can non himachali buy agricultural land in himachal if no why ?

Answer 1

No he cannot.

Plenty of reasons for that.
1> The people in Himachal themselves depend upon the cultivation of the land. Allowing outsiders to run agricultural business over there would impact their social life.
2> Himachal is one of the few places in India where the natural serenity is still maintained. The local people over there have developed a perfect harmony with the nature and dwell with a culture that doesn't harm the nature. A person from outside the state won't be able to follow it.
3> Most of the state revenues of himachal pradesh is from tourism. Once the ourtsiders are allowed to reside into the state, the revenue generated by tourism would rapidly come down bringing the state into a financial crisis.
4> Antoer fact that needs to be considered is that there are few cities in Himachal where outsiders dwell. Cities like Kullu, Shimla, etc. When compared to other places in himachal, these places have lost there cultural essence by a slightly higher rate.

Considering all these facts, the authorities decided to uplift the local people in the state before anyone from outside the state comes in and develops. Or it would be like mumbai, where the outsiders have developed like hell but the progress of local people is still quite slow...

:-)

Answer 2

In all places mainly inhabited by tribal people, like, Arunachal Pradesh, Nagaland, Himachal Pradesh etc, law prohibits from the non locals acquiring lands and cultivating them. This is to protect the innocent tribal people being exploited by the people from the main land.
Even then some people circumvent the rule by keeping the property in the name of tribal people but enjoying the fruits by paying small sums to the innocent people.