This document summarizes the role of potassium in field crops. It discusses that potassium is a primary nutrient that plays a critical role in plant growth and metabolism. It is abundant in plant tissues at 1.0%. The document then discusses various functions of potassium in plants including enzyme activation, photosynthesis, stomatal activity and water use, transportation of sugars, and starch synthesis. It also summarizes potassium deficiency symptoms in various crops like potatoes, maize and soybeans. It provides details on various potassic fertilizers and concludes with research findings on the impact of potassium levels on yield of wheat, rice, and cotton.

1. SAM HIGGINBOTTOM UNIVERSITY OF AGRICULTURE
TECHNOLOGY AND SCIENCES
Advisor:
Prof.(Dr.) JOY DAWSON
H.O.D (dept. Of Agronomy)
SHUATS, ALLHABAD
AGRN 780
MASTER’S SEMINAR
ROLE OF POTASSIUM IN FIELD CROPS
Submitted by:
SUMAN KUMAR DEY
18MSAGRO070
MSc. Ag.(Agronomy)
1st semester

2. INTRODUCTION
Potassium content in plant tissues-1.0%
Out of all crucial nutrients potassium play a critical role in plant growth and
metabolism.
 Potassium is a primary nutrient and is also the most abundant cation in plants.
 In the soil ,the principal sources of potassium are minerals such as
feldspar(particularly orthoclase) and micas which release this element in the
course of their weathering.
 20% soil in India are potassium deficient.
 “LUXURY CONSUMPTION” can be done by plants.
 Regulates ion movement( so it is called as TRAFFIC POLICEMAN of the plant).
 Reduces lodging in cereal crops.

3. FUNCTIONS OF POTASSIUM IN PLANTS
1)ENZYME ACTIVATION-
 Enzyme serve as a catalysts for chemical reactions,being utilized
but not consumed in the process.
 Potassium activates at least 60 different enzymes involved in plant
growth.
2)PHOTOSYNTHESIS:
The activation of enzymes by potassium and its involvement in
adenosine triphosphate (ATP) production is probably important in
regulating the rate of photosynthesis.
 The ATP is then further used the energy source for many other
chemical reactions.

4. 3)STOMATAL ACTIVITY(WATER USE)
 Plants depend upon potassium to regulate the opening and closing
of stomata.
 Proper functioning of stomata is essential for photosynthesis, water
and nutrient transport.
 When potassium moves into the guard cells of stomata, the cells
accumulate water and swell causing the pores to open and allowing
gases to move freely in and out.
 When water supply is short, potassium is pumped out of the guard
cells ,the pore close tightly to prevent loss of water.
 Accumulation of potassium in plant roots produces a gradient of
osmotic pressure that draws water into the roots.

5. 4)TRANSPORTATION OF SUGARS
 Sugars produced in photosynthesis must be transported through
the phloem to the other parts of the plants for utilization and
storage.
 The plants transport system uses energy in the form of ATP.
 If potassium is inadequate, less ATP is available and the transport
system breaks down..
 This causes photosynthates to build up in the leaves.
5)STARCH SYNTHESIS-
The enzyme responsible for synthesis of starch(starch synthetase) is
activated by potassium.

6. POTASSIUM DEFICIENCY SYMPTOMS IN PLANTS
 First symptoms at older leaves.
 Stunted growth
 Shortening of internodes.
 Bushy appearance.
 Chlorosis, yellowing of leaves.
 Scorching and browning of leaf tips and margins.
 Grapes- uneven ripening.

7. POTASSIUM EARLY DEFICIENCY SYMPTOMS POTASSIUM LATE DEFICIENCY
IN POTATO SYMPTOMS IN POTATO

8. POTASSIUM DEFICIENCY SYMPTOMS POTASSIUM DEFICIENCY SYMPTOMS
IN MAIZE IN SOYABEAN

9. POTASSIC FERTILISERS
1) INORGANIC POTASSIC FERTILISERS-
 Commonly used potassic fertilisers in India-
1) Muriate of potash(potassium chloride,KCL).
2)potassium sulphate.
Not produced in India(imported).
potassium salts found in France, Canada , USA.
In India, Leh (j & k),Bikaner(Rajasthan)-Not exploited for commercial use.

