Question

why can most plants not grow well in clayey and sandy soil

Answer 1

They do not grow in clayey soil due to its high moisture holding capacity while sandy soil is dry and plants need neither more nor less water

Answer 2

Plants cannot grow well in high or low amount of water.

Clayey soil has more water holding capacity and sandy soil is very dry which does not good water holding capacity.

Thats why plants cant grow in both types of soil.