Cyathodium bryophyte: morphology, anatomy, reproduction etc.
dynamics of soil potassium
1. Credit Seminar on
STUDIES ON DYNAMICS OF SOIL POTASSIUM AND
EFFECT OF DIFFERENT FORMS ON K AVAILABILITY TO
CROPS.
P. SOWMYA
RAM/2018-91
Dept of Soil science
PROF JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY
College of Agriculture, Rajendranagar,PJTSAU,Hyderabad-30
Course-in-charge: Dr. G. Padmaja
Professor and Head
Dept of SSAC
2. INTRODUCTION - POTASSIUM
• Potassium is the 3rd most important major nutrient in plant Nutrition.
• Potassium is the most abundant macronutrient in soils. It is also the
seventh most common element in the lithosphere which contains on
average 2.6% potassium.
• The total potassium content of Indian soils varies from 0.5 to 3.0%.
• Total potassium present in soils, more than 98% occurs in primary and
secondary minerals and the rest occurs in either fixed or non
exchangeable form or exchangeable (adsorbed) form or in soil solution.
• The role of potassium in increasing the yield of crops and improving the
quality of produce is the agenda of soil scientists.
3. ROLE OF POTASSIUM TO INCREASE CROP
YIELD
• Increases growth and improves drought
resistance for crop.
• Activates atleast 60 enzyme systems.
• Maintains turgor; reduces water loss and wilting.
• In photosynthesis and food formation.
• Reduces respiration, preventing energy losses.
• Enhances translocation of sugars and starch.
• Improves weight and quality of grain.
• Builds cellulose and reduces lodging.
• To helps for crop pest and disease resistance.
14. TABLE 6: EFFECT OF CONTINUOUS USE OF MINERAL FERTILIZERS
AND SOIL AMENDMENTS ON YIELD AND K UPTAKE OF MAIZE
TREATMENT GRAIN YIELD ( t ha-1 ) K UPTAKE ( kg ha-1)
T1 control 0.58 6.9
T2 100% N 0.00 0.00
T3 100% NP 3.02 21.3
T4 100% NPK 4.39 37.7
T5 100% NPK +FYM 6.02 53.9
T6 100% NPK+Lime 5.30 42.7
T7 100% NPK +Zn 4.31 32.5
T8 100% NPK(-S) 2.08 18.2
T9 50% NPK 3.26 28.8
T10 150% NPK 4.76 38.7
LSD(P=0.05) 0.54 3.9
Palampur Sood et al.2008
15. Exch. K
1%
Non-
exch.K
10%
Lattice.K
89%
Inorganic Exch.K
1%
Non-
exch.K
3%
Lattice K
96%
Rice straw
Exch.K
1%
Non-
exch.K
5%
Lattice.
K
94%
FYM
Exch.K
1%
Non-
exch.K
4%
Lattice.K
95%
Rice straw + FYM
Fig 4: Exchangeable (Exch.K), non-exchangeable (Non-exch.K) and lattice K as a proportion of
total K in surface soil (0-7.5 cm depth).
Yadav et al., 2018
PAU, Ludhiana
16. TREATMENTS POTASSIUM FRACTIONS (mg kg-1)
WS.K EXC.K NON EXC.K LATTICE.K TOTAL K
T1 - 30:75:00 kg
NPK ha-1
26 139 549 10047 10762
T2 - 30:75:30 kg
NPK ha-1
27 143 560 10195 10925
T3 - 30:75:60 kg
NPK ha-1
30 146 572 10351 11098
T4 - 30:75:90 kg
NPK ha-1
34 152 586 10535 11305
SE(m)± 0.43 4.03 1.76 29.68 27.96
CD at 5% 1.31 12.07 5.32 89.45 84.28
TABLE 7 : EFFECT OF DIFFERENT LEVELS OF POTASSIUM ON
ITS FORMS AT HARVEST OF SOYBEAN
Akola, Maharastra Lokya et al, 2018
17. Treatments Contribution of non-exchangeable K to total K uptake
Yield (q ha-1) Contribution of non-
exchangeable K to
total K uptake
(kg/ha)
Percent
Contribution
(%)
KUE (%)
Grain straw
T1 14.19 21.02 22.39 84.87 -
T2 15.76 25.06 11.53 29.29 5.24
T3 16.56 26.37 5.06 10.24 3.95
T4 17.21 27.04 2.60 9.87 3.36
TABLE 8: CONTRIBUTION OF NON-EXCHANGEABLE K TO
TOTAL K UPTAKE
Akola, Maharastra. Lokya et al, 2018.
