Poa pratensis or Lolium perenne for establishment and overseeding of Scandinavian football (soccer) pitches

Figures & data

Figure 1.  Map of south Norway showing experimental sites.

Table I. Thirty-year normal values (1961–90) for seasonal temperatures, length of growing season, thermal heat units, and annual precipitation at the experimental sites Landvik, Apelsvoll, and Kvithamar.

	Temperature, °C			Growing season
	Year	June–Aug.	Dec.–Feb.	Days>5 °C	Day-degree units>5 °C	Annual precip., mm
Landvik	6.9	15.4	−1.1	16 Apr. – 3 Nov.	1441	1237
Apelsvoll	3.6	14.0	−6.6	29 Apr. – 14 Oct.	1091	600
Kvithamar	5.0	13.1	−2.7	20 Apr. – 19 Oct.	1064	897

Table II. Soil characteristics of the amended topsoil at establishment in 2008: Loss on ignition, pH, and particle size analysis.

			Soil texture, per cent of weight
	Loss on ignition %	pH (H2O)	Coarse sand 0.6–2 mm	Medium sand 0.2–0.6 mm	Fine sand 0.2–0.06 mm	Silt 0.002–0.06 mm	Clay<0.002 mm
Landvik	2.0	6.7	8.8	44.1	25.2	17.7	4.2
Apelsvoll	4.0	6.3	18.0	29.9	14.6	22.5	15.0
Kvithamar	6.0	6.7	20.4	22.4	14.5	31.1	11.5

Table III. Dates for overseeding in spring (treatments 2 and 3), summer (treatments 4 and 5) and fall (treatments 6 and 7) during the experimental years. Not OS = Not overseeded.

		2009			2010			2011
	2008	Spring	Summer	Fall	Spring	Summer	Fall	Spring	Summer	Fall
Landvik	9 Oct.	24 Apr.	6 Jul.	8 Oct.	28 Apr.	25 Jun.	13 Oct.	13 Apr.	1 Jul.	14 Oct.
Apels voll	16 Oct.	14 May	13 Jul.	7 Oct.	5 May	29 Jun.	6 Oct.	4 May	1 Jul.	Not OS
Kvithamar	29 Sept.	8 May	8 Jul.	Not OS	28 Apr.	8 Jul.	3 Nov.	10 May	1 Jul.	Not OS

Table IV. Significance levels for the effect of site, year, initial turf type (TT), overseeding (OS) and their interactions on response variables as determined by PROC MIXED procedure. Symbols: ***: p≤0.001, *: 0.001<p≤0.01, *: 0.01<p≤0.05, (*): 0.05<p≤0.10, ns: p>0.10.

	Live turf cover			Tillers m^−2							Root dry weight^4
	Apr.–June	Jul.–Aug.	Sept.–Oct.	KB^1	PR^2	AB^3	Total	Shear strength	Surface hardness	Infiltration rate^4	0–5 cm depth	Under 5 cm depth
Site	*	*	*	ns	(*)	ns	(*)	**	ns	ns	*	(*)
Year	*	ns	*	ns	ns	ns	ns	ns	ns	ns	*	ns
Site×year	*	ns	***	ns	ns	ns	ns	***	ns	ns	*	(*)
Initial turf type (TT)	*	ns	ns	*	*	ns	ns	ns	ns	ns	(*)	ns
Site×TT	**	ns	ns	ns	(*)	ns	ns	ns	ns	ns	ns	ns
Year×TT	(*)	(*)	*	ns	ns	ns	ns	ns	ns	ns	ns	ns
Site×year×TT	***	ns	***	ns	ns	ns	ns	ns	ns	ns	(*)	ns
Overseeding (OS)	(*)	ns	ns	**	**	ns	ns	ns	ns	–	–	–
Site×OS	*	ns	ns	*	(*)	(*)	ns	ns	ns	–	–	–
Year×OS	*	ns	ns	*	*	ns	*	ns	ns	–	–	–
Site×year×OS	***	ns	*	*	*	ns	*	ns	ns	–	–	–
TT×OS	(*)	ns	ns	*	*	ns	(*)	ns	ns	–	–	–
Site×TT×OS	(*)	(*)	ns	(*)	ns	ns	ns	ns	ns	–	–	–
Year×TT×OS	**	ns	ns	ns	ns	ns	ns	ns	ns	–	–	–
Site×Year× TT×OS	**	ns	ns	ns	ns	ns	ns	ns	ns	–	–	–
^1Kentucky bluegrass.
^2Perennial ryegrass.
^3Annual bluegrass.
^4Infiltration rate and root dry weight were determined on unseeded control plots only.

