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Posted on January 28, 2015 | 39 Comments
Tom has been pestering me for a while to say something about the synthesis of nitrogenous fertiliser using renewable energy. Originally I planned to write several lengthy posts with lots of data and references on this point in particular and on fertilisation in general, but I’m just too darned busy. So here is a briefer and less polished working through some of the issues.
1. Organic Fertility & Its Critics
There’s a wider context here, which is the onslaught against the supposed inefficiency of the organic approach by proponents of so called ‘conventional’ farming on websites such as Biology Fortified, Applied Mythology and SkeptEco. The same onslaught has spawned a thicket of papers and op-eds along the lines of ‘Can organic farming feed the world?’ to which your humble blog editor has, somewhat to his regret, himself contributed. ‘Somewhat to his regret’ because as I understand it around 60% of global nitrogenous fertility comes from organic sources. And we’re asking ‘can organic farming feed the world?’ Shouldn’t we be asking ‘can conventional farming feed the world?’ OK, I accept that organic & conventional farming aren’t entirely reducible to their respective approaches to nitrogen but, c’mon, who’s zoomin who?
Part of the anti-organic onslaught, I suspect, derives from the fact that the presentiments of the organic pioneers about the need to conserve and husband soil organic matter is now confirmed as a rock solid scientific certainty, an ‘inconvenient truth’ for its critics who then feel the need to run organics down in other ways. But I suspect the future shape of farming won’t be determined by partisan opinion-spouters on either side of the organic/‘conventional’ divide. Consider the following statement,
“It is both totally logical and cost-effective to use the resources you already have available in the most efficient way, before you invest in additional inputs…. Soil gradually loses condition, with modern day farming practices requiring it to withstand greater pressures, yet its health is often overlooked, even jeopardised through the use of acidifying fertilisers”1
Who is this outrageous provocateur for the organic way? None other than Hugh Frost, Product and Technical Manager for Mole Valley Farmers, my local agricultural merchants who supply and advise the largely ‘conventional’ farmers in my neck of the woods. It’s interesting to note such comments from a ‘conventional’ farming insider making an implicit ‘organic’ critique of ‘conventional’ practices without the need to mention organic farming at all. So let us be clear – aside perhaps from those benightedly arable-ised regions of the earth intent on mining to death the rich soils bequeathed them by nature, synthetic fertilisers really ought to be a last and not a first resort.
2. Spare the land and spoil the child
Nevertheless, it’s true that per hectare yields of most organic crops grown in present circumstances are lower than those of ‘conventional’ crops. This prompts the so called land sparing-land sharing debate, which essentially boils down to asking whether it’s better to grow intensively with scorched earth ‘conventional’ methods (including more synthetic fertiliser) on a smaller area and leave the rest of creation to the wild things, or to adopt a greater agricultural land-take albeit with organic methods that are hopefully more nature friendly.
To me, this sparing-sharing contrast seems overdrawn, for the following reasons among others:
The last point gives me my title for this sub-section. The eco-panglossians enthuse about getting people out of allegedly ecologically destructive peasant farming and into the cities where they can get an education and become proper, caring environmentalist citizens who pay their annual dues to Greenpeace. I’m sure they’re right that rising Greenpeace subs correlate with urbanisation, but so do all the consumerist behaviours that give Greenpeace its raison d’être. Anyway, more on that another time.
3. There’s more to life than bread and nitrogen
The debate about farmland fertility is heavily focused around nitrogen. That’s fair enough up to a point as it’s a critical plant nutrient, but it’s also just about the easiest one to furnish provided you have enough energy to hand. Maybe some day humanity will be able to take care of nitrogen for good thanks to abundant clean energy and Messrs Haber and Bosch, in which case other plant nutrients that are harder to supply will become limiting factors. That doesn’t mean of course that we shouldn’t aim for renewable nitrogen, but it’s not a case of clean energy + Haber-Bosch = job done in agriculture.
Likewise the debate about agricultural productivity is heavily focused around cereals and grain legumes. Well, we all need our calories and protein and there are a lot of us on the planet. But just as plants need more than nitrogen to be truly healthy, so do people need more than tortillas and beans. Let’s hear it for vegetables, and rein in a bit on the calories per hectare malarkey.
4. Drugs: just say no
Elsewhere I’ve likened fertiliser use to illicit drugs: it gives us a nice quick hit, but with bad long-term consequences for health, if not necessarily for our own health then at least for the health of those anoxic downstream aquatic environments where our fertilisers get flushed, and in relation to associated carbon emissions. That probably goes for all forms of fertiliser, including organic, but especially for cheap and soluble synthetics.
The other parallel is addiction: once you’re on the drugs/fertiliser treadmill you’re buzzing, and it’s hard to get off, as evidenced by the spiralling demand for pork, chicken and other such temptations. There are equity issues here, which I’ll post on soon. But the larger point is can we ever say no, we don’t need more of this, we’ve got enough? I’m not seeing it in the way that the global food system works, just as you don’t tend to find too many abstemious and judiciously indulging crack addicts. If we’re going to ask questions like ‘can organic farming provide enough food for the world’ we first need a proper discussion about how much is enough.