18. POTASSIUM FIXATION
NON EXCHANGEABLE K
SOIL SOLUTION / EXCHANGEABLE K
Factors affecting K Fixation
1.Clay minerals
2.Soil pH
3.Wetting and Drying
4.Potassium Fertilization
19. TABLE 9 : LEACHING FROM TWO SOILS AFFECTED BY APPLICATION OF
ORGANIC AND INORGANIC FERTILIZERS UNDER FLOODED CONDITION
TREATMENT TOTAL K
ADDED (mg)
TOTAL K LEACHED
(mg/Column)
% OF K APPLIED
Sandy Loam Loam Sandy Loam Loam
RICE STRAW 130.4 58 (18.8) 33 (11.9) 14.4 9.2
WHEAT STRAW 43.6 40.7 (1.5) 24.1 (3.0) 3.4 6.8
POULTRY MANURE 55.3 48.8 (9.6) 26 (4.9) 17.3 8.8
FYM 102.7 41 (1.8) 23.5(2.4) 1.8 2.3
GREEN MANURE 67.3 41.3 (2.1) 23.1(2.0) 3.1 2.9
FERTILIZER K 39.3 45.4 (6.2) 29.8 (8.7) 15.8 22.2
CONTROL - 39.2 21.1 - -
Ludhiana, Punjab Singh et al., 2005
*Amount of K leached (Total – Control)
20. TABLE 10 : WATER SOLUBLE K IN UPLAND MOISTURE
CONDITIONS
TREATMENT SOIL TYPE
loam (mg/kg) sandy loam (mg/kg)
RICE STRAW 15 9
WHEAT STRAW 10 8
POULTRY MANURE 14 8
FYM 12 8
GREEN MANURE 14 10
FERTILIZER K 12 10
CONTROL 10 6
CD 3.8 2.7
Ludhiana, Punjab Singh et al., 2005
21. LANDUSE SYSTEM WS K EX K NE K MINERAL K TOTAL K FIX : EXC K
Agri - Rice 12.1 137.5 228.8 1.31 1.35 1.66
Agri - Tobacco 13.6 65.4 205.8 1.36 1.39 3.16
Horti – Arecanut 14.8 120.7 303.4 0.99 1.04 2.51
Silvi - Eucalyptus 12.9 104.5 303.1 1.15 1.20 2.90
Control 11.9 64.4 168.1 1.23 1.26 2.63
TABLE 11: POTASSIUM FIXATION CAPACITY OF SURFACE SOIL
SAMPLES UNDER DIFFERENT LAND USE SYSTEMS
LANDUSE SYSTEM BWD( mg/kg) AWD(mg/kg) K FIXED[Cmol (p+) kg-1] % K fixed
Agri - Rice 1155 1046 0.27 10.7
Agri - Tobacco 1138 984 0.39 15.4
Horti – Arecanut 1157 967 0.48 18.8
Silvi - Eucalyptus 1129 883 0.62 24.5
Control 1288 1063 0.57 22.4
Gurumurthy and Prakasha, 2011
Karnataka
22. TABLE 12: CORRELATION BETWEEN UPTAKE OF K AND DIFFERENT K
FORMS IN SOIL
Stage Forms of K
Water Soluble Exchangeable Hcl Soluble Non
Exchangeable
0-15 15-30 0-15 15-30 0-15 15-30 0-15 15-30
Stolonization 0.48 0.36 0.50 0.40 0.39 0.38 -0.10 0.21
Tuberisation 0.62* 0.74** 0.69** 0.54* 0.67*
*
0.59* -0.43 0.29
Harvest 0.56* 0.58* 0.90** 0.83** 0.79*
*
0.85** 0.64* -0.30
Subehia et al., 2003
Palampur, Himachal Pradesh
23. Correlation among different forms of soil Potassium
Soil
Properties
Forms of Potassium
Water
soluble
Exchangeable Available Non-