Table V. Seasonal mean values for live turf cover (% of plot area; Kentucky bluegrass plus perennial ryegrass plus annual bluegrass) during 2008–2011 on main plots established by sodding Kentucky bluegrass (KB) and seeding perennial ryegrass (PR). Means of subplots with various overseeding treatments. Significance symbols as in Table IV.

		2008	2009			2010			2011			3- or 4-year mean
Site		Sept.–Oct.	Apr.–Jun.	Jul.–Aug.	Sept.–Oct.	Apr.–Jun.	Jul.–Aug.	Sept.–Oct.	Apr.– June	Jul.–Aug.	Sept.–Oct.	Apr.–June	Jul.–Aug.	Sept.–Oct.
Landvik	KB	99	99	100	99	96	100	86	86	99	96	94	99	95
	PR	97	95	99	97	92	100	96	61^1	100	97	83	100	97
	Sign.	(*)	*	ns	ns	ns	ns	(*)	ns	ns	ns	ns	ns	ns
Apelsvoll	KB	99	98	99	99	97	97	99	91	96	98	96	97	99
	PR	99	68	95	98	43	97	100	45	97	100	52	96	99
	Sign.	ns	*	ns	ns	**	ns	ns	*	ns	***	*	ns	ns
Kvithamar	KB	100	100	100	99	92	99	98	85	100	99	93	100	99
	PR	100	41	96	99	89	98	98	55	100	98	6	97	99
	Sign.	ns	***	(*)	ns	(*)	*	ns	*	ns	ns	*	*	ns
Mean of three sites	KB	99	99	100	99	95	99	95	87	98	98	94	99	98
	PR	99	68	97	98	75	98	98	53	99	98	65	98	98
	Sign.	(*)	*	(*)	ns	*	ns	ns	(*)	ns	ns	*	ns	ns
^1Winterkill of PR on main plot facing north only.

Figure 2.  Effect of 2–3 years overseeding of Kentucky bluegrass (KB) or perennial ryegrass (PR) at various times of year on live turf cover in spring 2011 at Kvithamar. Vertical bars indicate 1 standard error (S.E., n = 2).

Figure 3.  Effect of overseeding treatments on tiller populations of Kentucky bluegrass, perennial ryegrass and annual bluegrass on (a) main plots sodded with Kentucky bluegrass and (b) main plots seeded with perennial ryegrass at Landvik in 2010 and 2011. Vertical bars indicate 1 standard error for total tiller number (S.E., n = 2).

Figure 4.  Effect of overseeding treatments on tiller populations of Kentucky bluegrass, perennial ryegrass, and annual bluegrass on (a) main plots sodded with Kentucky bluegrass and (b) main plots seeded with perennial ryegrass at Kvithamar in 2010 and 2011. Vertical bars indicate 1 standard error for total tiller number (S.E., n = 2).

Table VI. Dry weight of living and dead roots above and below 5-cm soil depth on plots that were initially established with Kentucky bluegrass sod (KB) or perennial ryegrass seed and that were not overseeded.

	Root and thatch dry weight, g m^−2
	0–5 cm	Below 5 cm
KB	2030	112
PR	1053	143
P%	(*)	ns