Science 7 - LAND and SEA BREEZE and its Characteristics
ASH MAINTENANCE
1. Use of fly ash in Forestry
Plantations & Land
Reclamation:
An overview
2. Photomicrograph made with a Scanning Electron Microscope (SEM): Fly ash particles at 2,000x magnification
3.
• More and more fly ash will
be produced annually at the
rate of 2 tonnes of fly ash
per minute at a modern 660
MW capacity generating
unit.
At present about 120 coal
based thermal power
stations in India are
producing about 220
million tones of fly ash
annually.
It is estimated that fly
ash generation may
increase to about 500
million tones by 2021-22
and 1000 mt by 31-32
Disposal of such a huge
quantity of fly ash poses
challenging problems of
land use and
environmental pollution
(50000 ha ash pond).
4. Parameters
pH
Specific gravity
Bulk density (g/cc)
Grain size distribution
Fly ash
6.0 - 10.0
1.45 - 2.25
0.85 - 1.2
silt to Silty
loam
Porosity (%)
45 – 55
Water holding capacity
25 – 40
(%)
Electrical
conductivity 0.15 – 1.10
(dS/m)
Natural Soil
4.5 – 14.0
2.55 – 2.75
1.30 – 1.80
Varies with
soil type
20 – 60
10 – 45
variable
7.
Improves soil texture and reduces bulk density.
Improves permeability and water holding capacity
Improves Improvisation and reduces crust formation.
Enhances root proliferation.
Conserves plant nutrients and water.
Reduces pest incidence.
Provides macro (K, P, Ca, Mg, S) and micro (Fe, Zn, Cu,
Mn, Mo, B) nutrients
Part substitution of gypsum (up to about 75% with fly ash
as a substitute for reclamation of in sodic – saline soils
Enhance plant productivity and crop yield
8. To demonstrate fly ash use in forestry sector especially for
raising of nursery, forestry application and restoration of
forests, IMMT, Bhubaneswar and OSFDC has
demonstrated a project during 2009-2011 at Angul and
Talcher forest circle under Forest Dept. of Orissa.
Towards this, pond ash and soil mixtures 0%, 33%, 67%
and 100% on v/v basis were filled in 2 kg black polythene
bags and trusted quality seeds have sown during Feb.March, 2009 at Angul and IMMT, Bhubaneswar.
10. 1.
Barabati in Sukinda Range:
Plant species- Teak (Approx. 80,000 )
Forest Nursery-In other demonstration at Sukinda nursery
approx. 60,000 teak saplings were planted with 50% pond ash
(v/v) with soil in poly tubes along with 20,000 control
saplings (without ash).
2.
Kiajhara in Tamka Range:
Plant species- Teak, Acacia, Radha Chura, Chhattiyan,
Karanj, Sissoo, Anwala and Bamboo (Approx. 30,000 )
Treatment details- 0, 25% and 50%(v/v) of fly ash in pits.
11.
12.
13.
14.
15. Plant
species
Teak
July 2009 (Initial height* in cm)
Control
25% FA
(No
Fly
Ash)
39.0
38.5
50% FA
39.5
Sept. 2013 (Now height* in cm)
Control
25% FA
(No Fly
Ash)
218.5
228.0
50% FA
294.0
Acacia
39.5
39.0
37.0
232.0
230.5
241.0
Radha
chura
Chhattiyan
37.5
38.0
38.0
230.0
241.0
266.0
37.0
39.5
39.5
268.0
274.0
264.0
Karanj
36.0
35.0
36.5
240.0
284.5
295.0
Shisham
39.0
40.0
39.0
247.5
256.0
274.0
Anwala
40.5
38.5
37.5
222.0
232.4
271.0
*mean of 20 replications
16. Plant
species
July 2009 (Initial girth* in cm)
Sept. 2013 (Now girth* in cm)
Control
25% FA 50% FA
(No
Fly
Ash)
Control 25% FA 50% FA
(No Fly
Ash)
Teak
3.0
3.2
3.4
27.5
35.5
42.0
Acacia
2.4
2.5
2.4
17.5
18.0
17.5
Radha
chura
Chhattiyan
3.5
3.0
3.5
35.5
42.5
46.5
3.8
3.5
3.6
28.5
32.5
36.0
Karanj
3.5
3.0
3.2
27.0
22.5
26.0
Shisham
2.6
2.5
2.8
28.5
33.0
39.5
Anwala
2.0
2.5
2.4
21.0
27.5
29.5
*mean of 20 replications
17.
