http://www.hindunet.org/saraswati/megalith/munda01.htm
The cultivation of rice is an autochthonous activity in Bha_rata and
China and many regions of South and South-east Asia. The words
related to grains and fruits which are unique to the region are
possible sources for determining the nature of 'borrowings' from
Munda into Sanskrit and other Indo-Aryan languages.
The URL provides some leads in this direction indicating the etyma of
Munda justifying a hypothesis that organized farming pre-dated the
Sarasvati Sindhu Civilization and the etyma were rapidly absorbed
into almost all the language families of the country. Call it
language 'X'.
A corollary hypothesis: IE language spread eastward should have pre-
dated organized farming.
There are some questions raised on the limitations of IE linguistics
in the most recent book on the subject, just released. Edwin Bryant's
The quest for the origins of Vedic Culture which I have just finished
reading.
IE linguists will have to answer the questions.