Η συμβατική γεωργία , γνωστή και ως παραδοσιακή γεωργία ή βιομηχανική γεωργία , αναφέρεται σε συστήματα γεωργίας που περιλαμβάνουν τη χρήση συνθετικών χημικών λιπασμάτων , φυτοφαρμάκων , ζιζανιοκτόνων και άλλων συνεχών εισροών, γενετικά τροποποιημένων οργανισμών , συμπυκνωμένων εργασιών διατροφής ζώων, βαριά άρδευση , εντατική άροση , ή συμπυκνωμένη μονοκαλλιέργειαπαραγωγή. Έτσι, η συμβατική γεωργία είναι συνήθως πολύ απαιτητική από πόρους και ένταση ενέργειας, αλλά και εξαιρετικά παραγωγική. Παρά το όνομά του, οι συμβατικές γεωργικές μέθοδοι αναπτύχθηκαν μόνο από τα τέλη του δέκατου ένατου αιώνα και δεν έγιναν ευρέως διαδεδομένες μόνο μετά τον Β' Παγκόσμιο Πόλεμο (βλ.: Wikipedia:Green Revolution .

Η συμβατική γεωργία συνήθως έρχεται σε αντίθεση με τη βιολογική γεωργία (ή μερικές φορές τη βιώσιμη γεωργία ή την περμακαλλιέργεια ), καθώς αυτές ανταποκρίνονται σε συγκεκριμένες συνθήκες τοποθεσίας ενσωματώνοντας πολιτιστικές, βιολογικές και μηχανικές πρακτικές που προάγουν την ανακύκλωση των πόρων, προάγουν την οικολογική ισορροπία και διατηρούν τη βιοποικιλότητα. [1] Αντί να χρησιμοποιούν συνθετικά λιπάσματα, φυτοφάρμακα, ρυθμιστές ανάπτυξης και πρόσθετα ζωοτροφών, τα συστήματα βιολογικής γεωργίας βασίζονται στην αμειψισπορά, στην κοπριά ζώων και φυτών ως λιπάσματα, σε κάποιο χειροκίνητο βοτάνισμα και βιολογικό έλεγχο παρασίτων. [2] Ορισμένες συμβατικές γεωργικές δραστηριότητες μπορεί να περιλαμβάνουν περιορισμένη πολυκαλλιέργεια ή κάποια μορφή ολοκληρωμένης διαχείρισης παρασίτων. (Βλέπε: Βιομηχανική βιολογική γεωργία ).

Συμβατική έναντι βιολογικής γεωργίας

Πλεονεκτήματα και μειονεκτήματα

Οποιαδήποτε νέα τεχνολογία θα έχει θετικές και αρνητικές συνέπειες. Αν αναλύσουμε τις θετικές και τις αρνητικές πτυχές του τρόπου με τον οποίο παράγουμε τρόφιμα, ίσως θα μπορέσουμε να βελτιώσουμε τα καλά πράγματα και να μειώσουμε τις αρνητικές επιπτώσεις. Με τη συμβατική γεωργία είναι δυνατό να παραχθούν πολύ μεγαλύτερες ποσότητες τροφίμων, σε λιγότερη γη και με λιγότερη χειρωνακτική εργασία από ποτέ στην ιστορία.

Με το αυξανόμενο κόστος των τροφίμων και τα εκατομμύρια ανθρώπων να λιμοκτονούν σε όλο τον κόσμο, φαίνεται ότι έχουμε ηθική υποχρέωση να χρησιμοποιούμε συμβατικές μεθόδους για να παράγουμε μεγάλες ποσότητες τροφίμων σε προσιτές τιμές. Ωστόσο, επειδή πολλές από τις επιπτώσεις της συμβατικής γεωργίας είναι άγνωστες και λόγω του πόσες από τις επιπτώσεις μπορεί να είναι μη αναστρέψιμες και επιβλαβείς, μπορεί να είναι ασφαλέστερο να παραμείνουμε σε αυτό που κάνουμε εδώ και εκατοντάδες χρόνια . Μπορεί να θεωρηθεί ανεύθυνο να συνεχίσουμε να χρησιμοποιούμε φυτοφάρμακα, ακτινοβολίες και ΓΤΟ όταν πραγματικά δεν γνωρίζουμε ποιες είναι οι παρενέργειες.

