Assertion : Soil particles, particularly clay and organic matter in...

Assertion : Soil particles, particularly clay and organic matter in soil, contain negative charges that attract positively-charged ions such as $\mathrm{Ca}^{++}$, $\mathrm{K}^{+}$and $\mathrm{Mg}^{++}$. Reason : Essential elements derived from soil are termed as mineral elements while those derived from air or water are known as nonmineral elements.