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Berlin Environmental Atlas

01.06 Soil-Scientific Characteristic Values (Edition 2006)

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01.06.8 Sum of Interchangable Basics Cation of Topsoil (S-Value)


Description

Interchangable cations of soil usually subdivided into acidic and basic cation. Acidic cations such as hydrogen ions (H-ion) causes hydrolysis, so release H-ion,above all Al; the sum is called as H-value. Basic cation are in first line Ca2+, K+ Mg2+ and Na+, in agricultural soil (after fertilizing) also, NH4+ (where mostly Ca2+ is more than 80 % dominant). The sum of it makes S-value. Its concentration could be givenin molc/kg, quantity in molc/m². Percentage share of S-Value of Interchangable cation is named as Alkaline Saturation.

S-value describes the quantity from soil related to plants nutrients cations and is also important for fertility of soil.

Methodology

Quantity of basic interchangable Ions (S-Value) for topsoil (here 0 - 3 dm) can be calculated through multiplication of effective cation interchagable capacity (KAKeff) with Alkaline saturation, considering storage thickness and coarse soil share.

Calculation of effective cation interchangable capacity is given in map 01.06.09. Alkaline saturation can therefore be calculated from pH value (CaCl2).

Ascertainment is accomplished using the pH value typical of the location of the topsoil,(cf. map 01.06.07) and the alkaline saturation according to Table 1. Then a linear interpolation between these pH stages of this table is carried out.

Table 1: Relationship between Alkaline Saturation (BS) in % and pH (CaCl2) of Mineral Soil Zones in Berlin
pH
(CaCl2)
BS
[%]
3 2
3.1 3
3.2 4
3.3 5
3.4 6
3.5 7
3.6 9
3.7 11
3.8 13
3.9 15
 
pH
(CaCl2)
BS
[%]
4 18
4.1 20
4.2 23
4.3 25
4.4 28
4.5 31
4.6 34
4.7 38
4.8 41
4.9 44
 
pH
(CaCl2)
BS
[%]
5 47
5.1 50
5.2 53
5.3 56
5.4 60
5.5 63
5.6 66
5.7 69
5.8 72
5.9 75
 
pH
(CaCl2)
BS
[%]
6 77
6.1 80
6.2 82
6.3 85
6.4 87
6.5 89
6.6 91
6.7 93
6.8 95
6.9 96
 
pH
(CaCl2)
BS
[%]
7 97
7.1 98
7.2 98
7.3 98
7.4 99
7.5 99
7.6 99
7.7 100
7.8 100
7.9 100
Table 1: Relationship between Alkaline Saturation (BS) in % and pH (CaCl2) of Mineral Soil Zones in Berlin (Grenzius 1987)

In table 2 S-values are classified into 1-10 levels (extremely low - very high).

Table 2: Gradiation of the S-Vvalue
S-Value
[molc/m²]
Level Designation
<1 1 extremly low
1 - <2 2 very low
2 - <3,5 3 moderate to very low
3,5 - <5 4 moderate low
5 - <10 5 low
10 - <25 6 moderate
25 - <50 7 medium
50 - <100 8 moderate high
100 - <200 9 high
>200 10 very high
Table 2: Gradiation of the S-Value (Schlichting et al. 1995, Gerstenberg, Faensen-Thiebes 2005)

Subdivision of low level values have marginal difference,to show for evaluation of function "living space for near naturalness and seldom plant societies" necessarly accurate level of poor nutrient soil.

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