1998 Iowa Turfgrass Research Report

1998 Iowa Turfgrass Research Report

Effects of Soil Amendments on the Chemical and Physical Soil Parameters of a Sand-based Golf Green

Young K. Joo, Nick E. Christians, Deying Li, and David D. Minner

The objective of this study is to investigate the effects of inorganic soil amendment materials Bio-ceramic, Profile, Axis, and Bio-Flex-A-Clay on the chemical and physical soil parameters of a sand-based golf green. Bio-ceramic is a ceramic material from Korea. Axis is a diatomaceous earth and Profile is a porous ceramic clay material. Bio-Flex-A-Clay is a polymer coated sand from a product of True Pitch, Inc. of Altoona, Iowa. The Bio-Flex-A-Clay is the same product with a kelp material incorporated on the Flex-A-Clay. A USGA type sand-based green was constructed in the summer of 1996. The green consisted of a 12-inch sand rootzone placed over a 4-inch gravel blanket. No intermediate "choaker" layer was used between the sand and the gravel blanket. The sand and pea gravel materials used in the plot met the particle size specifications of a USGA green. A network of 4-inch drain lines were trenched into the subsoil below the gravel blanket. No organic or inorganic amendments were used in green construction since they were added at a later date as treatments. The study area consisted of five treatments (Table 1) replicated six times. The 15 plots each measured 6 x 9 ft. The sand from each plot was removed to a 6-inch depth. The sand was combined with 5% volume/volume Dakota peat and 10% of each of the amendments as outlined in Table 1. The mixture was then replaced on the plot area and allowed to settle. The area was seeded with 1 lb. 'Crenshaw' creeping bentgrass/1000 ft² in September of 1996. A 10-20-10 fertilizer was applied to supply 1 lb. N/1000 ft² as a starter fertilizer.

Table 1. The five treatments established in the sand green.

	Treatment	Sand %	Amendment %	Dakota Peat %
1	Control	95	0	5
2	Bio-ceramic	85	10	5
3	Profile	85	10	5
4	Axis	85	10	5
5	Bio-Flex-A-Clay	85	10	5

The grass was severely damaged by winter kill and was reseeded with 1.5 lb. Crenshaw/1000 ft² on May 13, 1997. Starter fertilizer was reapplied at the same rate as that used in the fall.

The grass became fully established during the 1997 season. In November of 1997, soil samples were collected for chemical testing. The samples were submitted to Harris Laboratory of Lincoln, NE and a full set of chemical evaluations were conducted. Undisturbed-intact soil columns were collected in November 1997 to develop a water release curve and test other soil physical parameters. These tests included saturated water conductivity, water retention at 40 cm, and soil bulk density. Each treatment was also sampled immediately after plot construction to develop soil physical measurements on recompacted samples. The samples were recompacted according to United States Golf Association specifications and each test was repeated.

Establishment data for May, July, and August demonstrated that the Bio-Flex-A-Clay had a very positive effect on the growth of the creeping bentgrass during grow-in (Table 2). This material contains kelp, which evidently affected establishment.

In chemical analysis, Profile was most effective in increasing cation exchange of the media (Table 3). Profile also doubled the amount of exchangeable potassium (K) and increased magnesium (Mg) by nearly 50%.

Saturated water conductivity was reduced by Bio-Flex-A-Clay (Table 4). Profile and Axis increased water retention and decreased bulk density as compared to the control.

Water release curves were very similar for the control, Bio-ceramic, and Bio-Flex-A-Clay. The Profile and Axis both resulted in higher water retention at each of the pressure treatments from 0 to 2 bars (Figure 1).

We would like to acknowledge the National Natural Science Foundation of China for partial support of this research.

Table 2. Establishment data (% cover) in May, July, and September of 1997.

	Treatment	May	July	August	October
1	Control	10	60	77	100
2	Bio-ceramic	13	60	80	100
3	Profile	10	57	80	100
4	Axis	10	47	67	100
5	Bio-Flex-A-Clay	80	100	100	100
	LSD0.05	5	15	13	-

Table 3. Soil test results for the inorganic soil modification study.

Treatments	CEC	PH	SS	Na	OM	NIT	P	K	Mg	Ca
Control	8.8	8.3	1	16	0.4	1	7.7	25	103	1551
Bio-ceramic	9.2	8.3	1	17	0.4	1	6.3	27	114	1625
Profile	9.5	8.2	1	20	0.4	1	7.7	51	145	1604
Axis	8.8	8.3	1	17	0.4	1	8.7	25	105	1548
Bio-Flex-A-Clay	8.0	8.3	1	14	0.5	1	7.3	24	1038	1394
LSD0.05	0.4	NS1	NS	NS	NS	NS	NS	8	14	49
	S	Zn	Mn	Cu	Fe	B	AK	AMg	ACa	ANa
Control	1.7	0.9	3.1	0.5	11.9	0.3	0.7	9.8	88.7	0.8
Bio-ceramic	1.0	1.4	3.6	2.1	15.5	0.3	0.8	10.3	88.1	0.8
Profile	1.3	0.9	2.9	0.9	17.3	0.3	1.4	12.8	84.9	0.9
Axis	1.7	0.7	3.3	0.4	15.3	0.3	0.7	10.0	88.4	0.9
Bio-Flex-A-Clay	2.7	1.2	3.3	0.9	11.9	0.3	0.8	11.3	87.2	0.8
LSD0.05	NS	NS	NS	NS	NS	NS	0.2	1.2	1.3	NS

¹NS = Not significant at 0.05 level

CEC = Cation Exchange Capacity (meg/100g)

SS = Soluble salts (mmhos/cm)

Na = Sodium (ppm)

OM = Organic matter (%)

NIT = Nitrate N (ppm)

AK = Actual potassium (% base saturation)

AMg = Actual magnesium (% base saturation)

ACa = Actual calcium (% base saturation)

ANa = Actual sodium (% base saturation)

All others units = ppm

Table 4. Physical test for the inorganic modified soil.

	Undisturbed				Recompacted
Treatment	Ksat1	Wret2	Db3		Ksa	Wre	Db
Control	45.7	24.1	1.49		34.0	21.9	1.49
Bio-ceramic	43.9	23.7	1.48		37.7	20.9	1.48
Profile	46.8	27.2	1.44		40.7	23.5	1.44
Axis	44.5	27.3	1.42		33.4	24.9	1.42
Bio-Flex-A-Clay	39.5	23.6	1.55		27.5	20.3	1.55
LSD0.05	3.8	1.2	0.05		3.5	2.2	0.04

¹K_sat=Saturated water conductivity (cm/hr)

²W_ret=Water retention at -40cm water pressure (% of water based on dry soil)

³D_b=Soil dry bulk density (g/cm³)

⁴Recompacted according the undisturbed value

Figure 1. Soil moisture release curve for undisturbed samples of each amendment treatment completed in November 1997.

ISU Horticulture:Publications:1998 Turfgrass Report

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