Flame Weeding & Vergilian Weed Management
Flame weeding is pretty much what it sounds like: you strap a propane tank to your back and use what is essentially a flame thrower to kill the weeds sprouting in a bed. It brings an element of Mad Max: Fury Road to what is otherwise a rather pacific morning--planting and weeding.
While the technology has certainly changed, the practice has its roots (pun intended) in ancient agriculture. In the Georgics, Vergil recommends:
saepe etiam sterilis incendere profuit agros
atque levem stipulam crepitantibus urere flammis:
sive inde occultas viris et pabula terrae
pinguia concipiunt, sive illis omne per ignem
excoquitur vitium atque exsudat inutilis umor,
seu pluris calor ille vias et caeca relaxat
spiramenta, novas veniat qua sucus in herbas,
seu durat magis et venas astringit hiantis,
ne tenues pluviae rapidive potentia solis
acrior aut Boreae penetrabile frigus adurat.
multum adeo, rastris glaebas qui frangit inertis
vimineasque trahit cratis, juvat arva, neque illum
flava Ceres alto nequiquam spectat Olympo;
et qui, proscisso quae suscitat aequore terga,
rursus in obliquum verso perrumpit aratro
exercetque frequens tellurem atque imperat arvis.
It's often profitable to inflame the sterile fields
and to burn the light stubble with crackling flames:
whether because from that the earth finds
hidden strength and rich food or every flaw in her
is cooked out through fire and the useless moisture sweats out,
or maybe that heat releases paths and hidden
vents by which sap comes into the new grass,
or maybe hardens them and tightening the gaping veins,
lest scanty rains and the swift sun's strength
or the North's piercing cold more bitterly burn.
And he who breaks the lifeless glebe with hoes
and drags wickerwork over it pleases the fields very much,
nor does flaxen Ceres in vain from lofty Olympus;
and he who breaks the furrows which he's raised from
cloven field by turning his plough back at an angle
and often works the ground governs the fields.
(Georgics I.84-99)
Vergil's advice comes in his section on soil emendation. His humility in not proclaiming one definitive reason why a particular practice is beneficial is, I think, one of the charms of Vergil's Georgics. Observationally, burning is known to improve a field's health but what precisely is going on to make that happen is unclear.
As organic farmers, we can't really use herbicides. This leaves us with a few options. One of the more popular ones is plastic mulch. Mulch here has little in common with the brown, pungent wood chips spread over gardens and pathways across the country. Rather, it is large sheets of plastic stretched over a bed with holes punched in it through which the desired crop grows. The plastic shades out the weeds and helps hold in moisture and warmth. It is highly effective. However, it creates a lot of waste (you can't reuse it) and begs the question: how sustainable is organic farming when it relies heavily upon plastics? Would spraying herbicides sparingly actually be better for the earth? Another option is hand-weeding. With certain crops, this means getting down on your hands and knees and manually pulling out weeds. This is labor-intensive and time-consuming. Economically, it can be unsustainable. Other crops can be weeded more efficiently with tools (drag that hoe through the bed!). Flame-weeding is a third option, and is probably best used as a preventative measure. After harrowing a field, which uproots and kills any plants growing in it, it's not a bad idea to leave it fallow for a few days giving the seeds in the seed bank (the collection of seeds lying dormant in the soil), which have just been brought to the surface by the harrow, time to germinate. Once they've sprouted, you can go through with a flame weeder killing the new weeds without disturbing the soil and bringing new seeds to the surface. This is not a bad idea if you're hoping to plant a slow-growing crop like carrots that is easily out-competed by weeds.
Interestingly enough, this third option for organic weed-management is closest to Vergil's advice. In the passage quoted above, Vergil first recommends burning, then hoeing and dragging wickerwork over the field. Wickerwork, in the ancient world, was used as a harrow. After harrowing it, Vergil advises going over the field twice with a plow. At first in straight lines, and then again at an angle to the original furrow. One can assume that the initial burning of the field would kill any weeds growing and hopefully get hot enough to damage weed seeds in the soil. The harrowing and double ploughing would then mix the burned organic material from the stubble and weeds into the field, thereby enriching it, and break apart any large clumps of soil, thereby creating a soft bed for sowing.
