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125 comments on Post-peak mechanized agriculture: the RAMSES project
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125 comments on Post-peak mechanized agriculture: the RAMSES project
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Broadacre cropping in prairie or rangelands with fields of say 20 hectares/50ac needs machines with 100kw or bigger engines. These are for tasks like disc plowing, harrowing and combine harvesting. Perhaps when there is no diesel or NPK this form of agriculture will dwindle. For starch we will eat potatoes instead of wheat products and they will be fertilised with compost and humanure.
However vegie growing may be easier than broadacre. I've heard that friable soils can be tilled into ridges with implements towed behind a tractor as low powered as 35hp/26kw. A blade weeder next to the tynes can sever the roots of weeds without needing chemicals. The field size might be say 1 ha or 2.5 ac. An hour's full work by a battery tractor will therefore need 26 kwh requiring a huge battery pack in a machine double the power of the vehicle illustrated.
Even better might be a gantry system whereby rectangular plots of say 20m by 100m are enclosed in rail tracks. This is currently done in tree seedling nurseries and some forms of vegetable growing. A tracked tillage machine of just a few kilowatts in power should be able to perform most tasks but we are talking 'field' sizes just 1% of typical wheat fields.
Therefore I believe the long term solution way post Peak is to farm at both extremes; natural gas powered machinery for large fields and tracked systems for small plots. That means battery powered tractors miss out; they are not powerful enough for cereal cropping nor are they as efficient as gantry systems.
Somehow I just don't see this working ???
"I've heard that friable soils can be tilled into ridges with implements towed behind a tractor as low powered as 35hp/26kw "
But for how long ?
How many KWhrs to prepare and plant an acre ?
The tractor in this link looks to be about 60 hp/45kw. It needs an hour per hectare or 24 minutes per acre in an already well tilled soil. So I make that about 18 kwh per acre. A blade weeder and clay soil could increase that energy requirement considerably.
Remember that diesel (45 MJ/kg) has 450 times the energy density of a lead acid battery (0.1 MJ/kg).
On the presumption that mains electricity is
available for farming a solution is to provide
overhead supply as is done for trolley buses.
Two wires and the pickup on the roof of the
harvester etc.
It would need lines of poles across the paddock to
support the wire.
I suspect that this would be a lot cheaper than stacks of batteries that would need replacing at
intervals.
It would make the area between the poles unusable
but would be a small penalty for the almost unlimited
power that would be available.
The separation between rows could be quite large as
trolley buses can move right across multilane highways.
Good idea. Even that might not even be needed if human labour becomes cheap - just run cable direct from the power source to the tractor on trailing power cable, with a few farm workers managing the cable as it snakes behind.
There is this possibility of using rails or overhead wires to power tractors It has been done in the 1930s. It may come back; in this case we'll have hybrid systems. Batteries will still be needed for going around and for light work, but when it is time to go for the heavy work, the machines would be connected to the grid. Right now, the RAMSES vehicle is not made to run on an extension from mains, but it could be modified very easily to do so. Maybe it is the way of the future.
Maybe they miss out of your prediction of the future, but I think we may well find ourselves going NOT to the extremes, but back towards the boring middle. These machines are in a managable human scale, not too far beyond the team of Horses or Oxen that defined Ag a century or more ago, and apparently of a size that is managable for upkeep, maintenance and modifications. Many castings and machine-finishing could be handled on a local level.
Beyond that, they are technically/electronically very simple, and can be built or retrofitted from VERY robust base-vehicles.
Here is a great testimonial quote from a farmer that converted an old Allis-Chalmers 'G' from the 40's to Electric Power.
http://www.flyingbeet.com/electricg/
I like the gantry idea myself, and have toyed with thoughts of very light rail running between fields as well, where rolling stock would cover a span between sets of track to fly equipment over the fields (Which one would orient as long straightaways, obviously..) but I haven't worried myself with any feasibility studies on them.. just chewin' cud.
Agreed, jokuhl:
Much of this discussion seems to ignore timescales. Surely we can agree on the extremes: barring global war or pandemic, there will be diesel to run tractors for the next few decades. Equally true is the fact that ultimately (a century?) it will be too expensive and inconvenient to produce and distribute all of that fuel to far-flung, large-scale farms.
Sorry, but those urban gardens will never "feed" us, meaning produce most of our calories. Sure, they'll give us fresh vegetables, but unless you have big nut trees in your yard, you and your spouse won't be growing the 1.5 million calories that you two need each year to stay strong.
What I don't get is the continued attraction to high-tech fixes, especially in this community that recognizes and often preaches the need for resilience and self-reliance. Five or ten years is a mighty short horizon for replacing all those heavy, toxic batteries, decade after decade. We could back off from the "90-10 rule" and still get most of the performance from a lot less sophisticated system:
http://www.agsem.com/AveryUndermountSteamTractor-1024.jpg
External combustion engines can run on locally produced waste biomass, and be simple enough to maintain without a EE and a lot of replacement PCB's.
Steam tractors bridged the gap between draught animals and diesel machinery once before - maybe it will happen again.
Steam works, but stirlings work better. Lots more power/fuel rate. And they work just fine on raw biomass. Just stuff it into the burner, or if you like, pelletize it. Stirlings can be made about as powerful/volume as diesels, and can be made to just make electricity, not turn a shaft, which makes them cheaper and very long lived.
References? Lots. Look up automotive stirling programs of 30 years ago. Also look up present space isotope power programs.
Electric motors are great. And as to batteries, it always seems so obvious to me that you make the battery pack separate so it can be replaced instantly (almost) when depleted. Especially easy to do in farm equipment, where a big box sitting out in an easily grabbed place won't cause the owner to faint from aesthetic shock.
