Pine needles and roots acidify the soil under the tree. As big as that tree is..the soil has been acidic for decades. Pine roots are shallow and absorb all the available moisture. The shade from the tree is an issue as well.
I wouldnt waste the time trying...landscape the area with a circle of stone and bark mulch and throw a bench or swing in there and enjoy the shade or surrounded by self-watering pots or planters of shade-loving plants (such as impatiens, caladium, coleus).
To enrich the soil, nuetralize the acid, and irrigate, not to mention finding a seed which is tollerant would be a yearly hassle.
C.T. neutralize the acid, reseed with a shade tollerant strain of grass irrigate well. those trees use everybit of water they can get.
This greenthumb moment brought to you by your friends at IFish
[ 04-01-2003, 06:07 PM: Message edited by: cirrhosis-of-the-river ]