Exchangeable
Lattice Total
Sand 0.17 -0.176 -0.168 0.205 0.453* 0.436*
Silt -0.09 -0.028 -0.029 -0.306 -0.184 -0.200
Clay -0.164 0.249 0.240 -0.184 -0.447* -0.413*
pH -0.230 -0.098 -0.100 -0.249 -0.362* -0.375*
EC 0.411* 0.518** 0.514** 0.236 0.359 0.402*
Organic
Carbon
0.091 0.171 0.171 0.058 -0.017 0.002
Free CaCO3 -0.041 -0.211 -0.206 0.046 0.117 0.159
Kaskar et al., 2001
Dapoli, Maharashtra
24. TABLE 13: QUANTITY INTENSITY RELATIONSHIP IN
AVAILABILITY OF POTASSIUM
• Beckett (1964)
• The Theory is based on exchange reactions
between Ca, Mg, and K.
• The Q/I concept is used for predicting the
status of potassium in soils
• It is the quantity relationship between
exchangeable K (Q quantity) and the activity
of potassium in the soil solution (I intensity).
25. Fig 6: A typical Q/I relationship showing different parameters
in relation to potassium availability in soils.
• ∆K = Amount through which the soil
gains or losses potassium in bringing
equilibrium (Q, quantity factor).
• ARK = Activity ratio of potassium (I,
intensity factor).
• ARK
e = Activity ratio of potassium at
equilibrium
• ∆Kex = Exchangeable or labile pool of
potassium
• Ksp = Specific sites for potassium
• PBCK = Potential buffering capacity
26. TABLE 14: FORMS OF POTASSIUM IN KHAMMAM SOILS OF
ANDHRA PRADESH
VILLAGE TEXTURE WS K EX K NE K TOTAL K
Vasanthavada Sand 37.3 117.5 883 19680
Kunavaram Loamy Sand 35.4 148.8 608 13607
Narsapuram Sandy Loam 23.9 130.9 575 18421
N.P.Banjar Sandy Loam 44.2 276.6 1009 15755
Vaddigudem Clay Loam 11.3 135.3 378 8233
Velerupadu Silty Clay Loam 19.8 330.2 914 9234
Amaravaram Silty Clay Loam 18.2 259.1 676 10513
Kukunur Clay 15.8 358.9 1532 11883
Khammam Rao and Murthy, 2007
28. TABLE 16: EFFECT OF K RATES ON DIFFERENT K FRACTIONS
K LEVEL(Kg ha-1) WSK EX.K AV.K HNO3 K NEK
mg/Kg
0 11 40 52 430 378
25 16 59 75 487 412
50 17 61 79 509 430
75 20 68 89 498 409
100 21 74 95 518 423
CD(P=0.05) 5 8 8 20 14
TABLE 17: EFFECT OF K RATES ON Q/I PARAMETERS OF K
K LEVEL(Kg ha-1) KL K0 KX AreK(×10-3) PBC K[cmol(p+)kg-1] ×10-3
cmol(p+)kg-1
0 0.10 0.06 0.04 2.85 28.35
25 0.13 0.09 0.04 2.99 35.20
50 0.20 0.12 0.08 3.52 41.19
75 0.26 0.18 0.08 4.91 47.02
100 0.30 0.23 0.07 7.69 38.18
CD(p=0.05) 0.06 0.06 NS 1.31 NS
Bhubaneswar, Orissa Byju et al., 2002.
