dS/m, which agreed well with the agricultural norms (Choi et al. 2010). Furthermore,
the EBS process may increase the phosphorus content in the soil treated by bacterial
cells. The efficiency of plant germination in treated soil (87.5%) was better than in
untreated soil (25%). Hence, this electro-bio-stimulation technique can improve the
fertility of the soil.
5.2.3 Nitrate and Phosphate
Nitrate pollution has been a crucial environmental issue throughout the world since
the 1970s, causing serious environmental problem such as the eutrophication of
rivers, stomach cancer, cytogenetic defects, and birth defects. The international
drinking water quality standards recommended nitrate in the range of 50–100 mg/l
as an acceptable level. Synthetic fertilizers can improve food production in a short
period of time, so many farmers apply this fertilizer for higher productivity. However, the addition of excess fertilizer saturates the soil with salts, particularly nitrates.
Fig. 8.5 Measurement of COD content during EBS process: (a) top layer soil section (0 to 10 cm);
(b) middle layer soil section (10 to 20 cm); (c) bottom layer soil section (20 to 30 cm) (personal
observation)
Fig. 8.6 Measurement of conductivity during EBS process: (a) top layer soil section (0 to 10 cm);
(b) middle layer soil section (10 to 20 cm); (c) bottom layer soil section (20 to 30 cm) (personal
observation)
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S. Annamalai and M. Sundaram