"Joel B. Gruver" wrote:
> The embodied energy costs of paraquat and glyphosate (roundup) are listed
> as 460 MJ/kg (Megajoules/kilogram) and 450 MJ/kg.
>
> My understanding is that both paraquat and roundup are typically applied at
> rates > 1 kg of active ingredient/ha (~ 1 lb/acre) when used to burn down
> weeds/cover crops prior to no-till planting.
>
> Thus the energy cost of the burn down spray in no-till systems is often
> greater than 450 MJ/kg.
>
> To put this in perspective, the embodied cost of a single burndown spray
> appears to be similiar to the energy costs of a primary tillage operation,
> a secondary tillage operation and several cultivations all added together
> (e.g. Loomis and Connor report that moldboard plowing medium textured soil
> 18 cm (7") deep has an energy cost of 210-370 MJ/ha).
>
> When it all boils down however, the energy costs of tillage and herbicides
> pale compared to the energy cost of N fertilizer. Loomis and Connor report
> that N (NH3) fertilizer has an embodied energy cost of ~ 60 MJ/kg. A
> typical application of 100 kg N/ha would have a total energy cost of 6000
> MJ/ha !
What does this mean to me as a farmer?
Steve Groff
"Enhancing the Environment" http://www.cedarmeadowfarm.com/
Cedar Meadow Farm
679 Hilldale Road
Holtwood, PA 17532 USA
To Unsubscribe: Email majordomo@cals.ncsu.edu with the command
"unsubscribe sanet-mg". If you receive the digest format, use the command
"unsubscribe sanet-mg-digest".
To Subscribe to Digest: Email majordomo@cals.ncsu.edu with the command
"subscribe sanet-mg-digest".
All messages to sanet-mg are archived at:
http://www.sare.org/san/htdocs/hypermail
This archive was generated by hypermail 2b29 : Mon Jul 03 2000 - 12:00:34 EDT