Question

Phosphate pollution is caused by
(a) sewage and agricultural fertilizers
(b) weathering of phosphate rocks only
(c) agricultural fertilizers only
(d) phosphate rocks and sewage

Answer 1

the answer is option a) sewage nd agri. fertilizers

Studies were conducted to determine the use of an organic residue (sewage sludge compost) for four years (1996-1999), to study effects of sewage compost on crop yield and chemical properties of soil under field condition. Productivity studies showed that the greatest growth is obtained in mixed II treatment (12000 kg/ha sewage sludge compost plus 350 kg/ha urea) with 20 % more than mineral fertilization, followed by mixed 1 (8000 kg/ha sewage sludge compost plus 350 kg/ha urea) with 10 % more than mineral fertilization. No toxic effects arising from the heavy metals in the plant were observed.

Answer 2

sewage and agricultural fertilizers