Cost of transportation of ash to farmers’ fields
Lack of awareness on its beneficial use
Need to strengthen extension work for fly ash use in
agriculture/forestry
Need to increase awareness among agricultural/forest
official in the extension area
Need to increase awareness among agricultural scientists
at large and to take up location specific projects
Need to increase policy support to facilitate & promote
use of fly ash in this sector
19. Degradation type
Arable
Open forest
land M ha (<40%
canopy) M ha
Water erosion (>10 t/ha/yr)
73.27
9.30
Wind erosion (Aeolian)
12.40
-
Chemical degradation
17.45
7.23
Physical degradation
1.07
-
Total
104.19
16.53
Grand total
120.72
20.
Due to its physical and chemical properties
resembling field soils, Fly ash has potential to
reclaim such areas
Thousand of hac. of wastelands due to strip
mining of coal have been effectively
reclaimed and stabilized using fly ash at
Neyveli, MCL, Talcher, CSTPS, Chandrapur
etc.
21.
The microecology and chemistry of soil
Physical properties as WHC, BD, structure
Soil texture, aeration, percolation, water
retention capacity of soil
Enhances nutrient status by its macro and
micro nutrients (Ca, Mg, Fe, Zn, Mo, S, Se)
readily available to crops / vegetation
It’s a potential growth improver and serves as
a good fertilizer
22.
It is observed that at all levels of application, fly ash
and lime were comparable and significantly
increased the pH and availability and uptake of
phosphorus, sulphur and exchangeable potassium.
Laboratory studies have shown that alkaline fly ash
was chemically equivalent to approximately 20 % of
reagent grade CaCO3 in reducing soil pH and
supplying Ca to the plants.
Addition of large quantity of slightly acidic fly ash
may not alter the pH appreciably but can still
increase the available Ca 2+ and Mg 2+. The
neutralizing ability of fly ash also depends on its
source and extent to which it is weathered.
23.
Role of fly ash in ameliorating the bulk density and
consequently the water holding capacity / drainage
appears to have a major role in showing the positive
ameliorative effects. It may have a major role in the
post gypsum treatment level to improve the physical
structure which results in higher crop yield right in
the first year and there after.
In such a situation fly ash use is also expected to
reduce fluoride contamination in the ground water as
it is an effective adsorbent of fluoride. Thus, an
important environmental problem can be also
addressed through fly ash application.
24.
Fly ash has been used for the neutralization of acidic
mine spoils and restoration of nutrient balance in
alkaline wastelands.
The quantity of fly ash required to reclaim such areas
depends upon the pH of fly ash, state of weathering
and pH of the land to be reclaimed.
Fly ash acts as alternative to lime for reclaiming the
acidic mine spoils. Efficacy of fly ash for treating
acidic coal mine spoils was evidenced by the results
of a pot culture experiment using Sudan grass
(Sorghum sudanens) and Oats (Avena sativa) as
indicator crops.
25.
Fly ash can be safely applied in agriculture/ forestry
sectors and wasteland management as soil modifier/
conditioner and as a source of liming agent/ essential
plant nutrient on sustainable basis.
Crops grown on fly ash amended soil safe for human
consumption.
The OB dumps/ abandoned ash ponds successfully
reclaimed through plantation of suitable species and
various amendments.
Need for more awareness on beneficial use of fly ash.
26. Fly ash application in red and black soils resulted in
decrease in the bulk density measured three years after
application in field.
•Fly ash application upto 100 t/ha in red and black soils of
the experiment did not show any perceptible change in the
radioactivity levels.
• Concentrations of heavy metals, did not cross their toxicity
limits on application of fly ash; Pb, mercury was below the
detection limit
• FA significantly affected the green forage yield of
sorghum and cowpea in both the soil types. The increase in
forage yield due to fly ash use was more pronounced at
50t/ha.
•