5. Sustainable addiction
But OK, OK. Having said all of the above, I’m not so censorious that I think nobody should ever use any synthetic fertiliser, just as I don’t think it’s always wrong for anybody to take a narcotic hit if they want to. So, if we first attend to endogenous organic fertilisation, diversify our agriculture away from an obsession with economic growth and per hectare productivity of grains, and clean up the way we produce and dispose of nitrogenous fertiliser then, to answer Tom’s question, yes I think there could be a place for synthetic nitrogen fertiliser made with renewable energy on farms.
But I’d like to ask a few questions about what this might involve. Somebody whose chemistry is less rusty than mine may be able to better confirm this line of thought, but my feeling is that nitrogen is the kind of element that likes to play alone. It requires an awful lot of energy to persuade it to come out and play with its hydrogen buddies. And if you’re doing so with renewably generated electricity, my guess is that it would take even more energy than ammonia synthesised from coal or natural gas, because you’d have to work harder to get the hydrogens to play along. The figure in the back of my mind for the energetic cost of modern ammonia synthesis with natural gas is 36 MJkg-1. I’m not sure if that’s per kg of nitrogen or per kg of ammonia (can anyone help?) DEFRA figures suggest that applying 150kg of N per hectare (or even more) is not uncommon for arable crops. So let’s propose a small farm situation in which annually the farmer fertilises one hectare with 150kg of fertiliser at a (very conservatively estimated) 40 MJkg-1. I think that would be a requirement of 150 x 40 = 6000 MJ – which by my calculations is about the amount of fuel energy you’d need to drive an efficient modern car about 3000km (that’s Lands End to John O Groats, back to Lands End then back to John O Groats again before you run out of gas on the fourth leg somewhere in the southern highlands). Quite a lot of energy in other words.
Now, having been living off grid and renewably generating my own electricity with PV panels and a few other gizmos for the past 3 months I’ve developed more than a passing interest in renewable energy performance. We have 12 PV panels rated at 200W (oh, I’m so looking forward to the summer) and a 3000W inverter, which means we can’t really use power hungry things like electric stoves and kettles. Still, we’ve got by pretty well over the winter with a fridge, LED lights, charging laptops, powering drills and angle grinders, and doing the washing on sunny days. For most of the heavy lifting domestic energy usages, however, we’ve burned wood or used bottled gas. Our total electricity use in 3 winter months has been about 200 KWh = 720MJ. So let’s generously estimate an annual usage of 5000MJ – not quite enough to produce our 150kg of fertiliser. And that from an electricity system that costs about £10,000 to install new (though hopefully it’ll last a long time). I guess some of its pricey components like batteries and inverters may not be needed for a fertiliser synthesis system, but presumably there’d be other costly elements in such a system.
Bottom line is I’m not convinced that the best way to go for me in terms of on-farm fertility is to generate electricity and then use it to make fertility. I think electricity is best reserved for the things you really need it for, like computers and power drills, and fertility is best taken care of organically. Doubtless it could be shown that it’s not very efficient producing small amounts of fertiliser using small renewable installations on small farms, and that it’s better to scale up industrially and sell the fertiliser to farmers. But then we’re back in the ‘economies of scale and simplification’ loop that the small farm movement is trying to break out of.
My alternative suggestion is this: develop and incentivise bioregional farming systems that take care of as many of the local population’s needs for agricultural produce as possible using biotic fertility. I think people may be surprised at how much is possible, but also at what has to give and what new thinking is required. If that proves inadequate to your region’s needs, then develop an expensive certification system allowing farmers who fulfil the appropriate criteria and demonstrate their ability to safeguard downstream ecosystems to purchase synthetic fertiliser from renewably-powered industrial units, provided their products are stamped with a label stating ‘Certified Non-Organic’. Data on the proportion of certified non-organic produce consumed in each region would then be collected by national agriculture departments and used in regional sustainability indicators, which could inform economic policies to incentivise reductions in the use of precious electricity to synthesise fertiliser.
Well, it’s a thought.
Notes
1. Frost, H. 2014. ‘The soil’s digestive system – improving nutrient uptake’ MVF Newsletter, No.601 June 2014 p18.
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Thanks as ever for more meaty thoughts to consider. And I’m still not finished thinking this whole post through. Like you I’ve some other issues to attend to. But one thought struck me that might be worth writing down as I’m thinking of it.
Has farming gotten so diverse that we might want to be more specific in our use of the term?
As a younger scientist we were usually pretty specific in distinguishing agronomic crops from horticultural crops. Universities had at least two distinct departments – one for each. Now its more common for these two crop ‘types’ to share a single academic department – but the uses of our domesticate plants has expanded beyond the older Ag. models as well. Miscanthus is a new crop since I got started; biomass crops are either new or the breeding objectives have evolved from pasture/range suitability to now include biofuel processing uses. Sometimes the objectives overlap and nothing new is needed – but in other considerations there is a direct need for completely different breeding because traits needed in one end use are detrimental in another application. Corn can be bred for better use in ethanol production… but don’t grow it around corn destined for chips. Switchgrass is an example of a forage and a biofuel feedstock. The name is perhaps more apt today then when it was first christened… as now a producer can switch between two markets with it. 🙂
I went through all that because one of the realms where you and I might stand on opposite sides of an argument about agriculture and ‘conventional’ farming is more outside the realm of food production. Perhaps biofuel issues might better be debated alongside other renewable energy issues. The allocation of arable acres for non-food end products can reasonably be debated in terms of long term sustainability… but while we still have enough food to go round I’m not convinced that we have to prevent entrepreneurs from using their land to produce an economic resource (earn a living). Now if this latter land use is ultimately poisoning the environment and ruining a natural resource then its another matter. Externalities must be considered in agricultural pursuits just as they should in other human activities. But if the production isn’t despoiling anything, just having this non-food plant based production capacity in place would seem to me to have an additional value as a buffer – built out capacity and infrastructure that might be more rapidly converted to food production as needed. So just as cereals have been mankind’s darling over long history because they store well (and cheaply) – allowing survival in times of hardship… so too might the infrastructure allowing a rapid ramp up (or switch to) food production might serve as a hedge against calamity.
