i am expert at soil scientist

2. Management of
Problematic soil
PRESENTATION
ON
Presented by
Ram Prasad Pendro

3.  Problematic soils are classified into 2 major groups:
 Acid soils
 Salt affected soils (Saline and Alkali soils & saline-
alkaline soils)
Other type of problematic soil is
 Calcareous soil
• Acid soils occur in those areas where rainfall is higher,
i.e precipitation > evapo-transpiration
• Salt affected soils occur in arid and semi arid regions where,
precipitation < evapo-transpiration
• Calcareous soils occur in semi-arid region which contains
parent material like CaCO3 (pedogenic)
• In India Acid soil covers 49.0 million ha, whereas, salt
affected soil covers 8.0 m.ha

4. • Acid soils are characteristically low in pH
(<6.0).
• Predominance of H+ and Al3+ cause acidity
resulting in deficiency of P, K, Ca, Mg , Mo
and B.

5. Acid soil with < 5 pH deficient in Ca, Mg & K which are leached
beyond root zone.
Occur in regions with high rainfall.
Also deficient in sulphur and boron.
Excessive amount of soluble Al, Fe and Mn which are harmful to
plant growth.
Also contain toxic amount of copper and zinc.
Deficient in available P as precipated in insoluble hydroxyl
phosphate.
Bacteria and actinomycetes will be ineffective and fungi
dominate.
Suitable crops : acedophytes – potato, rice, tea, coffee and cotton.

6. Figure of acid soil

7. • Properties of acid soil
 Low CEC
 Intermediate texture (Sandy loam to Loam)
Low organic matter content (except hilly
region and forest soils)
Low P content but N is variable
High amount of Fe and Al in soil solution.

8. .
Descriptive terms pH range Buffering mechanism
Extremely acid <4.5 Iron range (pH 2.4–3.8)
Very strongly acid 4.5–5.0 Aluminum/iron range
(pH3.0–4.8)
Strongly acid 5.1–5.5 Aluminum rang(pH 3.0–4.8)
Moderately acid 5.6–6.0 Cation exchange (pH 4.2–5.0)
Slightly acid to
neutral
6.1–7.3 Silicate buffers
(all pH values typically >5)
Slightly alkaline 7.4–7.8 Carbonate (pH 6.5–8.3)

9. SOURCE OF ACIDITY
1. Leaching of basic cations due to heavy rainfalls
1. Acidic parent material
2. Acid forming fertilizers and soluble salts
3. Humas and other organic acids
4. Aluminosilicate minerals
5. Carbondioxide (CO2)
6. Aluminum and Iron polymers

10. States pH<4.5 pH <5.5 pH 5.5-
6.5
Total
Anurachal Pradesh 4.78 1.74 0.27 6.79
Assam 0.02 2.31 2.33 4.66
Bihar 0.02 0.04 2.32 2.36
Chhattisgarh 0.15 6.30 4.39 10.87
Goa _ 0.11 0.19 0.30
Himachal pradesh _ 0.16 1.62 1.78
Jharkhand _ 1.00 5.77 6.77
Karnataka _ 0.06 3.25 3.31
Kerala 0.14 2.87 0.75 3.76
Madhya pradesh _ 1.12 10.60 11.72
Maharashtra _ 0.21 4.33 4.54
Extent of acid soils in different States in india (mha)
Source-NBSSLUP, Nagpur, 2012

11. • Problems of acid soil
• Adverse effects of Acid soils on plant growth may be due to
following reason
1. Toxicity of elements (Al, Mn, Fe)
2. Deficiency of bases (Ca+2, Mg+2)
3. Imbalance of P,S and Mo
4. Poor microbial activity
Toxic effects of Al :- Al inhibits the root growth of the plants,
interferes with the various physiological process of the plants like
cell-division, respiration and DNA synthesis; restricts the uptake
of Ca+2, P and H2O
Mn–toxicity: In soils having pH below 5.0, excess Mn
accumulates in all the tissue of the plant, the normal
metabolism of the plant is seriously affected.

