Kalra et al. (1998) also observed that grain yield wheat 
increased with fly ash addition up to 20 t/ha and declined 
thereafter upto 50 t/ha. Under paddy wheat rotation grain 
yield paddy increased significantly over control with fly 
ash application up to 20 t/ha and thereafter its yield 
IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002 
declined (Table 4). A maximum response of 4.5 q/ha in 
grain yield of paddy was observed when fly ash was 
applied @ 10 t/ha and a response of 2.3 q/ha was 
observed with 20 t/ha. 
Table 4 Effect of fly ash on grain yield (q/ha)of paddy and wheat 
  
  
  
   
   
   
   
  
Rate of fly ash (t/ha) Paddy Wheat 
0 63.0 47.0 
10 67.5 47.2 
20 65.3 47.9 
40 61.2 47.6 
CD (5%) spa. NS 
  
  
   
   
  
  
   
   
  
   
  
But no residual effect on grain yield of wheat was 
observed. Kansal et al (1995). also observed a significant 
response of fly ash application to rice in rice- wheat 
Soil health and crop quality 
Soil pH, electrical conductivity, organic carbon and bulk 
density were not appreciably influenced by fly ash 
additions under different crop rotations during the study 
period (Data not shown). Similarly, the content of heavy 
and potentially toxic metals like A], Cd, Cr, Ni and Pb 
rotation. Similar were the observations of others (Singh 
and Mahatim 1986 ; Arvind Kumar et al 1998; Sikka and 
Kansal 1994). 
(Table 5) in soil was not adversely affected due to fly ash 
application expect that of Hg and that too at the highest 
level of its application (40 t/ha). 
Table 5 Effect of fly ash on soil health under paddy- wheat rotation 
  
    
  
  
  
   
   
    
   
Rate of fly A] Cd Hg CT Ni Pb 
ash(t/ha) 
(ppm) 
0 2.13 0.03 ND 0.75 0.20 2:20 
10 1.91 0.02 ND 0.97 0.20 1.79 
20 2.05 0.01 ND 0.64 0.14 0.96 
40 1.24 0.01 5.0 0.86 0.10 1.24 
  
  
   
  
  
   
   
   
   
   
   
The analysis of rice, wheat and maize grain also revealed 
that their total concentration of Cd, Cr, Ni and Pb 
remained well within the permissible limits of 5-30, 5- 
30, 10-100 and 30-300 ppm, respectively as given by 
Element/Fly ash Paddy 
t/ha 0 40 
Al 36.9 36.9 
Cd 
Alloway (1990). But like that of soil the content of Hg 
was also high in grain of these crops. 
Table 6 Effect of fly ash on chemical composition (ppm) of grains 
Maize Wheat 
0 40 0 12 
23.2 54.0 27:4 229.8 
  
  
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