Now I am gonna sit back and await the usual counter-groans based on the "not been done and therefor never can be done" argument. Sigh.
Stirling engines work great for silent non nuclear submarines where they turn generators by burning liquid oxygen and diesel. And two Swedish companies have recently started small scale series production to export for the solar power market. I see no problem with using such engines for wehicels if you allow them to be a little bulky and it has been done. There are also initiatives to use them for miniture combined heat and power plants. There are no technial hurdels left as far as I know but the cost for the machined parts, it needs too manny high spec parts to be dirt cheap. But if people pay more it would probabky be fairly easy to retool car engine part factories and car engine factories for making them by the tens or hundreds of thosands per year.
Not a "counter-groan" but just asking 'cause I don't know:
It seems to me that in a tractor high torque at low rpm is a good thing.
I know electric is great for this, but it seems the costs and complexity (of the generation and storage, not the vehicle itself) are a killer.
How does Sterling compare to traditional piston steam in this respect?
Good comments. Thanks. What I was thinking of was a biomass fired stirling being an on-board battery charger. The electric motor gives all the torque. So, we still have sort of a solar powered electric tractor, except by a different route- solar to biomass to stirling to battery to motor, rather than same except solar to PV, etc.
Of course, you could leave the biomass-stirling- generator on the ground, charging that quick-change battery going into the tractor.
Electric motors are so good!
BTW. We can make stirlings with no higher demands on machine tolerances than IC engine. Only thing somewhat special is the hot end- has to be at least stainless steel. Cast iron or other dirt cheap stuff won't do. Behind that hot end, rest of it is just another piece of iron, nothing fancy. The Swedish stirlings are great, but have the advantage that cost-no-object, given their use. We can make things far less fancy for tractor-biomass, where nobody's life depends on it (we hope).
Boof,
The wheat fields of Canada, Australia and US were farmed by horse drawn plows and harvesters prior to 1920 so it must be possible to farm with considerably less than 100hp tractors, not as efficient, probably a smaller width plowed.
When I lived in NSW I bred draft horse crosses (Percheron X thoroughbred) that grew over 17 hands tall and weighed 900 kg. I've towed a mouldboard plow and harrows behind these clumpers and I can tell you a tractor is simpler and more reliable. I think we should shake off this myth of going back to horse drawn agriculture. Unless world population reduces 90% or so. Some friends in Australia used to mail order draft horse harness from the Amish. All good fun until food shortages start in earnest.
I agree that a lot of future farming will be within city limits. Not so much community gardens for dabblers but high yielding farms run as a business.
While I agree that ultimately mechanized farming will collapse, i don't agree that it will be the first thing to go. In the Panic, before we run out of oil, the governments will direct enough oil to agriculture to ensure basic food supplies.
Growing 100 Ha or more of wheat or soy beans with large scale machinery is going to be the only way to avoid mass starvation for quite while. There is plenty of useless stuff carted around our highways at the moment, burning up very precious diesel that will simply be denied supply in order for broad acre crops to continue.
Ag will have to do its bit. We may see the return of droving where livestock do alot more walking and a lot less feedloting in order to keep the tractors and combines going in the wheatbelt.
Delivery of produce direct to consumers will mean bypassing processors that assemble tasty packaged goods from ingredients shipped in from everywhere. Town millers next to bakers may return rather than the absurd situation today where bread is trucked to supermarkets from more than 300km away. Ditto for breweries.
After the Panic, when reality dawns on us that BAU ain't coming back, we will need to resurrect the rural rail lines to bring the crops, wool and livestock to the cities and fertiliser back to the country.
Term- May I rephrase your thesis here as follows?:
"In the Panic caused by governments' lack of foresight in the face of many warnings of the coming oil crisis, those same governments will have the foresight to direct enough oil to agriculture, even at the time when they are deluged with more immediate problems such as coping with disorder and crime and economic chaos and inability of many key personnel to get to work".
Hi Boof,
How about this one? In my garden I do not turn the soil but use a light torching ( with propane) On weeds and cover crops. leave this to stand for a few days till the scorched leaves weaken the plant and then use a horizontal blade with a (me) powered tiller, rake and seed. I have a rototiller bought years ago but it is more trouble than doing it the above way. As well, I seem to get less later weeds this way. Maybe up north here instead of horses I could use a husky or two if I wanted to get serious and do grain on acerage:)
On the north coast we get lots of rain and so I also try to cover a lot with poly and that makes the soil a treat to work with in the spring, it ends up just moist enough, very friable and with black poly no weeds. More we do that way the less need for the plough or shovel.
I am sure there are a lot more simple low impact labour/fuel/beast savings devices about that one could use like a 'water wand ' made out of half inch poly pipe about 8 or 10 feet long with a small shutoff. I use this to dig and water plant holes in one action, reduces a lot of stoop labour and also great for watering individual plants down at the roots. ( incidentely if one sticks this in the soil about four or five inches and turns it on, very suddenly, it makes a happily satisfying explosion and chucks stuff in the air.
I worked briefly once with a local one and found it very trying attempting to get anything serious done - more time seemed to be spent having meetings about having other meetings or eating pot luck horribles.
Boof,
Who's talking about going back to horses, I said you don't need a 100hp tractor if a few horses could plow broad acre crops.
We farmed with draft animals but in 1915 we had 36 million acres of oats and 75 million acres of hay - the peak acreage dedicated to biofuel production. We go back that direction and we end up with meat as a condiment - something's got to give somewhere in terms of grain production.