Horace Heffner wrote > > > The problem with regard to nitrogen fixation and other soil depletion > is the not that it *can* be circumvented by judicious management, but > rather what *may* actually happen and what is actually proposed to > happen. For example, elephant grass is touted as the solution to > ethanol production in northern latitudes. However, see: > > http://www.fao.org/ag/agp/agpc/doc/Gbase/DATA/Pf000301.htm > > "A complete fertilizer mixture may be needed for establishment > according to soil fertility. In Tobago, West Indies, a crop of > elephant grass removed 463 kg nitrogen, 96 kg phosphorus and 594 kg > potassium per hectare per year. The optimum phosphorus content of the > dry matter for growth was determined as 0.248 percent for the purple > type and 0.215 percent for the green variety (Falade, 1975). High > rates of nitrogen generally give good responses (Walmsley, Sargeant & > Dookeran, 1978) especially in the third and subsequent years when the > native soil nitrogen has been exhausted (Vicente-Chandler et al., > 1953). The latter authors suggested that the highest yields could be > expected from cutting at 12-week intervals and applying nitrogen > after every cut." > I got into using agricuturally produced biomass to support agriculture to maintain an available and affordable food supply in early 1970s. Using that resource to support gas guzzling vehicles with an ethanol blend on frivolous journeys wasn't part of the agenda. I teamed up with local consulting firm agro-economists and soil scientists and we arrived at. benifit/requirement ratio of 16 to 1 based on prudent agro practices, state-of the-art conversion of biomass to synthesis gas (CO + H2) for synthetic fuels using the Fischer-Tropsch process, and H2 for NH3 production using the Haber process.
Recycling of essential plant minerals was included in the effort. Fast Growing/Temperate Climate Bamboo species will produce over 40 tonnes dry weight per acre. I had some started from a few clones in my backyard. The yield was determined with the help of the local Ag experiment station http://www.pacificrenewables.com/fischer-tropsch.htm http://www.westbioenergy.org/lessons/les04.htm Although we were about a decade ahead of the pack, news of this "sunlight at the end of the tunnel" kept a lot of farmers whose energy costs had gone through the roof from throwing in the towel. Unfortunately contact with one large agro-business firm with a reminder about the fuel alcohol potential, turned them into government-subsidized alcoholics. > If oil hits $150 a barrel then it will be more expedient to buy > fertilizer and make a killing in a market which may not last than to > worry about crop rotation. > Good deal. Then sidewalk-footpath construction and closing shopping malls will employ those that lost their jobs to out-sourcing. Fred > > Horace Heffner >
