Environmental Engineering Reference
In-Depth Information
It provides specific information about the types and amounts of nutrients
being taken up by specific turf species, of which the soil test provides
only a rough idea. Combining soil and plant-tissue tests provides a
complete picture of soil fertility. Leaf tissue should always be tested
before establishment of a more complex turf area, such as a golf course,
athletic field, tennis court or even playground.
The results of a soil test can only be properly interpreted if the soil
sample they are based on was representative. Soil samples can be taken at
any time of the year, but it is better to avoid times shortly after excep-
tionally heavy rainfall. Samples should be collected with a soil probe or
any other tool that is able to cut to a depth of 15 cm. If the soil is uniform
in texture and colour and has not received recent applications of fertil-
izer, organic amendments or lime, 10-15 samples from random locations
are sufficient for an area the size of a large lawn, park lawn or football
field. All the samples should be placed in a large container and mixed
well. Finally, about 0.5 kg of this composite sample should be sent to the
laboratory. Separate composite samples should be assembled from areas
that differ in soil texture or colour and in areas that have received recent
amendments. In many countries, soil test laboratories present results as
numerical values that represent sufficiency levels for a particular turf-
grass. In other countries, only general sufficiency levels are presented.
Tables 5.2 and 5.3 present sufficiency ranges of nutrients in soil and leaf
tissue.
Table 5.2. Sufficiency ranges of nutrients in the soil.
Amount (kg/ha) represented by each soil-test designation
Nutrient
Low
Medium
High
Very high
Phosphorus
<15
15-30
30-120
>120
Potassium
<100
100-150
150-300
>300
Calcium
<500
Magnesium
<40
Sulphur
<15
15-50
>50
Boron
<0.5
0.5-1.5
>1.5
Copper
<0.5
0.5-5
>5
Iron
<15
15-120
>120
Manganese
<10
10-50
>50
Zinc
<2
2-5
>5
Source: J.B. Jones, Jr., B. Wolf and H.A. Mills (1991) Plant Analysis Handbook. Micro-Macro
Publishing, Athens, Georgia.