Just a thought.
Interesting response as ever. Agreed that entrepreneurs shouldn’t be prevented from earning a living from their land, but I’d prefer to see a policy environment that made it easier rather than harder to do so by producing food rather than non-food crops. On the issue of non-food crops as buffers, I think this is an interesting and worthwhile point – but my top of head response would be that it only really works in situations of a relatively autarkic and relatively egalitarian farming economy. Otherwise the signal to intensify is readily ignored by the wealthy land controllers at the expense of the poor, or else is exported geographically to somewhere else that can take up the slack. The latter scenario is actively favoured by the ‘gains from trade’ school of economic orthodoxy, which may be fine up to a point (notwithstanding the need for that ‘how much is enough’ discussion I mentioned), but once the ‘slack’ has been taken up globally, perhaps that’s when you get the land takes and the environmental bads that we’re currently witnessing…
The ‘how much is enough’ discussion is way overdue. And I sense the two of us wouldn’t be too far apart on our particular stances there.
So far as switching land uses in response to market signals – I can only offer an opinion based on interactions with several dozen Midwestern US farmers. This particular population would be heavily biased toward large scale row crop producers (read corn, soy, occasional wheat). Many of these growers will watch the markets over the winter period both for signals of when to market the crops they have produced, but also for signs to determine how much of various crops to produce in the coming season. Very few (only one I can think of) have ever confided that they would abandon their current rotational sequence completely to respond to a market that strongly encouraged one crop over others (eg., plant 100% corn because of market signals). Thus, even in the face of potentially lower returns for the different crop most appreciate the value of rotation and will maintain at least some. One relatively large grower near me has suggested he will switch from a 50:50 corn:soy to 60:40 corn:soy if market signals favor corn significantly. Other market forces impact decisions as well. Many future planting decisions will be put in place before a current season’s crop even comes out of the field. Early order and early pay discounts for seed are very common and can be significant enough to offset the more common differences one can expect in market calls for different commodity crops. Having a significant proportion of your next season’s seed on order will dampen an urge to ‘play the market’ – at least in terms of future acreage allocations.
Crop insurance issues, government programs, and in season weather issues can also influence which crops end up in which fields. But for the vast majority of producers I have encountered all these market indicators/forces will get in line behind the long term best interest of the soil(s) they are working. Rented land may get a bit less consideration than owned land, but even rented land is seldom abused by a grower who aims to stay in business.
Interesting – I guess I was thinking more about the overall policy drivers towards how and what we farm, than the more micro decisions farmers may make year by year in response to prices of the kind you mention. But I’m interested in your thoughts based on a very different agricultural context to my day to day one…
Its interesting to hear an acreage allocation decision referred to as “micro”. I get that it isn’t exactly where you were headed, but if the farmer I was thinking of above switches from a 50:50 corn:soy allocation to a 60:40 allocation this is a switch of nearly 300 acres. Hardly micro to me. Sometimes scale can surprise us.
Perhaps more to your point – there are some situations I’m aware of where popcorn is grown under contract, field tomato for canning (single pass harvest), or sweetcorn for canning/freezing. These are done in proximity to processing facilities (though popcorn can be more easily farm stored and shipped – so proximity there is less important). These three examples of rotational choices are available to some enterprising broad acre farmers here. But the need for more specialized management and equipment makes these operations more rare. Indeed these crops (sweet corn and tomato esp) are more horticultural and this goes back a point I was making in the first reply of this thread.
My personal experience with commercial vegetable production really ended a very long time ago (but see the reply to Brian below). Commercial scale vege production in this part of the world would look as foreign to me as it might to you.
Yeah, 300 acres isn’t micro at an individual level – certainly not to this individual in view of the pitiful acreage I tend, but I guess I’d argue that it’s still micro at the level of overall national or global food policy.
Great, I ask a civil question and this is what I get. Pestering indeed! The reason I asked was because I had to fertilise some blueberry bushes. Now everything I was doing with these very pernickety plants was wrong and I considered my only recourse was to use a non organic fertiliser, not to mention sourcing the ericacious compost it was sitting in or get no yield at all – or worse slowly kill the bloody things.
Now I know the trials and tribulations of us poor urban types doesn’t compare to the righteous, nay holy, endeavours of the farmer but I am reminded of a certain individual justifying the use of glyphosate, therefore illustrating that sometimes compromises are made for the sake of practicality without the ecosystem suddenly dying because of our wickedness.
