Why is pulling the lawn roller is preferred than pushing the lawn roller ?

Pulling is easier than pushing :
i) Pulling : Roller of mass 'm' is kept on a rough horizontal surface.
ii) The weight 'mg' is acting vertically downwards. The normal reaction acts vertically upwards.
iii) Let 'F' be the pulling force acting on the roller towards right.
iv) The horizontal component 'F cos$\mathrm{\theta }$' moves the body.
v) The vertical component 'F sin$\mathrm{\theta }$ ' acts upwards. Since there is no vertical motion,
Total upward force = Total downward force
N + F sin$\mathrm{\theta }$ = mg
$\Rightarrow \mathrm{N}=\mathrm{mg}--\mathrm{Fsin}\mathrm{\theta }$
The frictional force 'f' acts towards left
$\begin{array}{l}\mathrm{f}=\mathrm{\mu N}\\ \mathrm{f}=\mathrm{\mu }[\mathrm{mg}-\mathrm{Fsin}\mathrm{\theta }]\end{array}$
 

i) Pushing : A lawn roller of mass 'm' is kept on a rough horizontal surface.
ii) The weight 'mg' is acting vertically downwards.
iii) The Normal reaction 'N' acts upwards.
iv) Let 'F' be the external force acting on roller towards right at an angle ' $\mathrm{\theta }$ ' to horizontal.
v) Horizontal component 'F cos$\mathrm{\theta }$ ' moves the body.
v) Vertical component 'F sin$\mathrm{\theta }$ ' acts vertically downwards.
Total upward force = Total downward force

$\mathrm{N}=\mathrm{Fsin}\mathrm{\theta }+\mathrm{mg}$
The frictional force 'f' acting towards left is $\mathrm{f}=\mathrm{\mu N}=\mathrm{\mu }[\mathrm{Fsin}\mathrm{\theta }+\mathrm{mg}]$
clearly, the frictional force acting while pushing is more than frictional force acting while pulling
Thus, pulling is easier than pushing.