12. • Fe-toxicity: iron concentration in soil increases
with the decrease in pH, increase in O.M.
content and the intensity of soil redn.
• Under waterlogged condition of rice
cultivation the soil undergoes reduction which
reduces Fe+3 iron to Fe+2 iron which is more
soluble and sometimes the concentration of Fe+2
in waterlogged rice soils becomes high and hence
toxic to rice plants. This creates what is known as
physiological diseases of rice(browning disease).

13. • 2. Deficiency of bases:
• The amount of exchangeable Ca, Mg is lower in acid soils.
Percentage base saturation is also low as the most
exchangeable sites are occupied by Al and H. Ca and Mg are
secondary essential elements as far as plant nutrients are
concerned. Plant (Leguminous plant) require high amount of
Ca and Mg. Due to lack of Ca and Mg yield will be hampered.
But Rice, wheat do not require Ca, Mg, so not seriously
affected.
• Ca, Mg improve the structure of the soils and so their
deficiency will give rise to poor structure of the soil and thus
they inhibit proper aeration.
• Microbial activities are also decreased due to the
insufficiency of bases. So, mineralisation will be adversely
affected .

14. 3. Imbalance of Nutrient elements:
a) Phosphorus: i) P in soil is precipitated due to
formation of AlPO4 and FePO4. In acid soil Al and Fe
concn is high. So availability of P in acid soil is very
low.
ii) Plant generally take up P from soil in the form of
H2PO4
- and HPO4
-2. Chemical adsorption on the surface
of the colloidal material and soil dominated with
kaolinite clay mineral adsorbs more P. Therefore, P is
not released from the surface and P availability will be
low.

15. b) Sulphur: most of the S in soils present in organic form.
These organic S are mineralised by some soil microbes.
But in acid condition, they can’t function well to mineralise
the S. these micro org. can’t grow well in low pH. Unless
these S are changed to inorganic form, plant can’t absorbs
S as nutrients.
c) Molybdenum (Mo): generally micro nutrients are more
soluble in acid soil but Mo is the exception. Mo is less
soluble in low pH and thus becomes less available to
the plants. In acidic condition it produces insoluble
molybdates. Lack of Mo reduces N-fixation.
4. Poor microbial activity: most of the microbes prefer
neutral pH. So in acid condition, their activity will be
affected.

16. Effect of pH on the
availability of
nutrients important in
plant growth and of
microorganisms. As the
band for a particular
nutrient or microbe
widens, the availability of
the nutrient or
activity of the microbes is
greater. For example,
with K the greatest
availability is from pH ~6–
9.
From Brady (1984),

17. Root system affected Poor maize crop
by acidity in an….. acid field
Source : http//www.rag.org.au/phildickiestories

18. Management of acid soils
• How to overcome the deleterious effect
i) Agronomic approach –grow acid tolerant crops
ii) Chemical approach- use liming material to increase
the soil pH

19. • Some important crop species, pasture species, and
plantation crops tolerant to soil acidity in the tropics

20. LIMING MATERIAL
 Calcic limestone (CaCO3) ground fine
 Dolomitic limestone:. CaMg(CO3)2
 Quicklime (CaO): burned limestone (lost a CO2)
 Hydrated quicklime (Ca(OH)2)): quicklime hydrated
with water
 Marl: CaCO3 from freshwater ponds.
 Chalk: CaCO3 from ocean deposits.
 Blast furnace slag (CaSiO3, CaSiO4). Also contains P.
 woodash, by product of paper mills etc.

21. • 1. CO2 + H2O  H2CO3
• 2. H2CO3 + CaCO3 (insoluble)  Ca(HCO3)2 Soluble
• 3. Ca(HCO3)2  Ca+2
+ 2 HCO3
-
H
4. (Clay) + Ca+2 Ca----(Clay) + 2H+
H
• 5. H+ + HCO3
-
H2CO3
H2CO3+ CaCO3 (insoluble)  Ca(HCO3)2

22. LIME REQUIREMENT(LR)-
The lime requirement of an acid soil is the amount of
a liming material that must be added to raise the soil
pH to a desired level. usually in the range of 6.0 to
7.0)
The lime requirement ranges from 3.5 to 15 t/ha

