IAPRS & SIS, Vol.34, Part 7, "Resource and Environmental Monitoring", Hyderabad, India, 2002
AGRICULTURAL APPLICATION OF COAL COMBUSTION RESIDUE FOR
EFFICIENT ENVIRONMENTAL MANAGEMENT
D.S. Benipal, B.D.Kansal J.S. Manchanda and C.L. Arora
Department of Soils
Punjab Agricultural University Ludhiana (India)
email: dsbenipal ?9 yahoo.com
KEY WORDS: Fly ash, Environment, Coal combustion, Agriculture
ABSTRACT :
The fly ash contains many elements including essential nutrients viz. Nitrogen, Phosphorus, Potassium, Calcium,
Magnesium, Sulphur, Iron etc. So it can serve as a source of essential nutrients for plants. However there is a
possibility of toxicity of heavy metals in crops because fly ash contains good amounts of such metals like Arsenic,
Selenium, Chromium, Nickel and Lead It is also found to increase the water holding capacity of coarse textured soils as
the saturation moisture percentage of fly ash is about 2096 more than that of normal soils. Experiments were conducted
at farmers' field in submontane tract of Punjab (India) to study the effect of fly ash on crops in different crop rotations.
The pH, EC, OC and bulk density of soils used in this investigation varied from 8.3 to 8.5, 0.16 to 0.24 dSm'!, 0.59 to
0.63% and 1.19 to 1.40 g cm? respectively. The soils were sandy loam in texture. Fly ash collected from Thermal
Power Plant, Ropar, Punjab (India) was applied at different rates and the crops were grown to maturity. Basal doses of
N, P, K were applied to crops and crops were raised as per recommended practices. Soil and plant samples were
collected and analyzed for essential as well as non-essential elements with the help of ICAP. Seed yield of sunflower
had increased significantly with the application of 20 t/ha of fly ash. Grain yield of wheat increased by 2.8 q/ha when
fly ash was added @ 8t/ha, but like that of sunflower-maize cropping sequence, the yield of subsequent (following)
maize was not influenced by fly ash application showing no residual effect of fly ash. Grain yield of paddy increased
significantly when fly ash was applied @ 10t/ha as compared to control
INTRODUCTION
Solid waste produced by burning of coal in Thermal
Power Plants is popularly known as fly ash, which
constitutes about 80 percent of the total residues,
produced in coal based power plants. In India there are
about 75 Thermal Power Plants and about 100 million
tones of fly ash was produced during the year 2000. By
the end of 2007 its production is further expected to
increase to the tune of 175 million tones per annum. A
major problem being faced these power plants world over
is the safe disposal of this byproduct. In India this
problem is further aggravated by low calorific value
(3000-4000 kcal/g) and high ash content (40-50%) of
Indian Coal. At present only about 3-4% of total fly ash
METHODS AND MATERIALS
Field experiments were conducted at cultivators’ field in
submontane tract of Punjab (India) to study the effect of
fly ash on sandy loam soils under sunflower-maize and
wheat-maize rotations during 1998-99 and paddy-wheat
rotation during 1999-2000. The pH, electrical
conductivity, organic carbon and bulk density of soils
used in this investigation varied from 8.3 to 8.5, 0.16 to
0.24 dS'm, 0.59 to 0.63% and 1.19 to 1.40 g cm?
respectively. Fly ash collected from the dumping sites of
a Thermal Power Plant, Ropar, Punjab (India) was
produced is being recycled through manufacture of
cement, bricks and road construction. A bulk of fly ash is
being disposed off on to the nearby agricultural lands
thereby converting them into wastelands. Chemically, fly
ash is a ferroalumino silicate material having high water
holding capacity, low bulk density and is a rich source of
essential plant nutrients besides some other trace metals.
These characteristics of fly ash favour for its use in
agriculture. Thus, to explore the possibility of its use in
agriculture an attempt was made to study the effect of fly
ash on i) crop yield ii) quality of crops and iii) soil health
in sunflower-maize, wheat-maize and paddy-wheat
rotation.
applied € 0,10,20 and. 40 t/ha to in sunflower —maize
and paddy-wheat rotations and @ 0,4,8, and 12 t/ha in
wheat —maize rotation at the time of sowing and was
thoroughly mixed in the plough layer. Average Chemical
composition of fly ash used in this investigation is given
in Table 1. Fly ash was applied only to the first crop in
rotation and its residual effect was studied on the
succeeding crops. Basal doses of N, P, K were applied to
all the crops and recommended packages of practices
were followed to raise these crops to maturity.
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