In conclusion, Vergil's advice on preparing a field is 10/10 still good advice. The next time someone asks me why I study Classics, I'm saying, "because it's right, dammit."
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| Basically what organic farming looks like. No joke. Image from: http://www.nydailynews.com/entertainment/movies/zoe-kravitz-wives-mad-max-fury-road-article-1.2213982 |
saepe etiam sterilis incendere profuit agros
atque levem stipulam crepitantibus urere flammis:
sive inde occultas viris et pabula terrae
pinguia concipiunt, sive illis omne per ignem
excoquitur vitium atque exsudat inutilis umor,
seu pluris calor ille vias et caeca relaxat
spiramenta, novas veniat qua sucus in herbas,
seu durat magis et venas astringit hiantis,
ne tenues pluviae rapidive potentia solis
acrior aut Boreae penetrabile frigus adurat.
multum adeo, rastris glaebas qui frangit inertis
vimineasque trahit cratis, juvat arva, neque illum
flava Ceres alto nequiquam spectat Olympo;
et qui, proscisso quae suscitat aequore terga,
rursus in obliquum verso perrumpit aratro
exercetque frequens tellurem atque imperat arvis.
It's often profitable to inflame the sterile fields
and to burn the light stubble with crackling flames:
whether because from that the earth finds
hidden strength and rich food or every flaw in her
is cooked out through fire and the useless moisture sweats out,
or maybe that heat releases paths and hidden
vents by which sap comes into the new grass,
or maybe hardens them and tightening the gaping veins,
lest scanty rains and the swift sun's strength
or the North's piercing cold more bitterly burn.
And he who breaks the lifeless glebe with hoes
and drags wickerwork over it pleases the fields very much,
nor does flaxen Ceres in vain from lofty Olympus;
and he who breaks the furrows which he's raised from
cloven field by turning his plough back at an angle
and often works the ground governs the fields.
(Georgics I.84-99)
Vergil's advice comes in his section on soil emendation. His humility in not proclaiming one definitive reason why a particular practice is beneficial is, I think, one of the charms of Vergil's Georgics. Observationally, burning is known to improve a field's health but what precisely is going on to make that happen is unclear.
As organic farmers, we can't really use herbicides. This leaves us with a few options. One of the more popular ones is plastic mulch. Mulch here has little in common with the brown, pungent wood chips spread over gardens and pathways across the country. Rather, it is large sheets of plastic stretched over a bed with holes punched in it through which the desired crop grows. The plastic shades out the weeds and helps hold in moisture and warmth. It is highly effective. However, it creates a lot of waste (you can't reuse it) and begs the question: how sustainable is organic farming when it relies heavily upon plastics? Would spraying herbicides sparingly actually be better for the earth? Another option is hand-weeding. With certain crops, this means getting down on your hands and knees and manually pulling out weeds. This is labor-intensive and time-consuming. Economically, it can be unsustainable. Other crops can be weeded more efficiently with tools (drag that hoe through the bed!). Flame-weeding is a third option, and is probably best used as a preventative measure. After harrowing a field, which uproots and kills any plants growing in it, it's not a bad idea to leave it fallow for a few days giving the seeds in the seed bank (the collection of seeds lying dormant in the soil), which have just been brought to the surface by the harrow, time to germinate. Once they've sprouted, you can go through with a flame weeder killing the new weeds without disturbing the soil and bringing new seeds to the surface. This is not a bad idea if you're hoping to plant a slow-growing crop like carrots that is easily out-competed by weeds.
Interestingly enough, this third option for organic weed-management is closest to Vergil's advice. In the passage quoted above, Vergil first recommends burning, then hoeing and dragging wickerwork over the field. Wickerwork, in the ancient world, was used as a harrow. After harrowing it, Vergil advises going over the field twice with a plow. At first in straight lines, and then again at an angle to the original furrow. One can assume that the initial burning of the field would kill any weeds growing and hopefully get hot enough to damage weed seeds in the soil. The harrowing and double ploughing would then mix the burned organic material from the stubble and weeds into the field, thereby enriching it, and break apart any large clumps of soil, thereby creating a soft bed for sowing.
In conclusion, Vergil's advice on preparing a field is 10/10 still good advice. The next time someone asks me why I study Classics, I'm saying, "because it's right, dammit."
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