29. FIG 7: POTASSIUM RELEASING POWER OF DIFFERENT SOIL
TYPES IN PULSE GROWING REGIONS OF INDIA
Kanpur, Uttar
Pradesh
Rao et al., 2003
(Alfisol) (Vertisol)
(Inceptisol)
30. FIG 8: K RELEASE IN DIFFERENT TYPES OF SOILS
Kanpur, Uttar
Pradesh
Rao et al., 2003
31. • CONCENTRATION RATIO
OF POTASSIUM IN
SATURATION EXTRACT (
CRK
Se )
• BUFFERING CAPACITY (
BCK
Se )
• UNIFIED SOIL QUANTITY
INTENSITY CHARACTER
(USQI factor)
PARAMETERS DERIVED FROM K CONCENTRATION IN
SATURATION EXTRACT
CRK
Se = CK/(Ca+ Mg)0.5
BCK
Se = Kam/ CRK
Se
USQI Factor = Kam ×ρ CRK
Se
ρ= -ve log of CRK
Se
32. TABLE 18: PARAMETERS DERIVED FROM CONCENTRATION OF K IN SATURATION
EXTRACT AND 1N NH4OAC EXTRACTABLE K OF RANGA REDDY DISTRICT
S.No Village Composition of the
saturation extract
CRK
Se (me
l-1)
Kam in
me
100g-1
BCK
Se (me 100g-
1) /(me l-1)0.5
USQI Factor (me
100g-1)0.5*(me l-
1)0.5
K me l-1 Ca + Mg in me l-1
1 Chenvelli 0.24 7.6 0.086 0.48 5.62 0.741
2 Kathagadi 0.23 6.4 0.089 0.40 4.48 0.663
3 Masireddypalli 0.27 5.4 0.118 0.17 1.47 0.387
4 Muduchinthala
palli
1.41 13.8 0.378 1.14 3.02 0.451
5 Keesara 0.32 6.2 0.128 0.64 5.01 0.715
6 Bogaram 0.39 6.0 0.158 0.32 2.04 0.455
7 Manchal 0.38 22.2 0.081 0.32 3.99 0.620
8 Kongarakonal 0.40 9.2 0.133 0.58 4.35 0.666
9 Kocharam 0.56 22.0 0.119 0.42 3.50 0.597
10 Rajendranagar 0.26 7.0 0.100 0.36 3.56 0.567
Range 0.23-
1.41
5.4-22 0.081-
0.378
0.21-
1.14
1.47-12.36 0.387-1.104
Chaitanya, 2016
Rajendranagar
33. TABLE 19: ESTIMATION OF POTASSIUM IN SOILS THROUGH CHEMICAL
EXTRACTANTS
METHOD COMPOSITION OF EXTRACTANT SOIL:
EXTRACTA
NT RATIO
SHAKIN
G TIME
(MIN)
REFERENCE
Distilled water Distilled water 1: 10 60 Grewal and Kanwar (1966)
1 N NH4OAC 1 N Ammonium Acetate at pH (7.0) 1 : 5 5 Stanford and English (1949)
0.01 M CaCl2 0.01 M CaCl2 1: 10 120 Houba et al. (1990)
1 N HNO3 1 N HNO3 1 : 10 10 DeTurk. 1941
AB-DTPA 1 M NH4HCO3 + 0.005 M DTPA 1 : 2 15 Soltanpour and Schwab
(1977
0.03M NaBPh4 sodium tetraphenylboron 1 : 6 15 Scott et al. (1960)
1.38 N H2SO4 1.38 N H2SO4 1 : 10 15 (Hunter and Pratt, 1958)
34. TABLE 20: EXTRACTION OF DIFFERENT FORMS OF K (mg kg-1) USING
VARIOUS EXTRACTANTS IN SOILS OF RANGA REDDY DISTRICT
S.No Village Distilled water
extractable K
1N NH4OAc
extractable K
1.38N H2SO4
extractable K
0.03M Na BPh4
extractable K
Boiling 1HNO3
extractable K
1 Chenvelli 18 188 396 81 1100
2 Kathagadi 20 156 376 81 1000
3 Masireddypalli 45 68 356 82 850
4 Muduchinthalapal
li
56 446 500 82 2340
5 Keesara 25 250 412 81 1700
6 Bogaram 51 126 376 83 1210
