1.52	11.52	2,4-D; Mecoprop	12.1; 6.1
Total applied	360.23	17.04	76.59

Figure 2.  The observed differences in leachate volume (A) and runoff volume (B) from natural precipitation among irrigated and non-irrigated Kentucky bluegrass turfgrass over a 27-month period. Data break in runoff volume is due to plot renovations. During this period samples were taken and analysed for concentrations; however, no runoff volumes were recorded. Bars represent the standard error of the mean.

Figure 3.  The average soil VWC measured over several dates throughout the growing season under irrigated and non-irrigated Kentucky bluegrass turfgrass. Bars represent the standard error of the mean.

Table II. Leaching and runoff events and corresponding date ranges assigned to sample periods.

Sample period	Date range	Leachate events	Date range	Runoff events
1	8 Sept. 2007–15 Sept. 2007	1–3	8 Sept. 2007–15 Sept. 2007	1–4
2	16 Sept. 2007–27 Oct. 2007	4–9	16 Sept. 2007–27 Oct. 2007	5–13
3	28 Oct. 2007–3 Dec. 2007	10–16	28 Oct. 2007–3 Dec. 2007	14–18
4	4 Dec. 2007–11 Jan. 2008	17–23	4 Dec. 2007–11 Jan. 2008	19–21
5	12 Jan. 2008–29 Feb. 2008	24–30	12 Jan. 2008–29 Feb. 2008	22–28
6	1 Mar. 2008–4 Apr. 2008	31–37	1 Mar. 2008–4 April 2008	29–33
7	5 Apr. 2008–17 May 2008	38–39	5 Apr 2008–17 May 2008	34–35
8	18 May 2008–15 July 2008	40–41	18 May 2008–15 July 2008	36–40
9	16 July 2008–10 Aug. 2008	42–44	16 July 2008–10 Aug. 2008	41–45
10	11 Aug. 2008–15 Nov. 2008	45–47	11 Aug. 2008–15 Nov. 2008	46–50
11	16 Nov. 2008–5 Jan. 2009	48–51	16 Nov. 2008–5 Jan. 2009	51–53
12	6 Jan. 2009–30 Mar. 2009	52–55	6 Jan. 2009–30 Mar. 2009	54–57
13	31 Mar. 2009–6 May 2009	56–57	31 Mar. 2009–18 June 2009	58–62
14	7 May 2009–30 June 2009	58–61	19 June 2009–26 July 2009	63–66
15	1 July 2009–29 Aug. 2009	62–64	27 July 2009–29 Aug. 2009	67–72
16	30 Aug. 2009–15 Nov. 2009	65–68	30 Aug. 2009–15 Nov. 2009	73–75

Figure 4.  Mean concentrations of four common landscape pesticides found in leachate over time. Due to insignificant differences related to irrigation, values were averaged among treatments that received pesticides with or without irrigation. Bars represent the standard error of the mean. * pesticide application timing.

Table III. Environmental characteristics of four pesticides used in care and maintenance of turfgrass lawn type treatment.

Pesticide	Type	Water solubility	Adsorption coefficient	Aerobic soil half-life	US water standard MCL
		mg L ^−1	K oc	days	µg L ^−1
Bifenthrin	Insecticide	0.10	237,000	95	n/a
Pendimethalin	Pre-emergent herbicide	0.30	5000	40	20.0
2,4-D	Post-emergent herbicide	27,600	46.0	34.0	70.0
Mecoprop	Post-emergent herbicide	869	119	20	10.0

Figure 5.  Concentrations of four common lawn pesticides found in runoff from Kentucky bluegrass lawn types over a 27-month period. Bars represent the standard error of the mean.