Οικολογία

Υπάρχει μια κοινή αντίληψη ότι η βιολογική γεωργία είναι πιο οικολογικά βιώσιμη από τη συμβατική. Ως αποτέλεσμα των συνθηκών βιομηχανικής καλλιέργειας, οι σημερινές αυξανόμενες περιβαλλοντικές πιέσεις επιδεινώνονται περαιτέρω, όπως:

Υπάρχουν πολλοί παράγοντες στο πόσο βιώσιμες είναι οι γεωργικές πρακτικές, εκτός από τη χρήση τεχνητών χημικών. Π.χ:

Ανθρώπινη υγεία

Τα βιολογικά τρόφιμα συνήθως θεωρείται ότι είναι πιο υγιεινά από τα συμβατικά τρόφιμα. Εκατοντάδες μελέτες έχουν προσπαθήσει να αξιολογήσουν εάν τα συμβατικά παραγόμενα τρόφιμα έχουν διαφορετικές επιπτώσεις στην υγεία από εκείνα που παράγονται βιολογικά. Τα τελευταία χρόνια μερικές μετα-μελέτες έχουν καταλήξει σε διαφορετικά συμπεράσματα με βάση αυτές τις προηγούμενες μελέτες. Μια μετα-μελέτη 237 μελετών που διεξήχθη στο Στάνφορντ καταλήγει στο συμπέρασμα ότι «Δεν υπάρχει μεγάλη διαφορά μεταξύ των βιολογικών και των συμβατικών τροφίμων, αν είσαι ενήλικας και λαμβάνεις μια απόφαση βασισμένη αποκλειστικά στην υγεία σου». [4] Μια άλλη μετα-μελέτη από ερευνητές στο Πανεπιστήμιο του Νιούκαστλ με βάση 343 προηγούμενες μελέτες διαπίστωσε ότι οι συμβατικά παραγόμενες καλλιέργειες περιείχαν 18-69% λιγότερα αντιοξειδωτικά, were four times as likely to contain pesticide residues, and had, on average 48% higher concentrations of heavy metals (including cadmium) than organically-produced crops.[5]

Potential conflicts of interest have been identified in both of these cases, as the institutions involved with these studies have received funding from agriculture business interests in both the conventional and organic sectors.

Many supporters of organic agriculture rely on personal experiences and beliefs when choosing organic over conventionally produced food. "Although, as scientists, we may deplore the fact that people are swayed by non-scientific views, the fact is that a lot of them are. Despite the arguments presented by Trewavas, many people believe that organic production systems produce better food, care more for animal welfare and are kinder to the environment,".[6]

Yield

It is generally recognized that conventional farming produces a higher amount of food than organic. One meta-study found organic yields to be on average 80% that of conventional, but "the organic yield gap significantly differed between crop groups and regions.".[7] Another meta-analysis concluded that, "organic yields are typically lower than conventional yields. But these yield differences are highly contextual, depending on system and site characteristics, and range from 5% lower organic yields (rain-fed legumes and perennials on weak-acidic to weak-alkaline soils), 13% lower yields (when best organic practices are used), to 34% lower yields (when the conventional and organic systems are most comparable)."[8]

Modern farmland is claimed to produce 200 percent more wheat than the same area did 70 years ago. Hence switching to organic farming would lead to a reduction in output, e.g. by 20% for corn.[9] The figure is plausible, but we need more than one unattributed figure.[10]