7 Manchal 25 126 380 82 1140
8 Kongarakonal 57 226 416 82 1300
9 Kocharam 25 163 388 83 1690
10 Rajendranagar 24 139 396 81 1300
Range 18-57 68-446 356-500 81-85 850-2340
Chaitanya, 2016
Rajendranagar
39. TABLE 24: EFFECT OF DIFFERENT TREATMENTS ON AVAILABLE K
AFTER 36 CYCLES
TREATMENTS AVAILABLE K CHANGES
FROM
INITIAL
TOTAL K
ADDED
TOTAL K
UPTAKE
K BALANCE
50% NPK 247 -123 830 5113 -4283
100% NPK 269 -101 1660 6974 -5314
150% NPK 284 -86 2490 8284 -5794
100%NPK
+FYM
295 -75 5703 9134 -3431
CONTROL 202 -168 5113 1994 -1994
Jabalpur, Madhya Pradesh Sawarkar, 2013
Initial (1972) : 370 kg/ha
40. TABLE 26: DIFFERENT FORMS OF K (mg/kg) INFLUENCED BY
MANURES AND FERTILIZERS
TREATMENTS WSK EXK AVAIL.K NEK TOTAL K
CONTROL 4 45 49 241 6012
100 % N 5 45 50 299 6987
100 % NP 6 44 50 315 6026
50 % NPK 5.7 49.3 55 342 6375
100% NPK 6 56 62 337 6812
150 % NPK 8 61 69 339 6987
100 % NPK-S 6 55 61 298 6415
100% NPK + Zn 7 55 62 369 6638
100 % NPK + FYM 10 57 67 377 7262
CD (P=0.05) NS 7.2 9.2 108 905
INITIAL 10 48 58 355 6467
Pantnagar, Uttarakhand Singh et al., 2014
41. TABLE 25: K BALANCE AFFECTED BY 40 YEARS OF APPLICATION OF OM
AND FERTILIZERS
TREATMENT K ADDED (kg/ha) K
REMOVE
D(kg/ha)
K
BALANCE
(kg/ha)
K
BALANCE
(kg/ha/Yr)
FERT OM IW TOTAL
CONTROL 0 - 2000 2000 3911 -1911 -47.8
100 % N 0 - 2000 2000 6845 -4845 -121.1
100 % NP 0 - 2000 2000 7088 -5088 -127.2
50 % NPK 1460 - 2000 3460 6847 -3027 -75.7
100% NPK 2920 - 2000 4920 7171 -2251 -56.3
150 % NPK 4380 - 2000 6380 7354 -974 -24.4
100 % NPK-S 2920 - 2000 4920 7224 -2304 -57.6
100% NPK + Zn 2920 - 2000 4920 7645 -2725 -68.1
100 % NPK + FYM 2920 4800 2000 9720 8218 +1502 +37.6
Pantnagar, Uttarakhand Singh et al., 2014
IW Contains 5 mg K L-1. Hence, annual addition of K is 50 kg/ha/yr.
FERT – Fertilizer, OM – Organic Manure, IW – Irrigation Water.
45. CONCLUSIONS
• Recycling through crop residue management holds a great promise
in this respect as 80% of the K assimilated is contained in vegetative
parts
• Soils require judicious and frequent application of potash fertilizers
to prevent leaching losses for better crop production..
• There is a need to consider K fixing capacity of soils, soil texture, soil
type and other factors for giving potassium recommendation to
crops.
• Continuous cropping without manures and fertilizers devoid of K
results in imbalanced fertilization by reducing availability of K. So,
use of chemical fertilizers along with organic manures improves the
availability of K to plants which increases yields.