POTASSIUM BALANCE AND
RELEASE KINETICS UNDER
RICE-RICE CROPPING SYSTEM
Dr. A.K. Pal, Professor
Dr. A.K. Dash, Assoc. Professor
Department of Soil Science and Agricultural Chemistry
College of Agriculture, OUAT, Bhubaneswar-3
Different forms of K in increasing
order of availability
ƒ
Mineral / structural K (Unavailable )
ƒ
Non exchangeable/fixed K ( difficultly
available/ slowly available)
ƒ
Exchangeable K (Easily available)
ƒ
Water soluble K (Readily available)
Exch. K
(on external surface)
Rapid and continuous exchange
Slow and Contigent
exchange
K in
solution
Fixed or reverted K
K definitely fixed
(Barbier, 1962)
Factors affecting availability of K in soils of Orissa
Effect of particle size and distribution
Effect of mineralogy and weathering
Effect of soil reaction
Effect of soil moisture regime
Effect of previous cropping and management
Effect of CEC and associated cations
Contribution from subsoil
Different forms of K in Orissa Soil
Broad Soil
Group
Total
K2O%
Non Exch.
Fixed K
(me/100g)
Exch. K
(me/100 g)
KSaturated
(%)
Water
soluble K
(me/L)
Textural
class
Laterite
Soils
0.3-1.2
(0.69)
0.10-0.91
(0.31)
0.06-0.30
(0.17)
1.30-4.80
(2.7)
0.008-0.08
(0.05)
Sandy
loam
to silty
loam
Red soil,
mixed red
& black
soil
1.62-6.03
(3.2)
0.20-0.97
(0.68)
0.10-1.10
(0.40)
0.75-14.90
(5.54)
0.025-0.27
(0.14)
Loam to
clay
Alluvial
soils
0.68-2.41
(1.32)
0.05-1.92
(0.85)
0.06-0.64
(0.26)
0.81-5.80
(2.35)
0.018-0.175
(0.07)
Sandy
loam to
clay
Coastal
saline
soils
1.77-3.01
2.49
0.18-1.45
(0.72)
0.14-1.60
(0.89)
3.0-6.19
(4.32)
0.30-1.60
(0.73)
Loam to
clay
Figures in parenthesis indicate average value
Mean annual yield, K-uptake, K balance in
the soil after 20 years of rice cropping
Treatments
100%N
100% NP
100% NPK
100%
NPK+FYM
150% NPK
N0P0K0
(Control)
Mean yield of rice(q/ha)
Mean annual
K-uptake
(kg/ha)
Annual
K-balance
(kg/ha)
Kharif
Rabi
20.95
22.52
29.82
34.81
20.50
27.98
32.10
37.59
84.00
90.00
137.00
167.00
-84.00
-90.00
-37.00
-47.00
30.13
15.60
34.00
13.99
157.00
56.00
-7.00
-56.00
Cumulative effect of treatments on NH4OAc extractable –K
over 20 years of rice-rice cropping
Tr.
No
Treatments
NH4OAc(mg/kg soil)
0-15 cm
layer
15-30 cm
layer
30-45 cm
layer
Total
1
150 % NPK
23
26
40
89
2
100% NPK
20
21
34
75
3
100% NPK+ Zn
20
20
36
76
4
100% NP
17
18
28
63
5
100% N
17
17
28
62
6
100% NPK +FYM
28
25
41
94
7
100% NPK(- S)
22
22
34
78
8
Lime+ NPK (STB)
26
29
39
94
9
Control
Initial
14
13
21
48
12.5
22
35.5
70
Cumulative effect of treatments on 1N HNO3 boiling(one time)
extractable–K over 20 years of cropping
Tr. Treatment
No
1N HNO3 (mg/kg soil)
0-15 cm
layer
15-30 cm
layer
30-45 cm
layer
Total
1
150 % NPK
125
125
133
430
2
100% NPK
107
96
138
351
3
100% NPK+ Zn
107
107
180
355
4
100% NP
73
85
148
279
5
100% N
83
93
141
304
6
100% NPK +FYM
99
87
121
305
7
100% NPK(- S)
100
101
128
340
8
Lime+ NPK
(STB)
128
108
119
395
9
Control
77
88
139
288
120
116.5
156.5
393
Initial
Cumulative effect of treatments on Non exchangable–K
over 20 years of cropping
(1N HNO3 - NH4OAc) (mg/kg soil)
Tr.