Biodiversity

Several studies have compared the local biodiversity of conventional and organic systems. A meta-study at the Swedish University of Agricultural Sciences concluded,

"Organic farming usually increases species richness, having on average 30% higher species richness than conventional farming systems. However, the results were variable among studies, and 16% of them actually showed a negative effect of organic farming on species richness. [...] Birds, insects, and plants usually showed an increased species richness in organic farming systems. However, the number of studies was low in most organism groups (range 2–19) and there was significant heterogeneity between studies. [...] On average, organisms were 50% more abundant in organic farming systems, but the results were highly variable between studies and organism groups. Birds, predatory insects, soil organisms and plants responded positively to organic farming, while non-predatory insects and pests did not. The positive effects of organic farming on abundance were prominent at the plot and field scales, but not for farms in matched landscapes.[11]

A study at the University of Bristol comparing 10 conventional and 10 organic agricultural landscapes found that although the organic farms had a greater amount of non-cultivated or "semi-natural" areas, they did not have higher biodiversity in those spaces. However, there was greater biodiversity in the organic farms' arable fields.[12]

There is a common concern that links yield (see above) and biodiversity. The assumption is that if organic agriculture has lower yields, this will increase the need for more areas under cultivation, and hence have a negative impact on region- or world-wide biodiversity. It is unclear whether any studies have been done to test this assumption.

Social and economic aspects

A study regarding agricultural knowledge distribution from Cardiff University found that, "the conventional food chain [...] tends to distribute knowledge towards input suppliers, and the organic food supply chain [...] distributes knowledge back towards the farm," due to their differing economic features.[13]

Pesticides

Pesticides are substances used to kill insects, plants and other organisms that negatively impact crop yield. They can range from hazardous, artificially-isolated chemicals, such as many organochlorides, to relatively innocuous plant-based preparations, like neem oil. Pesticides can have unintended consequences such as killing off beneficial, predatory insects.

Most of the pesticides in our food, by far, are natural pesticides produced by the plants. This leaves open the question of whether the artificial chemicals are worse for us. After all, not all substances are the same, and some (such as DDT) linger in the environment for far longer. It's also true that something is harmful given to lab rats in large quantities, yet not significantly harmful in small quantities - or even beneficial, since there has been research suggesting that toxins in small doses actually benefit an organism by making it react to the mild stress.[verification needed]

Many natural chemical compounds are also toxic or carcinogenic in large quantities, but we consume them in small quantities. Everything has a toxic dose - even water, salt or any nutrient.

There is a common perception that "the poisons are killing us." So why are we living longer than ever? If there is a negative effect from these traces of chemicals, the effect is much smaller than positive changes in modern times (e.g. better medicines and medical treatments).

Note that these arguments are not saying that "pesticides are good for you" - using them inappropriately, without following directions, has the potential to be very harmful. But when used properly, they appear to not be significantly harmful, and may not be harmful at all. Worrying about them may do us more harm than the chemicals themselves.

Read more

Fertilizers

Fertilisers are substances that can be supplied to the soil so as to improve the soil quality and promote the growth of any plants grown in this soil. Fertilisers come in several types and correct application differs depending on this type. Differences on application may include: method of introducing the fertiliser into the soil, the time of the year when the fertiliser is administered, etc...

There's actually little doubt that fertilizers harm ecosystems. But is this inevitable, and what are the alternatives? Limited use and precise application reduce the effect of eutrophication on waterways. More recent discoveries, e.g. the role of soil fungi, the impact of compost teas, and terra preta, show that there may be much greener ways to create abundance in food production.[verification needed] However, this knowledge is still in its early years - the knowledge is still being developed, and the valuable knowledge that already exists has not yet spread widely.

Read more

Nitrogen sources

Borlaug said:[10]

Even if you could use all the organic material that you have--the animal manures, the human waste, the plant residues--and get them back on the soil, you couldn't feed more than 4 billion people (and) you would have to increase cropland area dramatically...

