The second lab managers’ meeting of the South-East Asia Laboratory NETwork (SEALNET) took place on 19 - 23 November 2018 in ICAR-IISS (Indian Institute of Soil Science), Bhopal, India. T Satyanarayana, PhD Director, South Asia Program, International Plant Nutrition Institute (IPNI) (1st Day)

1. Potassium in soil and plant:
analytical and management issues
T. Satyanarayana, Ph. D
Director, South Asia Program
2nd Lab Managers Meeting cum Workshop of the South-East Asia Laboratory
Network (SEALNET), ICAR-IISS, Bhopal, 19-23 November , 2018.

2. • IPNI is a not-for-profit,
scientific organization
- established in 2007 from
the Potash & Phosphate
Institute (PPI)
• We provide a scientific voice
for the world’s fertilizer
industry; independent, but
scientifically credible
The mission of IPNI is to
develop and promote
scientific information
about the responsible
management of plant
nutrition for the benefit of
the human family.

3. Intervention Themes of IPNI
• 4R Nutrient Stewardship must become globally adopted
as the scientific basis for sustainability
• Nutrient education is inadequate for current and future
agronomists
• Better fertilizer recommendations are needed to
boost productivity, economic returns and
environmental stewardship
• Yield gaps must be identified and closed to provide a
sustainable food supply
• Agricultural sustainability is only maintained by proper
nutrient management

4. Click to edit Master title style
4R Nutrient Stewardship  applying the
right nutrient source, at the right rate, right
time, and right place  is an essential tool in
the development of sustainable agricultural
systems.

5. Potassium Rate Recommendation:
General Equation
FK = Recommended rate of K
UK = Total K uptake needed to attain the climatic
and genetic yield potential
IKS = Indigenous (non-fertilizer) K supply
REK = Potassium recovery efficiency, or the fraction
of applied K taken up by the plant
(UK - IKS)
REK
Where:
Dobermann, A. and K.G. Cassman. 2002. Plant and Soil 247:153-175.
FK =

6. The K2O balance (K applied as fertilizer & Manure-Crop Removal) in (a) 2007 & (b) 2011
(Dutta et al., 2013)

7. Cropwise Net K balance (kg/ha) – 2015-16
Crop K Consumption K Uptake K Balance
Food grains 8.5 48.2 -39.7
Cereals 9.2 55.1 -45.9
Oilseeds 5.6 26.2 -20.6
Pulses 4.0 18.7 -14.7
Fiber 11.1 37.1 -26.0
Sugarcane 35.5 156.7 -121.2
Fruits 29.3 100.2 -70.9
Vegetables 26.3 55.0 -28.7
Plantation 25.1 83.5 -58.4
Spices 16.9 46.0 -29.1
Plantation 25.1 90.0 -64.9
All India 9.6 51.8 -42.2
Source : Tewatia et al. (2017)

8. Potassium use in Indian Agriculture
Year K Consumption NPK
ratio
Mt kg/ha
1965-66 0.08 0.5 7.4:1.7:1
1980-81 0.6 3.6 5.9:1.9:1
1990-91 1.3 7.2 6.0:2.4:1
1992-93 0.9 4.8 9.5:3.2:1
1999-00 1.7 8.9 6.9:2.9:1
2009-10 3.6 19.2 4.3:2.0:1
2010-11 3.5 17.8 4.7:2.3:1
2013-14 2.1 10.8 8.0:2.7:1
2015-16 2.4 12.4 7.2:2.9:1
Source: FAI statistics, 2017

9. Fertilizer use by crops
Crop
Consumption (kg/ha) NPK use
ratioN P K Total
Pulses 52.9 23.3 5.7 81.8 9.3:4.1:1
Foodgrains 82.6 36.1 12.1 130.9 6.8:3.0:1
Oilseeds 53.6 31.1 8.0 92.6 6.7:3.9:1
Sugarcane 174.7 94.2 50.7 319.5 3.4:1.9:1
Cotton 100.1 38.1 15.2 153.4 6.6:2.5:1
Fruits 81.6 54.5 41.8 177.9 2.0:1.3:1
Vegetables 95.6 64.5 37.6 197.7 2.5:1.7:1
Tea 70.3 21.0 27.8 119.2 2.5:0.8:1
Coffee 111.8 72.5 65.6 249.9 1.7:1.1:1

10. Potassium use by farm size
0
5
10
15
20
25
Marginal Small Semi-
Medium
Medium Large
21.2
15.7
11.7
8.2
5.3
KUse(Kg/ha)
All India Report on Input Survey, 2011-12

11. Plant available Potassium Status (average) in eight districts of
different agro-climatic zones of India derived from Soil Health
Card (in parenthesis percentage of total no. of sample)
District, State Very* High High
(Ave.)
Medium
(Ave.)
Low
(Ave.)
Very Low
(Ave.)
Ahmednagar, Maharastra
(n = 2,24,836)
749
(23%)
405
(53%)
205
(20%)
96
(4%)
33
(1%)
Bhopal, Madhya Pradesh
(n = 15,120)
723
(3%)
368
(32%)
206
(55%)
107
(8%)
21
(2%)
Burdwan, West Bengal
(n = 899)
830
(9%)
387
(15%)
185
(32%)
86
(23%)
38
(21%)
Guntur, Andhra Pradesh
(n = 98,504)
750
(29%)
442
(41%)
209
(26%)
93
(3%)
28
(1%)
Karnal, Haryana
(n = 44,418)
1176
(3%)
375
(8%)
180
(38%)
88
(25%)
36
(24%)
Ludhiana, Punjab
(n = 822)
0
(0%)
0
(0%)
0
(0%)
89
(100%)
0
(0%)
Mayurbhanj, Orissa
(n = 21,146)
664
(4%)
371
(11%)
182
(47%)
92
(26%)
48
(12%)
Meerut, Uttar Pradesh
(n = 31,032)
2030
(0.1%)
350
(1.9%)
198
(79%)
94
(16%)
33
(4%)
Patra, Dutta, Dey, Majumdar and Sanyal, 2017