No
Treatment
0-15 cm
layer
15-30 cm
layer
30-45 cm
layer
Total
1
150 % NPK
102
99
140
341
2
100% NPK
87
75
114
276
3
100% NPK+ Zn
87
87
105
279
4
100% NP
56
67
93
216
5
100% N
66
76
100
242
6
100% NPK +FYM
71
62
108
241
7
100% NPK(- S)
78
79
105
262
8
Lime+ NPK
(STB)
102
79
120
301
107.5
94.5
121
323
Initial
Cumulative Effect of Treatments on Step-K and
constant rate-k after 40 cropping cycles
Tr.
No.
CR-K
(mg kg-1)
Step K
(mg kg-1)
Treatment
1
3
4
6
8
50 % NPK
150 % NPK
100 % NPK
100 % NP
100 % NPK +FYM
10 Lime + (soil test based)
Initial
0-15
cm
layer
15-30
cm
layer
30-45
cm
layer
0-15
cm
layer
15-30
cm
layer
30-45
cm
layer
71
98
84
43
72
79
88
84
51
54
85
105
108
74
97
16
17
16
15
16
18
18
18
16
17
23
25
24
22
24
96
96
74
97
108
111
17
17
19
20
25
26
Mean annual K application, K - uptake and K balance (kg ha-1)
of different treatments (14 cropping cycle)
Treatments
Mean annual
application of
K
100% NPK + Zn + B +
100
S
100% NPK + Zn + B
100
100% NPK + B + S
100
100% NPK + Zn + S
100
100% NPK + Zn + B +
100
S + FYM
100% NPK + Zn + B +
100
S + GM
100% NK + Zn + B +
155.6
S + Straw
Control
-
Mean annual
K-uptake
Mean annual
balance
121.2
-21.2
118.0
118.1
113.6
118.0
-18.0
-18.1
-13.6
-18.0
109.4
-9.4
109.8
45.8
61.7
-61.7
PHYSICO- CHEMICAL PROPERTIES OF SOILS
Block
No. of
samples
pH
OC (%)
CEC cmol
(p+) kg-1)
Clay (%)
Narasinghpur
21
5.14-8.1
0.44-1.40 8.71-22.39
10.7-34.1
Baramba
22
4.96-8.3
0.51-1.14 14.74-44.44 12.4-43.8
Athagarh
22
4.66-5.97 0.33-1.38 9.89-35.44
90.0-41.0
Tigiria
20
5.09-7.44 0.33-1.22 9.09-39.39
10.4-35.0
MEAN VALUE OF DIFFERENT FORMS OF
POTASSIUM
Forms of K (mg kg-1 soil)
Block
NH4 OAc
Non
extractable exchangeable
Lattice
Total
Narasinghpur
10-380
130-900
750-1620
950-3000
Baramba
22-125
230-925
220-1570
60-2050
Athagarh
45-170
155-845
380-1850
900-2900
Tigiria
45-125
145-740
700-2360
1000-2900
Correlation coefficient among different
forms of K
Form of potassium
Water
soluble K
Exchangeable- K
Available
K
NonExch. K
Lattic K
Total K
Water soluble K
1.000
Exchangeable K
0.714** 1.000
Available K
0.812** 0.989**
1.000
Non – Exch. K
0.53/**
0.365
0.421
1.000
Lattice K
0.381
0.200
0.279
0.381
Total K
0.517*
0.322
0.300
0.671** 0.940** 1.000
* Significant at P = 0.05, ** - Significant at P = 0.01
1.000
Release of K extracted by boiling with 1N HNO3
1st
2nd
3rd
K released (mg kg-1 soil)
4th
5th
6th
7th
8th
9th
10th
150
325
375
200
250
175
675
150
175
150
175
375
225
175
475
275
425
400
275
700
325
50
175
325
100
150
150
525
100
95
75
120
150
150
64
350
175
325
325
175
450
96
44
74
106
8
64
75
122
75
80
56
76
54
75
54
104
58
104
112
72
188
70
40
54
96
40
50
52
80
60
64
46
52
36
56
48
84
42
70
92
56
136
56
36
28
46
28
26
44
28
46
40
34
20
24
26
42
38
12
28
46
36
56
48
36
28
46
28
26
44
28
46
40
34
20
24
26
42
38
12
28
46
36
56
48
36
28
46
28
26
44
28
46
40
34
20
24
26
42
38
12
28
46
36
56
48
Sample
No.