10. White to red crystalline kcl salt
Contains 60% K₂O.
Contains chlorine not recommended
for tobacco, potato , tomato.
Not lost by leaching.
MURIATE OF POTASH-

11. POTASSIUM SULPHATE-
1) contains 48 to 52% K₂O.
2) neutral salt.
3) soluble in water.
4) best for potato , tobacco.

12. POTASSIUM SCHOENITE-
contains 22-44% potash.
Developed by CENTRAL SALT AND
MARINE CHEMICAL RESEARCH
INSTITUTE

13. 2)ORGANIC POTASSIC FERTILISERS
WOOD ASHES.
CATTLE DUNG ASH.
TOBACCO STEMS.
BANANA LEAVES.

14. RESEARCH FINDINGS

15. Levels of
potassium(Kg/ha)
Grain yield(t/ha) Straw yield(t/ha) Total biomass yield
0 2.60 3.73 6.35
12 2.98 4.10 7.12
24 3.07 4.17 7.29
36 3.40 4.57 7.98
LSD(0.05) 0.27 0.15 0.41
TABLE:1 EFFECT OF DIFFERENT LEVELS OF POTASSIUM ON YIELD OF
WHEAT
(Singh ,2000)

16. TABLE-2 IMPACT OF SOIL POTASSIUM BUILD UP ON RICE STEM
BORERS AND GRAIN YIELD
(Sarwar , 2012)
TREATMENT
NUMBER
POTASSIUM
TREATMENTS
(Kg/Ha)
DEAD
HEART(%)
WHITE
HEADS(%)
YIELD
(Kg/Ha)
1 40kg 3.05 5.37 6376.66
2 50kg 2.64 3.58 7623.33
3 60kg 2.40 3.37 7723.33
4 control 4.33 7.12 5633.33
LSD(0.05) 0.519 0.561 219.4

17. TABLE-3 EFFECT OF FOLIAR APPLICATION OF POTASSIUM
ON COTTON YIELD
(Gormus ,2002)
TREATMENTS
K RATE(g/ha)
SEED YIELD
(Kg/ha)
LINT
(Kg/ha)
0 2793 988
319 3069 1083
638 3163 1115
957 3241 1143
LSD(P=0.05) 162 54

18. CONCLUSION:
The data available from the above research on the role of
potassium availability in the growth of plants indicates that
potassium is frequently a limiting factor for plant productivity.
Apart from physiological processes(enzyme function, internal
transport system) and ecological processes (resistance to cold,
frost, increase shelf life of fruits) potassium plays a vital role in
disease resistance and quality, yield parameters of many field
crops.

19. REFERENCES:
Sarwar, M., 2012, Effects of potassium fertilization on population build up of rice stem
borers(lepidopteron pests) and rice (Oryza sativa L.) yield. J. Cereals Oilseeds 3, 6–9.
.
Gormus, O. 2002. Effects of foliar application of potassium on cotton yield and quality in Turkey. J.
Agron.Crop Sci. 188: 382-388.
Singh, J., H.L. Sharma, and C. M. Singh. 2000. Effect of levels and phases of potassium
application on growth and yield of rice and wheat. J. Pot. Res. 16(1-4): 35-40.
Amtmann, A.; Troufflard, S.; Armengaud, P. The effect of potassium nutrition on pest
and disease resistance in plants. Physiol. Plantarum 2008, 133, 682–691.
Ashley MK Grant M and Grabov A (2006). Plant responses to potassium deficiencies: a role for
potassium transport proteins. Journal of Experimental Botany 57(2) 425–436.
McAfee J (2008). Potassium, A Key Nutrient for Plant Growth. Department of Soil and Crop
Sciences

20. THANK YOU