23. Lime Requirement of an acid soil
pH of soil
buffer suspension
(field soil sample)
Lime required to bring the soil to indicated pH
(in tones per acre of pure calcium carbonate i.e.CaCO3)
pH 6.0 pH 6.4 pH 6.8
6.7
6.6
6.5
6.4
6.3
6.2
6.1
6.0
5.9
5.8
5.7
5.6
5.5
5.4
5.3
5.2
5.1
5.0
4.9
4.8
1.0
1.4
1.8
2.3
2.7
3.1
3.5
3.9
4.4
4.8
5.2
5.6
6.0
6.5
6.9
7.4
7.8
8.2
8.6
9.1
1.2
1.7
2.2
2.7
3.2
3.7
4.2
4.7
5.2
5.7
6.2
6.7
7.2
7.7
8.2
8.4
9 .1
9.6
10.1
10.6
1.4
1.9
2.5
3.1
3.7
4.2
4.8
5.4
6.0
6.5
7.1
7.7
8.3
8.9
9.4
10.0
10.6
11.2
11.8
12.4
Source: Introductory of soil science, by Dr. Vinay Singh, page no.236

24. Soil pH Lime Requirement in
Kg/ha
Sandy loam Loam Clay loam
5.0 1262 1892 2944
5.2 1093 1639 2551
5.4 925 1387 2159
5.6 757 1135 1766
5.8 589 883 1374
6.0 421 630 981
Ready rekoner
Source : http/www.scribd.com

26. Problem Soils in South and Southeast Asia (Adapted from
Ponnamperuma and Bandyopadhya 1980)
Problem Soils in South and Southeast Asia (Adapted from

27. Saline soils
 Saline soils are characterised by higher
amount of water soluble salt, due to which
the crop growth is affected.
 For these soils with electrical conductivity of
more than 4 dS m¯¹.

29. Figure of saline soil

30. Management of Saline soil
(A)Mechanical method
 Flooding and leaching down of the soluble
salts
 Scraping of the surface soils

31. (B)Cultural method
 Providing proper drainage
 Use of salt free irrigation water
 Proper use of irrigation water
 Plating or sowing of seed in the furrow
 Use of acidic fertilizer ex. Ammonium sulphate
 Ploughing and livelling of the land
 Use of organic manures
 Retardation of water evaporation from soil surface
 lateral and main drainage channels of 60 cm deep and 45 cm
wide and leaching of salts could reclaim the soils.

32. • Growing of the salt tolerance crops:
• High salt tolerance crop: Barley, Sugar beet, Para grass etc.
• Moderately salt tolerant crops: Wheat, rice, maize, sorghum
• Low salt tolerance crops: Beans, radish, white clover etc.
• Sensitive crops: Tomato, potato, onion, carrot etc.

33. (C)Biological management
 Use of organic materials
 Application of fym
 Application of farm yard manure at 5 t ha-1 at 10 -
15 days before transplanting in the case of paddy
crop and before sowing in the case of garden land
crops can alleviate the problems of salinity.
 Pressmud
 Incorporation of crop residues
 Use of green manuring crops

34. Alkaline soils
The ESP > 15% and the pH between 8.5
-10
Leaching of saline – alkali soil in the
absence of Gypsum in soil leads to
formation of alkali soil
NaOH formed due to hydrolysis dissolves
the OM present in the soil and dispersed
and is deposited on the surface by
evaporation causing darkening of the soil
called as black alkali

35. Figure of alkaline soil

36. Area under soil salinity and alkalinity in the world
continent salinity alkalinity Total (m ha)
North america 6.2 9.6 15.8
Maxico and central
america
1.9 1.9
South america 69.4 59.6 129.0
europe - 50.8 50.8
africa 53.5 26.9 80.4
South asia 83.3 1.8 85.1
North and central asia 91.6 - 211.7
South-east asia 19.9 - 19.9
australia 17.4 340.0 357.4
total 343.2 608.8 952.0
source:fao/unesco,1974soil map of the world