I thought it might be nice to chat about non fossil fueled based synthesis of nitrogen with someone who knew about such things but I wish I hadn’t asked.
Blueberries are tough to grow, no doubt. I’ve not even attempted them. We have a small bed in front of the house with rhododendron – another ericaceous plant. They survive, but thrive would be an exaggeration. I have considered gypsum to further lower the pH, but haven’t so can’t speak to its merits either. But a gypsum application can be used in organic methods, no?
Adding gypsum won’t change pH. It is calcium sulfate and is a buffer salt, made by reacting sulfuric acid, H2S, with calcium hydroxide, Ca(OH)2. If you want to lower pH your best bet is to add elemental sulfur. (Aluminum sulfate and iron sulfate would also work. Sulfur coated urea is probably not “organic”.)
http://web.extension.illinois.edu/cfiv/homeowners/080818.html
Organic matter can also help lower pH.
https://www.rodalesorganiclife.com/garden/what-do-if-your-soil-too-alkaline
Tom – do you know anyone near you with a successful blueberry bed? I ran across an article that talks about the benefits of mycorrhiza specifically associated with ericaceous plants. One of the benefits of the mycorrhiza in this instance is their ability to assist their host (the blueberry in this instance) in nitrogen uptake. If someone you know has a successful bed they likely have the right kind of mycorrhiza which you should be able to establish in your own bed with some soil from theirs as inoculum.
Further, if you’ve raised any garden legumes – peas, green beans, limas, etc then you already have some organic nitrogen fixation going on and the blueberry mycorrhiza could help your bushes take advantage of it (though the pH of the soil the legumes grew in is likely much closer to 6.5 than the blueberries would like (5 or lower)… I was curious about ericaceous legumes to go around this issue but could find none in a limited search).
Some acid loving plants that symbiotically fix nitrogen are actinorhizal. The symbiosis is with Frankia. They include bayberries (Myrica), sweet fern (Comptonia), and alder (Alnus).
Interesting research “Potential of coppiced alder as an on-farm source of fertility for vegetable production” at:
https://projects.sare.org/sare_project/ONE13-187/
Apparently some trefoils (Lotus) will grow in acid soils. Search “A Legume for Acid Soils”
Looking at my copy of “Revegetation of Kentucky Surface Mined Lands” I find that flatpea (Lathyrus sylvestrus), birdsfoot trefoil (Lotus corniculatus) and Lesepedezas (sericea and striata var. Kobe) will grow in soil with pH below 5.
There are commercial ericoid mycorrhizal inoculants. One is Empathy Ericoid Rootgrow.
Or we could look at it another way and say that 12 pv panels in a year could produce enough for a hectare’s worth of nitrogen regardless of conversion to equivalent driving miles. How much space does 12 panels take up? How long will they last? I am of course putting a lot of faith in scientists and engineers designing hypothetical small scale nitrogen synthesising plants….
Anyway 5000mj =1388.8888 kwh * 8.93pence (Sainsbury’s electric selling price) = £124, from a free source (the sun) once the capital has been paid off. So that’s the equivalent of one agricultural labourer’s wages for (I’m guessing) 2 days collecting biomass and then composting it. But then if we are using agricultural land to generate electricity why bother growing crops on it?
Is it fair to compare use of electricity this way? Take those wind mills that we used to see that pumped water up from wells. Did anyone ever say: look at that waste of wind power, you could have driven to lands end with the power that it generated?
The “Engineer” has already designed a solar powered small scale nitrogen fixation mechanism. It’s called biological nitrogen fixation, primarily Rhizobia and Frankia symbioses.
Tom, can I assume you’re joking and not really offended? I can’t see that what I wrote should upset you so, and there’s certainly no intention on my part to be rurally self-righteous…other than my usual schtick, which is to oppose the all too common problem of urban self-righteousness (not an accusation I’m levelling at you, I hasten to add). And pestering…well, you did accuse me of evading the issue!
But to address a couple of your points. The comparison with driving a car was mainly intended as a reminder that fertiliser synthesis is a very energy-intensive business…and I think my estimates of renewable fertiliser synthesis were probably quite generous. I’m sure you’re right that people didn’t used to agonise over whether to pump water or drive to Land’s End with their windmills, but that was surely because there was no possibility of using wind power to drive anywhere (except on the sea). Nowadays it’s possible to convert wind power to more versatile electricity and possibly use it to drive to Land’s End – but for that reason among others it’s surely appropriate to consider energy use priorities, whether as farmers or as societies as a whole. The more so when most of those energy uses have significant downstream consequences.
In terms of pricing, I don’t quite follow you – Sainsbury’s 8.93p/KWh is surely not a price based purely on solar energy? You also have to think about the rate of delivery – over the winter, our 12 panels have rarely delivered more than 1KW at a given time, so you have to think about the costs and efficiencies of extra generation and storage capacity and trade offs with your other on-farm energy needs. Doubtless the cost of renewable generation will decrease, but it’s intrinsically more diffuse so this will surely be an ongoing problem. And you also have to bear in mind as I mentioned above that soluble N is only one part of your overall soil input needs – neglect collecting that biomass at your peril!
