# Which is not a positive soil pollution:-

$\begin{array}{1 1}(a)\;\text{More use of biofertilizers}\\(b)\;\text{Land filling by wastes}\\(c)\;\text{Deforestation}\\(d)\;\text{Dumping of nuclear waste}\end{array}$

Positive soil pollution refers to reduction in soil productivity due to the addition of undesirable substance in the soil. The major cause of positive soil pollution are fertilizers, mine dust, industrial waste , use of fertilizers, pesticides and weedicides. In the above options, deforestation does not add any unwanted materials to the soil. Hence is not a positive soil pollution.
Hence (c) is the correct answer.
edited Nov 29, 2017