12. 2013-14 2014-15 2015-16
Properties Range Mean Range Mean Range Mean
pH 7.9- 8.6 8.17 7.83- 8.41 8.13 8.1- 8.8 8.36
EC 0.12- 0.43 0.26 0.17- 0.39 0.26 0.20-0.32 0.25
OC 2.2- 7.9 2.62 3.6- 7.8 5.77 3.4-7.6 5.73
Avail. K2O 353.0- 593.0 473.4 367.2-633.2 460.2 324.8- 492.8 398.8
Cotton Omission Plot Study at Vertisol
0
10
20
30
40
50
60
70
80
90
100
T1 (-N) T2 (-P) T3 (-K) T4 (NPK)
Total K uptake (kg ha-1)
0
5
10
15
20
25
30
T1 (-N) T2 (-P) T3 (-K) T4 (NPK)
Seed cotton yield (q ha-1)
13%

13. Common Observations
• Black soils with high Ex. K still responds to K
fertilizer application; K omission significantly
reduces yield
• Illitic soils with low Ex. K often do not respond
to K application
• Soils with low Ex. K do not respond to low
application of K but start responding at higher
K application rates

14. Soil test K was not as predictive of crop
response as was expected
Excerpted from the 2015 IPNI Interpretive Summary:
http://research.ipni.net/project/IPNI-2014-USA-ND17
The surprise within the study so far is that using the present K soil
testing procedure, K response was accurately
predicted only half the time. There have been very low-
testing sites (80 ppm K) with no yield response to
added K; and conversely, high testing (170 ppm) sites
where substantial yield increases were obtained by
applying K fertilizer. As part of the study, the field-moist K test , as
developed by Iowa State University, was used to assess soil K availability, but
unfortunately it has been similarly unpredictive. We also tested the proposed
CEC base saturation-based K test and found it the worst predictor of any
testing procedure we have investigated ………………………….

15. Soil mineralogy was impacting crop
response to K fertilizer
Excerpted from the 2016 IPNI Interpretive Summary:
http://research.ipni.net/project/IPNI-2014-USA-ND17

16. Soil testing has been the classical approach of K determination

17. What a Standard Potassium
Soil Test Measures???

22. Illite and smectite differ in the
exchangeability of interlayer cations
Illite Smectite
Dzene, L. et al. 2017. Journal of Physical Chemistry C 121:23422-23435
Lammers, L.N. et al. 2017. Journal of Colloid and Interface Science 490:608-620

33. An explanation for the importance of
smectite:illite in K recommendations
• The critical soil test K level is lower in illitic soils
– A significant portion of the K in illite interlayers is plant-available
– Little of the K in illite interlayers is detectable by soil tests that use
ion exchange to measure K
• The critical soil test K level is higher in smectitic soils
– A significant portion of the K in smectite interlayers is plant-
available and is measured by soil tests that use ion exchange
– Smectites can fix K, especially under dry conditions
• When crop responses on illitic and smectitic soils are
averaged together, the critical level is wrong for both
– It is too high for illitic soils
– It is too low for smectitic soils

34. Desired outcome:
Knowing when a potassium
fertilizer application will be a
needed intervention to
improve economics of
production and soil health

35. IPNI researched and presented possibilities for
the importance of smectite:illite

36. The possible explanation for the importance of
smectite:illite was published
After hearing the IPNI
presentation at the
Great Plains Soil
Fertility Conference,
Dr. Franzen asked if
IPNI could provide
input into a new
Extension publication

38. How do we integrate our mineralogy knowledge
in a K recommendation system?????
Economic Consideration vs Soil K fertility

39. https://www.ndsu.edu/pubweb/soils/corn_k/

40. Frontiers in Potassium Science Workshop
• network of innovative
scientists to advance the
science of soil K evaluation
• describe and communicate
the key issues in evaluating
soil K fertility
• to develop a roadmap that
guides future efforts to
advance the science of soil K
evaluation
26-30 January, 2015 in Hawaii
http://www.isspa2015.com/

41. Creating a scientific discussion group in
the U.S.
Dr. Katie Lewis is
new to potassium
research and asked
if IPNI could
connect her to other
K scientists.
IPNI has organized
a group of K
scientists who are
willing to have
regular, virtual
meetings.

42. Frontiers of potassium science conference
• Held in Rome, Italy during January 25-27, 2017
• Brought together nearly 130 scientists and agronomists
from 37 countries
• Shared key ideas for making much needed changes to
potassium soil fertility assessments, fertilization
recommendations, and educational efforts.
• The conference was organized around the Global 4R
Nutrient Stewardship Framework
– applying the right potassium source, at the right rate, at the right
time, and in the right place
• https://conference.ipni.net/conference/kfrontiers/kfrontiers
2017.nsf/info/article/KFRONTIERS2017-10

43. International Conference on "Advances in
Potassium Research for Efficient Soil and Crop
Management"

44. Session at Clay Mineral Society of India
• Soil mineralogy and potassium inputs: the
interrelations was the identified theme
– Differential crop responses under different soil mineralogical
make-up
– Matrices related to K balance
– Improving K fertilizer recommendations

45. http://www.ipni.net
E-mail: tsatya@ipni.net
Thanks for your attention……