Name two nutrients in which alluvial soil is deficient. Briefly write how the fertility of soil affects distribution of population?

Alluvial soil is deficient in organic and nitrogenous materials. Fertility of the soil affects the population in distribution. For example :
(i) Alluvial soil of the northern plains supports high density of population.
(ii) Areas of mountain soil and desert soil like Jammu and Kashmir and Rajasthan are sparsely populated.