On the glyphosate issue, well my point about it really was pretty much the same as my point here. If you treat it as a panacea and splash it around everywhere, it’ll soon become ineffective – as indeed it already has in some places – whereas if you use it more judiciously then maybe there could be a longer-term role for it. The problem is the tendency for our economic system to reward short-run gains over long-run dysfunction and therefore incentivise indiscriminate usages. Much the same with synthetic nitrogen. As I said above, I’m certainly not wholly opposed to using it in any circumstances, but I think we need to be thinking more in terms of that economic ‘how much is enough’ debate, rather than mistakenly assuming that a clean generation techno-fix renders that debate irrelevant. That’s why I dwelt at some length on the wider agronomic and social context before looking specifically at fertiliser synthesis.
Bottom line for me is that at present I can’t see a good case for N fertiliser synthesised on farm from renewable energy on cost grounds. Maybe that’ll change in the future – suppose renewable prices come down and fossil fuel prices go up…then farmers would face a lot of interesting choices. But in any case there are many wider contexts which also have to be considered, some of which I mentioned above, and which mostly boil down – as you correctly predicted a while back – to my view that we really need first to be asking those how much in enough questions. Still, if you’d like to try persuading me otherwise…
It was a back-of-a-fag-packet calculation. I got a U in chemistry and a C in physics so I stand by it unless I really mucked up the figures. I did another back-of-fag-packet calculation using the equation on this site
http://www.bbc.co.uk/blogs/legacy/ethicalman/2009/12/why_micro_wind_turbines_dont.html
….and googling what terms such as ‘power’ ‘watts’ etc actually mean and I reckon the windmill pumping water also comes quite close to what your solar panels are doing if it were generating electricity. So the point I am making is: is it an appropriate use of technology to pump water but not to spend the same amount of joules creating fertiliser?. Are you making a moral judgement? Is manufacturing nitrogen ‘bad’ even if it’s manufacture does not use fossil fuels?
I obviously get all the arguments about gathering biomass, you’ve known me long enough to know I’m passionate about it.
Your comment about reining in the obsession with calories per hectare is one area where we disagree. It is a moral duty of anyone who aspires to influence public policy on agriculture to have a strategy that feeds billions of people real filling food. Subsistence food that millions of peasants choose to grow for a reason, and then a little cash crop if possible.
Tom, it feels to me a bit like you’re trying to manufacture disagreements with me here.
1. “It is a moral duty of anyone who aspires to influence public policy on agriculture to have a strategy that feeds billions of people real filling food”. Yes I agree. But that strategy does not have to involve growing only maize, wheat and a handful of other crops to the exclusion of lower yielding crops on the grounds that the former produce more calories per hectare, particularly when a large part of those calories ends up producing meats, biofuels etc for the rich – maximising the calorific return of global agriculture will not in and of itself guarantee the equitable distribution of real filling food.
2. On nitrogen, no manufacturing fertiliser isn’t intrinsically ‘bad’. I’m not sure what I can say to convince you that I’m not fundamentally opposed to it other than what I’ve already written. But to stick with your feeding the billions theme, I would want to question why you think it’s a good use of global resources for farmers in wealthy countries with good soils to invest money in adding yet more fertility (however generated) in order to increase per hectare yields, when this has typically resulted in undercutting the capacity of small farmers in poor countries with poor soils who arguably have much more need of fertiliser than we do, as well as a whole bunch of downstream bads such as currently afflict the over-nutrified River Frome in my watershed.
I guess I’d take the view that generating energy in order to either pump water or synthesise fertiliser isn’t a particularly good use of resources for most farms in Britain – not a moral judgment, more a question of efficient design and long-term sustainability. Though I’d likely want to invoke Clem’s distinction between agriculture and horticulture in this connection. There are other places in the world where pumping water and making fertiliser may better commend themselves – though I’d still question the long-term sustainability of this. Since you mention subsistence farming, in these places (in fact, in all places) I’d suggest the wisdom of looking at the farming systems developed by subsistence cultivators through the ages in situations where the energy costs of fertilisation and irrigation are high. That doesn’t mean that I see no value in making use of cheap renewable energy today when and where it’s available – but efficient design surely points to active energy inputs as a last and not a first resort. To me, it wouldn’t make sense to install electric heaters throughout my house rather than insulating it, even if the heaters cost little. Same in farming – except that synthetic fertiliser DOES have costs…on the poor, and on the environment… so why not use it judiciously?
So this just passed into my inbox – a non-leguminous natural nitrogen fixation that could in time be implemented for small farms:
http://www.the-scientist.com/?articles.view/articleNo/42038/title/Nitrogen-Fixing-Bacterium-Could-Cut-Biofuel-Costs/
So the article is actually set up to discuss the N fixing capabilities of a bacterium that will ostensibly be used in the ethanol (biofuel) industry. But don’t let that rain on your imagination. I would be shocked if there were no means of adapting this sort of technology to one day run a small digester (think home brew scale) using coppice or similar plant cellulose feedstock. Ethanol produced could be used for fuel or ahem… ‘other’ applications – but of interest to the natural N fixers in the audience: there would be the distiller’s dry by-product (distillers dry grains or DDGs in the corn to etOH language). The advantage here over traditional composting (which is already scale friendly) as I see it – with composting you need to be careful of your carbon to nitrogen ratio (C:N) in the starting feedstocks to your compost pile. Here you can start with a carbon rich feedstock and get the bacteria to ‘fix’ the ratio. (aren’t puns fun?)