37. State(india) Area (thousand ha)
Andhra pradesh 394
bihar 85
goa 17
gujrat 1649
haryana 555
punjab 480
Jammu and kashmir 80
karnatka 179
kerala 45
Madhya pradesh 242
maharastra 127
orrisa 135
rajastan 1183
tamilnadu 470
Uttar pradesh 958
Andman and nicobar islands 1
delhi 0.6
pondicherry 0.3

38. management of Alkali soil
• (A)chemical method
• Gypsum: Gypsum a natural sulphate of calcium is
found in large deposit in various parts of
Rajasthan. It reacts with exchangeable Na with
getting converted into sodium sulphate. Sodium
sulphate is from the soil to reduce pH. The
addition of gypsum improves the physical
conditions of soil. Soils become flocculated and
drainage improves.
• CaSO4 + 2 Na X = Ca X + Na2SO4

39. Chemical reaction in soil
 Gypsum (CaSO4.2H2O)
Gypsum react with both Na2CO3 and the adsorbed
sodium as follows:
Na2CO3+CaSO4←CaCO3+Na2SO4↓
→
clay+CaSO4 ←Ca clay + Na2SO4↓
→

40. • Sulphur: Sulphur is a very effective chemical
amendment to replaces exchangeable Na.
Theoretically, one atom of sulphur replaces four Na
ions by calcium. But under field conditions
approximately, three exchangeable Na ions per atom
of sulphur are replaced from the soil colloids.
2S+3O2=2SO3 (by the action of sulphur oxidizing
bacteria in soil)
SO3+H2O=H2SO4
H2SO4+Na2CO3←CO2+H2O+ + Na2SO4↓

41. • Iron sulphate: Iron sulphate is sometimes used as a
chemical amendment for improving alkali soil. Iron
sulphate forms sulphuric acid, which is converted
into calcium sulphate. Calcium sulphate, thus formed
replaces exchangeable sodium as indicated by
following equations.
• FeSO4 + H2O ----- H2SO4 + FeO
• H2SO4 + CaCO3 ------- CaSO4 + H2O + CO2

42. • Blue green algae like nostoc anabaena and
scytonema are often employed in the
reclamation of alkaline soil

43. Management of waterlogged soils:
• Drainage: drainage removes excess water from the
root zone that is harmful for the plant growth. Land
can be drained by surface drainage, sub-surface
drainage and drainage good method.
• Controlled irrigation: Excess use of water in the
irrigation results in water logged area.
• To check the seepage of canal: Due to seepage land
becomes water logged

44. • Flood control measures: Construction of bund may
check water flows river of the cultivated land.
• Plantation of trees having a higher evaporation
rate: Transpiration rate of certain trees like
Eucalyptus, Acacia is very high. In transpiration
process the underground water is consumed by
trees, thus lowering the ground water table

45. • Selection of crops and their varieties:
Certain crops like paddy, water nut, jute and Sesbenia
can tolerate waterlogged conditions. In trice crop sub-
merged varies from variety to variety. Generally
lowland and deep water varieties can tolerate water
logging, but upland varieties do not have this capacity.

46. • Methods of sowing: In water logged areas,
sowing should be done on bunds or ridges. In
this method there is a scope of good aeration
near the root zone.
• Nutrient management: Low nitrogen fertility is
an important constraint in the waterlogged soil.
The predominant form of nitrogen in water
logged soils is NH4.

47. Figure of calcareous soil

48. Management of calcareous soils:
• Tillage operation: Light (Sandy) calcareous soil
develops a large number of pore spaces due to
flocculation. This type of soil has poor water holding
capacity. Therefore, such types of soils are needed
compaction by plank and roller to increase the water
holding capacity.
• Application of organic manure: When sufficient
amount of farmyard manure composts and green
manure is added, the amount of carbon dioxide and
acid increase and as a result pH of soil decreases.

49. • Use of chemical fertilizers: Availability of phosphorus
is less in calcareous soil. To increase the availability of
P, the phosphorus fertilizers should be used in the
following manner
– Phosphatic fertilizers should be used near the root
of the plant.
– Use of Phosphatic fertilizer in ball form also
increases the availability of P.
• P may be used in split form.
• Use of micronutrients: Addition of micronutrients like
Zn, Fe and Cu would be helpful in increasing the yield.