1999 Iowa Turfgrass Research Report


Effects of Inorganic Soil Amendments on Sand-based Media

 

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

 

ABSTRACT

 

Inorganic soil amendments have been suggested for use in turf to alleviate soil compaction, to increase the water retention and hydraulic conductivity, and to improve many other soil physical properties. No single soil conditioner can have all those properties. They, therefore, should be used in a site- and case-specific way. This study was to determine the effects of four different inorganic soil amendment materials Bio-ceramic, Profile, Axis, and Bio-Flex-A-Clay on the soil hydraulic parameters of a sand-based media. The inorganic materials were added to a USGA sand-based green at 15% v/v during construction in 1996. The study was conducted during the 1997 and 1998 seasons. A laboratory study using a peat amendment and a pure sand control was also conducted in the spring of 1999. Data collected on the field areas included saturated hydraulic conductivity (Ksat), water retention, water release curves, bulk density, and total porosity on both undisturbed and recompacted samples collected from the treated plots one and two years after establishment. The Profile treatment had significantly higher cation exchange capacity (CEC) than the control in both years. Bio-ceramic had a higher CEC and Bio-Flex-A-Clay had lower CEC than the control in 1997. Profile increased the Ksat significantly in the recompacted and undisturbed samples in 1998. Axis increased water retention in both recompacted and undisturbed samples. Ksat of all treated plots was reduced by 75% in November of 1998. The Ksat values in the spring of 1999 increased from the low levels of 1998 by 19.2% (Bio-Flex-A-Clay), 43.5% (control), 58.6% (Bio-ceramic), 72.1% (Profile) and 81.7% (Axis). The changes of Ksat over the winter may have been induced by freezing and thawing that occurred over the winter. This hypothesis was further tested in the laboratory in a freeze-and-thaw study conducted in 1999. The bulk density of sand mixed with Bio-Flex-A-Clay, peat, Axis and Profile was decreased by 10.7%, 7.2%, 2.5% and 2.2% respectively following a freeze-and-thaw cycle. The decrease of bulk density in the control and in sand treated with Bio-ceramic was negligible.

 

Table 1. Soil test results for the inorganic soil modification study1 (Sand-based green 1998)

Treatments

CEC
PH
SS
Na
OM
NIT
P
K
Mg
Ca

Control

8.3
8.3
0.08
19.7
0.5
1.3
3.0

25

80

1486

Bio-ceramic

8.1
8.3
0.08
18.0
0.5
2.3
4.0

25

78

1454

Profile

8.9
8.2
0.08
19.7
0.5
1.3
4.3

49

114

1534

Axis

8.1
8.3
0.08
18.3
0.4
1.3
4.7

25

73

1478

Bio-Flex-A-Clay

7.8
8.2
0.11
17.7
0.6
1.7
3.0

22

79

1414

 

 

 

 

 

 

 

 

 

 

 

LSD0.05

0.6
NS
NS
NS
NS
NS
NS

4

12

NS

 

 

 

 

 

 

 

 

 

 

 

 

S
Zn
Mn
Cu
Fe
B
AK
AMg
ACa
ANa

Control

1.0
0.8
2.8
0.6
6.57
0.3
0.8

8.1

90.1

1.0

Bio-ceramic

1.0
0.9
2.8
0.9
6.57
0.3
0.8

8.0

90.2

1.0

Profile

1.0
0.7
2.5
0.6
7.87
0.3
1.4

10.8

86.9

0.9

Axis

1.0
0.7
2.5
0.7
7.23
0.3
0.8

7.5

90.8

1.0

Bio-Flex-A-Clay

1.7
0.9
2.9
0.7
6.13
0.3
0.7

8.3

90.0

1.0

 

 

 

 

 

 

 

 

 

 

 

LSD0.05

0.5
NS
0.3
NS
NS
NS
0.2

0.7

0.8

NS

1NS= Not significant at 0.05 level AK= Actual Potassium (% base saturation)

CEC= Cation Exchange Capacity (meg/100g) AMg= Actual Magnesium (% base saturation)

SS= Soluble salts (mmhos/cm) ACa=Actual Calcium (% base saturation)

Na=Sodium (ppm) ANa= Actual Sodium (% base saturation)

OM=Organic matter (%)

NIT=Nitrite N (ppm)

Iowa State University ISU Horticulture:Publications:1999 Turfgrass Report College of Agriculture