I’ll go out on a limb here and predict that there will be a homespun You-tube how-to video out within a year to demonstrate a homemade or DIY digester that will do exactly this. Now it may be pretty crude with some ‘still’ to be smoothed rough edges, but aren’t all new technologies like that? If its easy, everyone could do it.
My simple minded vision paints a portrait of a Mid Atlantic hill farmer with a still sittin’ in the shade with a mason jar of shine in his hand. When the revenuer shows up our modern biotechnician simply nods, and indicates that the still is being used to produce some Nitrogen fertilizer and that this clear liquid is just a by-product. Nothing to see here, keep moving.
Come to think of it, Brian lives in a perfect environment for just such a scenario. Hmmmm, I may need to make a little road trip :).
Look interesting Clem, I’ll try to take a look at that when I have the time.
Your speaking my language, Clem. I’ve got the still. Also, been wanting to set-up a household bio-gas digester for a couple of years. If I could get enough gas to power the stove on occasion I’d be happy. You can actually buy ready made household plants from China. Can’t find any reviews….
Chris,
What are some of your practices re: soil fertility there on the old homestead? What kind of limitations have you run up against?
Clem,
The same for you, what did your folks do to preserve the soil fertility off of highway 36 back in the day?
Cheers,
Brian
Brian:
First – the farm I grew up on was well south of Hwy 36… we did talk about Hwy 36 and gardens thereabouts earlier following a road trip you’d made. I owned a small farm a few miles north of Hwy 36 in Indiana before moving to Ohio. And if it makes the story any more complete, I used compost for the vegetable garden on the Indiana farm, but the agronomic crops there were fertilized with commercial fertilizer. The compost by the way was all plant based (no livestock) – a nearly two acre house lot with plenty of deciduous trees and abundant grass clippings yielded enough compost for a quarter acre garden.
The home farm was due east of St. Louis MO… in Southern IL. It was a mixed livestock, crop and vegetable farm. Dairy bull calves from surrounding dairy operations were castrated and fed out for beef. Their manures were spread for fertilizer. Hay fields were managed to maintain alfalfa (grasses like orchard and brome were present, but with good alfalfa the grasses tend to manage on their own) Pastures were occasionally interseeded with legumes like red and alsike clover, and birdsfoot trefoil (though I’m not sure this actually made much impact… not that it won’t, but that we likely didn’t get it done properly).
Rotation in the vegetable garden was pretty strictly followed. I recall the biggest motivation there was tomato placement. Tomato breeding for disease resistance has come a long way since I was a lad. But garden legumes like green beans, limas, crowder peas, fresh peas were also rotated with non-legumes to provide some nitrogen. Weed control was a combination of hoeing and mulching. Mulching with wheat straw has the advantage of suppressing weeds (which goes a long way toward enhancing the mood of the captive hoeing laborers – read me and my brothers) but also providing an in situ sheet composting. Carbon:nitrogen ratio becomes important in the latter system – too much wheat straw is not helpful, and specific amounts will depend upon sources of N to aid in eventual decomposition.
None of the gardening was done to strict organic methodology. While most every effort was made to avoid chemical pesticides or commercial fertilizers the motivation was more cost savings and keeping pesticides out of the reach of children. But if a pest issue (alfalfa weevil and corn earworm are two that come to mind) became important enough… chemicals were deployed. I still recall Dad’s instruction about using chemicals to spray sweet corn for earworm… learning to drive and passing a Rules of the Road test was easy by comparison [today I have a commercial pesticide applicator’s license… and feel as though I’ve had one longer than a driver’s license].
The sweet corn operation was the least organic – herbicide was used, and N fertilizer was routinely used.
Tillage – both in season cultivation for weed suppression and fall tillage to work residues into the soil (and suppress fall weeds) was common.
Clem,
Thanks for the response. It sounds like a fairly typical representational farm of the period for the mid-west or upper south. I’m sure you have fairly good recollections of that change from smallish farms with more of a house-hold economy to the larger commodity farms of today.
Were you aware of that change as it happened? Or was the change slow enough to only be observed in bits and pieces?
BTW you need to keep thinking about that blog idea. You have a good way of marshalling ideas into words pulled from the old gray matter (not that your matter is old or gray.)
And once again, we have trespassed on Chris’ digital world for our own amusement.
On our trespass: Hopefully we’re leaving sufficient value to cover the costs borne by our beloved host.
On having a front row seat for the past 50 odd years of agriculture in the U.S.: It has been quite a ride. As for noticing the changes – some have been gradual and others fairly rapid by comparison. Farm sizes have gotten larger at a somewhat mellow pace. Equipment sizes have gotten larger at about the same pace – though with perhaps a more erratic pace as technology has allowed engineers to accomplish some of the technical feats needed. Biotech changed things far more rapidly. And the technology used to do plant breeding has been changing over this time as well. Had one of my classmates been so naïve as to imagine earning a graduate degree would bring learning to a completion – well, I seriously doubt such a person would be doing this today.
