Hemp is Earth’s number-one biomass resource; it is capable of producing 10 tons per acre in 4 months. Hemp is easy on the soil,* sheds its lush foliage throughout the season, adding mulch to the soil and helping retain moisture. Hemp is an ideal crop for the semi-arid West and open range land.

*Adam Beatty, Vice President of the Kentucky Agricultural Society, reported instances of good crops of hemp on the same ground for 14 years in a row without a decline in yield. Beatty, A., Southern Agriculture, C.M. Saxton & Co., NY; 1843, pg. 113. USDA Yearbook, 1913.

Hemp is the only biomass source available that is capable of making the U.S. energy independent. Ultimately, the world has no other rational environmental choice but to give up fossil fuels.
http://www.jackherer.com/chapter09.html