Forms and Dynamics of Soil Potassium in Acid Soil in the Wolaita Zone of Southern Ethiopia
Table 4
Thermodynamic parameters of the soils as influenced by locations and land use systems.
Location
Land use
I (μ)mol L−1
[K+] (x10−3)
γK
Γ (Ca + mg)
aK+(x 10−3)
a(Ca + M g2+) (x 10−3)
ARK
(ΔF) cal mol−1
±ΔK (cmol kg−1)
ARek (mol L−1)1/2
PBC0k [cmol kg −1/(mol L−1) 0.5]
Sodo Zuria
Enset-coffee
0.001935
6.76
0.9506
0.43
6.42
0.817
0.22
−896.71
0.09
0.072
1.26
Crop land
0.006837
7.10
0.9078
0.21
6.44
0.294
0.04
−1906.32
0.31
0.074
1.75
Grass land
0.005418
8.32
0.9183
0.25
7.64
0.400
0.38
−571.10
0.12
0.071
1.48
Damot Gale
Enset-coffee
0.001419
7.66
0.9569
0.49
7.32
0.931
0.24
−842.20
0.05
0.062
0.80
Crop land
0.004128
7.57
0.9274
0.29
7.02
0.435
0.33
−323.83
0.11
0.069
1.59
Grass land
0.005547
8.14
0.9164
0.24
7.45
0.336
0.41
−528.03
0.10
0.074
1.35
Damot Sore
Enset-coffee
0.002709
7.85
0.9410
0.37
7.38
0.592
0.30
−713.03
0.10
0.066
1.51
Crop land
0.004257
7.22
0.9264
0.29
6.68
0.555
0.29
−733.10
0.11
0.066
1.66
Grass land
0.002967
7.53
0.9382
0.36
7.06
0.612
0.29
−733.10
0.11
0.071
1.54
Boloso Sore
Enset-coffee
0.007095
7.65
0.9061
0.20
6.93
0.360
0.43
−2076.6
0.11
0.064
1.71
Crop land
0.005547
8.13
0.9164
0.24
7.45
0.312
0.38
−573.03
0.09
0.049
2.00
Grass land
0.006708
7.00
0.8978
0.21
6.28
0.336
0.34
−693.61
0.12
0.067
1.79
Means
0.004547
6.19
0.92
0.29
7.00
0.49
0.30
−884.1
0.11
0.07
1.53
CV (%)
6.60
7.57
1.12
9.54
6.25
6.22
7.65
−30.68
9.20
6.57
7.59
P Value
<0.001
0.0610
<0.001
<0.001
0.210
<0.001
<0.001
0.002
<0.001
<0.001
<0.001
LSD (5%)
0.001
NS
0.008
0.04
NS
0.10
0.06
272.92
0.03
0.001
0.09
I= ionic strength, ARe k (mol L−1)1/2 = equilibrium activity ratio; PBCK: potential buffering capacity [cmol kg−1/(mol L−1)0.5],[K+] = K concentration (mol L−1), γK = activity coefficient of K, aK = activity of K (mol L−1), γCa + Mg = activity coefficient of Ca + Mg, a(Ca2+ + Mg2+) = activity of Ca + Mg, ARK = activity ratio of K, ±ΔK = gain/loss of K (cmol kg−1), NS = nonsignificant.