On the matter of my matter being old and gray: accurate on both counts. But old is a matter of perspective. Gray – well that’s just a matter of pigment (or lack thereof).
On the matter of me blogging: part of me likes to think I’m already doing that [the trespass blogger] :)But I do think it may be more appropriate for me to set something up so that I’m the one who gets the snide remarks and arguments. We’ll see.
BTW, I just realized your Winged Elm Farm blog is being echoed from time to time at Resilience – how cool is that?
“On our trespass: Hopefully we’re leaving sufficient value to cover the costs borne by our beloved host.”
Indeed you are – really interesting to read about your lifetime’s experiences. Keep the comments flowing!
On my soil fertility strategy, I wrote a blog post about this a while back: https://chrissmaje.com/?p=508 . I’d like to say more, but work pressure…. Hopefully I’ll come back to it soon. Bottom line is we rely mostly on clover leys and imported woodchips soaked with human urine and other good stuff. But I’m not that happy with our SOM – that and human labour (plus modern economics) being the major constraints on our enterprise.
I’m interested in the straw mulch on Clem’s farm – a good idea in principle here, but in our climate it generally causes too many slug problems, at least in horticulture. Maybe works better in dryer climates with fewer slug problems?
Yeah, a bit of a pleasant surprise, that resilience coverage. Seems to only happen on their slow news days.
Re: Slugs. We have them, had them when I was little. They taste great parboiled and dipped in a little drawn butter – escargot. They go nuts for saucer of beer. If you’ve had trouble baiting slugs with beer it may be less the fault of your slugs and more the fault of your beer?? 🙂 [not serious, just a poke at warm beer]
But I will allow that perhaps your slug population is more ambitious and fecund than ours, and if you want to be organic even the less ambitious ones can be a serious aggravation. What to do?
We used to bale slug proof wheat straw exclusively. The only way to go. [not serious here either – sorry; but maybe the good folks at Rothamsted can get right to work breeding a wheat (or other cereal) with straw that is slug proof.]
Seriously though, the only suggestion I can offer to get at too many slugs in an organic situation (beside picking them by hand and/or beer bating) is natural predator control. There is a beetle that loves ’em and I’m fairly sure this beetle occurs on Her Majesty’s Isle.
As for mulching for weed suppression and strip composting… this is such a natural fit and SO beneficial for soil (reduces erosion potential, keeps surface layers from drying rapidly, feeds worms and other macro biota (alas slugs fit here, but…) … SO beneficial for soil that I would work diligently at solving the slug dilemma rather that give up on straw mulch (perhaps coppice mulch – or same problem??). It may be that you have to give up mulching some crops that are more impacted. Not sure if you’re raising tomato, but if you are – and doing it in an intensive manner for space reasons, then a mulch should be considered VERY important. Mulch can help regulate soil moisture and thus modulate fruit quality issues. Too much drying and wetting in a tomato bed will lead to cracking fruit, uneven yield maintenance, and just poorer overall performance. In a dry spell where you are needing to irrigate tomato – having a good layer of mulch will cut down how frequently a watering is needed. Saves time, labor, and energy. If I had slugs in my tomato patch, hand picking would be preferred over giving up on mulch.
Chris,
Thanks for the link to your older post. It has me rethinking a bit about our composting system. It is pretty much of the pile it up until it looks usable system. We do work with a few restaurants and collect kitchen scraps. Building piles, alternate with old bedding from the barn, gets hot pretty quick. But we have no Cordelia to police ourselves.
We also began composting our poultry mortalities and offal from butchering the past year. That seems to work out pretty good. “Pretty-good”, that seems to be my byword for how we farm. Clem probably is rolling his Yankee eyes and thinking “Damn Southerners.”
Cheers,
Brian
Now hold on there, I resemble that!
Wanted to suggest that composting offal is awful, but then in reality it is an excellent use of the bits not otherwise eaten. Just letting the pile sit will accomplish your fertilizing goals. And I’ll confess to having a sedentary pile out behind last year’s garden at this very moment. The one piece of your system that gives me a minor cause for concern is with carcasses or offal from all the various species on your farm I might be wanting to make sure the compost is pretty mature (well cooked as it were) before putting it out where animals might roam. Chickens in a garden prior to planting for instance, might have access to virus’ that were in previous chickens. I’m not expert enough on composting’s potential to pacify these threats, but I’m fairly sure the reason foot and mouth (hoof and mouth) is such a scary disease counts for why certain animal feeding habits are banned in some jurisdictions. And for what its worth, I just left a remark at Winged Elm – and turning the compost pile was offered as a physical activity worthy of consideration for its physical demands (which might keep one more fit – why pay for a club membership when a pitchfork and a compost pile are at hand??)
True confessions? As uncivil as it might seem, in these parts one can usually get the message passed by simply rolling the eyes and uttering ‘Southerners’ without any adjectives. Damn is usually reserved for Yankees.
Warm regards,
Trespass Blogger
I worked on a farm in Canada called ‘Good Enough Farm’, a name I’ve always liked. My byword is ‘not too bad’. Not quite sure where you’d place ‘pretty good’, ‘good enough’ and ‘not too bad’ on the spectrum.
Yes there’s much to consider when it comes to composting. We probably shouldn’t beat ourselves up too much about the sustainability of various composting practices, but I do see a lot of small scale systems involving heavy importation of bulky organic matter which get praised for their sustainability without folk thinking too much about the whole system implications.
