by MrBill » Wed 27 Feb 2008, 05:05:33
max_in_wa, N[sub]2[/sub] fertilizer can be made using natural gas, of course, but there is no shortage of nitrogen. It is as common as the air we breathe.
$this->bbcode_second_pass_quote('', ' ')Anhydrous Ammonia
Anhydrous ammonia (NH3) is produced commercially by reacting nitrogen gas (N2) from the atmosphere in the presence of a catalyst with steam and with methane (natural gas, CH4). The tonnage of anhydrous ammonia used in agriculture is greater than any other form of nitrogen fertilizer due to its lower cost per pound of nitrogen and its relative nutrient density (82% nitrogen by weight) which keeps the transportation cost per ton of nitrogen as low as possible. Anhydrous ammonia is a gas at normal temperatures and atmospheric pressure but converts to the liquid state when sufficiently pressurized. The need for pressurized containers and additional personal safety precautions reduces some of the advantages for anhydrous ammonia over more easily handled forms of nitrogen.
All other forms of inorganic commercial nitrogen fertilizer are derived from anhydrous ammonia. They are more expensive per pound of nitrogen because of the additional processing steps involved in their manufacture and greater transportation costs because they have lower nutrient density than anhydrous ammonia. These other forms of nitrogen fertilizer have advantages in terms of personal safety and ease of storing, handling, and application which make them attractive to many farmers in spite of the higher cost per pound of nitrogen .
Many posters get confused with the economics of how we produce nitrogen fertilizer today - using natural gas as a cheap feedstock - and how we might produce that fertilizer in the absence of cheap, abundant natural gas. It becomes more expensive not unavailable.
Sort of like comparing petroleum to alternative energy. The economics just don't work, so long as you still have petroleum in your current energy mix. However, remove petroleum from that mix, and all of a sudden you're comparing the economics of wind, wave, solar, hydro, bio-fuels, etc. with one another. Once petroleum is gone you move onto to your next best alternative(s) for your remaining energy needs.
Also, with regards to scalability there is a huge difference between trying to run the world's existing infrastructure with our current alternative energy mix without petroleum. It likely cannot be done. But that is a different argument as to whether we will have enough alternative energy to grow food. Clearly we will.
We have two or three smaller tractors on the farm that are essentially sitting idle, but were working when we parked them. And we have a newer tractor with three-point hitch and front-end loader. Plus another small Ford tractor that we use to pull the gang mower. Nothing by modern, large industrial farm standards, but enough to farm 160 acres if push came to shove. They can run on bio-diesel just as well as conventional diesel.
Some posters are way off base when they think farmers will not allocate enough production to bio-fuels to farm their own land. Even with a big garden those rototillers and plows save a lot of manhours. The cost of bio-fuel will always be cheaper than feeding a team of horses year-round and/or hiring extra hired men to do the work of a small tractor.
CNH in Germany is already introducing tractors that are designed to run on bio-diesel. Forget running electric cables over fields. This is craziness. The cost to electrify the countryside would be enormous and outweigh any benefits what so ever. Especially, if coal and renewables are used to help produce that bio-diesel.
The bottomline is that food and fuel are getting more expensive to produce. The more fuel costs the more food will cost. That will reduce standards of living and cut discretionary spending. However, that does not mean we cannot produce enough food. If you read the link I attached you will also see that crop rotation and planting nitrogen fixing crops such as legumes and grasses also play a role in sustainable agriculture.
The economics of farming have been so poor for the past two decades that farmers were squeezed between rising input prices and low farmgate prices for their products. This meant a heavier reliance on 'cheaper' inputs like artificial nitrogen fertilizer to maintain yields versus more traditional crop rotation and using organic fertilizer. However, those economics are changing due to higher food prices.
Soil erosion, salination and falling water tables as well as climate change pose as much or more danger to our future food security as does post peak oil depletion and eventually falling natural gas production.
But we really do not know how much nat gas can be extracted? As the price is so low, it is locked-in and unprofitable to extract in some cases, and while there is no demand for new fields, we are not even exploring for those new finds. In N. Canada the nat gas drillers have been essentially idle for two years now. It does not pay to look for gas or build pipelines at the moment.
However, you are right, "Subtract out the fertilizer from our farm equation and it wouldn't matter if we had fusion powered combines -- they'd have nothing to process." Therefore, it would be folly to rely on yet another finite resource like nat gas for all of our nitrogen fertilizer needs despite the economics today! ; - )
The organized state is a wonderful invention whereby everyone can live at someone else's expense.