N1
N2
N3
N4
N5
N6
N7
N8
N9
N10
N11
N12
N13
N14
N15
N16
N17
N18
N19
N20
N21
36
36
62
30
44
46
40
56
60
40
38
24
42
44
66
30
50
70
48
104
50
36
28
52
28
28
44
30
50
56
34
28
24
36
42
48
16
38
58
40
90
48
36
28
46
28
26
44
28
46
40
34
20
24
26
42
38
12
28
46
36
56
48
CR-K Total
step K
36
28
46
28
26
44
28
46
40
34
20
24
26
42
38
12
28
46
36
56
48
140
524
740
288
430
278
1312
215
290
197
369
519
428
283
899
524
844
781
450
1332
709
Total
extract
able K
500
804
1200
568
690
718
1592
675
690
537
869
759
688
703
1279
644
1124
1241
810
1892
1189
Correlation coefficient of K release parameter with
forms of K
NH4OAC-K
NonExch. K
Lattice
K
Total K
NHOAC-K
1.000
Non exch-K
0.821**
1.000
Lattic K
0.448*
0.418
Total K
0.689**
0.733** 0.921** 1.000
CR-K
0.510*
0.249
Total Steb K
0.736**
Total
0.810**
Extractable K
CR-K
Total
step K
Total
extractable
K
1.000
0.478*
0.489*
1.000
0.969** 0.399
0.710**
0.206
1.000
0.944** 0.498*
0.781**
0.676
0.959** 1.000
Changes in the values of K release parameters with
depth in the profiles
Genetic
horizon
Depth (cm)
Total
extract. K
Total step K
CR – K
% of non-exch. K + Lattice K
Mg kg-1
Ap
B 21t
B 22t
B 23t
C
0-11
11-52
52-88
88-115
115-150
Ap
B 21t
B 22t
B 23t
0-14
14-42
42-90
90-172
Ap
B 21t
B 22t
B 23t
0-14
14-27
27-60
60-150
Ap
B 21t
B 22t
C
0-14
14-32
32-84
84-155
Total
extract K
Profile – 2 Upper ridge (Aridic Kanhapulstlfs)
1365
1325
04
54.9
2008
1768
24
74.9
2228
1908
32
76.8
2466
2066
40
88.4
2505
2105
40
96.9
Profile – 3 Mid upland (Aridic Kanhaplustalfs)
1348
1188
16
63.6
2085
18545
24
77.1
2776
2216
56
95.7
2882
2282
60
85.0
Profile – 4 Medium land (Aridic Kanhaplustalfs)
1432
1352
08
83.4
1629
1389
24
76.7
2106
1786
32
87.4
2709
2069
64
86.7
Profile – 5 Medium valley alnd (Aridic Ustochrepts)
1109
909
20
82.5
1390
1070
32
97.2
1787
1587
20
63.9
2185
1865
32
73.2
Total Step
K
CR-K
53.3
66.6
65.8
74.1
81.4
0.2
0.9
1.1
1.4
1.5
56.0
68.2
76.4
67.3
0.8
0.9
0.9
0.8
78.8
65.4
74.1
66.2
0.5
1.1
1.3
2.0
67.6
74.8
56.8
62.5
1.5
2.2
0.7
1.1
Relationship of the K-release with forms of
K (n = 17)
K – release
parameters
Clay
NonLattice Total K
exchangea
K
ble K
Total extractable K
0.96**
0.73** 0.84** 0.95**
Total step K
0.95**
0.79** 0.89** 0.94**
CR-K
0.80**
NS
0.58* 0.81**
CONCLUSION
™ Potassium dose should be increased to sustain the crop
productivity as well as soil health.
™ Straw recycling should be advocated for better
management of K deficiency in rice-rice cropping system.
™ Dynamic equilibrium among different forms of K is
maintained in soil.
™ Higher amount of step K indicates more release of K from
non-exchangeable form under stress condition.
™ Higher value of extractable K in soil indicates greater Ksupplying capacity.
™ Higher value of CR-K indicates adequately supply of K to
the plant.
™ Step K is highly correlated with clay content of soil.
™ K-release characteristics revealed that IN HNO3 can
serve as a good index of K availability from nonexchangeable and lattice K.