One thing that I tell visitors, particularly those contemplating this life, is do not overthink it. That is not to say that one should not learn from their experiences, or that knowledge of farming is useful. But, instead, that “over thinking” leads to too much complexity. I usually blather on that slowness is better than over thinking. That when farming one should make his/her changes incrementally. Incremental is easier to correct than full speed ahead. I blogged on that notion this past Sunday. Although I think I watered the message down too much (sigh).
Heavy importation of stuff for composting should not be an issue if it fills a niche in our landfill crisis, right? It can be a problem as it relates to what you bring onto the farm (pharmaceuticals, heavy metals and other fun stuff.) But maybe you are talking about “sustainable farms” that are purchasing their inputs?
That reminds me of a lecture from a professor bragging about how he was bringing back sustainable hog raising to West Virginia. He even brought slices of cured ham, excellent. But he lost me when he talked about the grant funding needed to sustain his operation. The title of his lecture was “Sustainable and traditional hog raising”; an operation subsidized by grant writing acumen is neither.
Predictably I have veered off target. I think I hear some eyes rolling.
yep, overthinking indeed can be a problem – and one that I suffer from grievously. Along similar lines a friend yesterday mentioned to me the dangers of ‘over-designed and under-practiced’ permaculture.
My point about the importation refers mainly to the fossil energy costs of transporting bulky organic matter, which quickly mount to the extent that any energetic advantage over synthetics is lost. But yes, if it’s otherwise going to be trucked to landfill then better to truck it to the farm. The other question is where is it coming from, and mighn’t it be more sustainable to use it there? Other farms, people’s houses, cities, wilderness or wasteland, waste facilities – all have interesting implications…
“I think I hear some eyes rolling”
You, my dear friend, have incredible ears… or perhaps you are overthinking that too? 🙂
Farming wouldn’t be alone among vocations where there’s a need to consider how much is good enough. How much profit is good enough (who asks that??); how much grant funding is good enough; how much thinking is good enough.
Brian – your thoughts on the professor’s presentation are pretty interesting. On the surface it does seem appropriate to ask whether something is sustainable if it requires grant support. But if said scientist manages to sustain a hog operation, but can’t afford to tell anyone about it – what have we gained? If a tree falls in the forest… [said prof may have teaching responsibilities, might be on a tenure tread wheel where he’s evaluated on his ability to attract extramural funding, a list can grow (hmmm are such lists sustainable…)] Perhaps I’m overthinking this.
I told a story recently about putting a bolt in a baler flywheel where a shear pin had been shorn. It worked to get finished bailing the field. Good enough for me. Dad found the workaround later and lectured his son about the reason shear pins are there in the first place (e.g., NOT good enough for him). For a teenage farm boy, finishing up a project was the whole thing. For a farmer looking to keep a bailer intact for the longer term, and teach his son another ‘fact of life’, the standard for ‘good enough’ is set a touch further down the scale. Context matters (I think).
Nice story Clem. There’s also the intermediate position – ‘good enough for now to get the job done’, a stance I often take. Though being a forgetful human, I find good enough for now easily segues into good enough, which then results in problems of the broken baler kind. So I guess context does matter. You’re right. And so was your dad.
I’ve got another question for my favourite blogging, farming, statistical, sustainability geek.
‘Can the old four field system feed the world?
Regards,
Tom
Interesting question Tom. I don’t really have the time to answer it properly just at the moment, but a few thoughts:
1. I’d baulk at trying to say if it could feed the world – I’m sure there are a lot of countries who’d rather not eat our turnips and dodgy beer. So I’d be inclined to narrow your question to can it feed England?
2. Likewise, I’m cautious about saying that a diet of bread, beer & turnips would properly ‘feed’ us in relation to our full nutritional requirements, though I guess it’d be a whole lot better than nothing.
3. Anyway, taking yields of wheat & barley of 20 bushels/acre from the early 1800s when the 4 course rotation was at its height, and assuming turnip yields were similar to cabbages (it was mostly the leaves that were eaten), and throwing in half a lamb carcase or so from the quarter acre of clover, applying that to our current 12.1 million hectares, calculating the calorific value and dividing it by the calorific needs of the population, I get that we could furnish just under 75% of our present calorific needs from the 4 course rotation applied to existing agricultural land at 1800s yields. Bearing in mind that present conventional cereal yields are more than 5 times greater than early 1800s yields (and present organic are maybe 4 times greater?), I think this suggests it’s probably not too difficult to feed ourselves if that’s what we want our agricultural land to do.
What, the whole world doesn’t want to live like the English? Surely some mistake. Warm beer, toast and turnips, what more could anyone want?
Thanks for the statistics, that’s useful.
I have been making mission trips to Haiti for over a decade now. Around 15 trips of 2-3 weeks each. I’ve delved deeply into the field of tropical agriculture. In the tropics especially, organic matter content and soil fertility are essentially the same thing. Chemical fertilizers all by themselves are largely ineffective. See especially the work of Roland Bunch including “Five Fertility Principles”, “Restoring the Soil”, and “Green Manure/Cover Crops: Soil Recuperation at Zero Cost”.