At the present time, approximately 80 million tons of nitrogen nutrients are utilized each year. If you tried to produce this nitrogen organically, you would require an additional 5 or 6 billion head of cattle to supply the manure.

This appears to not consider the impact of nitrogen fixation,W for example by legume crops. (This is another argument for vegetarianism and veganism being greener - less methane-producing cows, and more legume crops to replace them, which will also produce nitrogen.)

Currently, enormous amounts of nutrients are thrown away in our sewage. Through humanure this can be salvaged, but may not be suitable for many food crops, especially where the food is close to the ground.

GMOs

Genetically modified apple

A genetically modified organism (GMO) is an organism whose genetic material has been altered using genetic engineering techniques. Genetic engineering essentially involves incorporation of gene(s) from an different species - even across Kingdom - into the host genome. Thus, genes from animals and bacteria may be inserted into a plant genome, to create a novel transgenic plant. Transgenic breeding is thus different from the traditional selective breeding, and therefore novel gene products (like proteins) from the GMO may have some unexpected environmental effects.

Several antibodies and medicines have already been commercially produced by using genetic engineering. For example, mammalian insulin is being produced by recombinant DNA in bacteria. This make the hormone much cheaper than natural insulin derived from conventional biosynthesis. However, when genetic engineering is applied in agriculture for production of crops, there are many uncertainties and risks.

Unlike insulin or other GM drugs and hormones manufactured in the laboratory, GM crops cannot be controlled or revoked, once they are released in nature.[14] In addition to the possible harmful effects on ecosystems (including agro-ecosystems), introduction of the GMOs into the human food chain poses an unprecedented risk to public health.

Genetically modified food has caused considerable controversy since the early 1990s, when it was first introduced. However, this controversy only relates to GM organisms that have been created using the transgenesis method. Cisgenesis has been proven equally safe as regular plant breeding by the EFSA[15]

Conventional food production often utilizes GMO's which are different from plants and animals that have been selectively bred. There are environmental drawbacks of using GMOs. One is that it is difficult to control the reproduction of plants, especially when they are growing in an open environment, and not contained within a structure such as a greenhouse. When there is a farm with GMOs nearby another farm, there can be a problem with crossbreeding between the two varieties of plant. This can result in genetic drift which can have negative impacts on farms that produce heirloom varieties. When this effect is coupled with the terminator gene (a gene inserted in plants by companies that produce GMO's, which prevents their seeds from producing viable offspring) this can have devastating effects on heirloom varieties, and for farmers who have been keeping their variety for generations.

Read more

References

  1. Definition according to the USDA
  2. "Nutritional quality of organic food: shades of grey or shades of green?", Christine Williams Proceedings of the Nutrition Society 2002
  3. Brown, Lester R. Plan B 4.0: Mobilizing to Save Civilization. W.W. Norton, 2009.
  4. http://med.stanford.edu/news/all-news/2012/09/little-evidence-of-health-benefits-from-organic-foods-study-finds.html
  5. http://research.ncl.ac.uk/nefg/QOF/crops/page.php?page=1
  6. "Organic movement reveals a shift in the social position of science" Annette Mørkeberg & John R. Porter Nature Number 412, page 677, August 2001
  7. Tomek de Ponti, Bert Rijk, Martin K. van Ittersum, "The crop yield gap between organic and conventional agriculture" in Agricultural Systems 108 (2012) 1–9
  8. Verena Seufert , Navin Ramankutty, Jonathan A. Foley, "Comparing the yields of organic and conventional agriculture," in Nature 485 (10 May 2012) 229-234
  9. Exposing the organic myth, BusinessWeek.com (msnbc.com). (The claim about the 200% increase for wheat is made on page 2).
  10. Άλμα πάνω, στο: 10.0 10.1 Billions Served: Norman Borlaug interviewed by Ronald Bailey, April 2000, on Reason.org - this is a consistently skeptical and conservative site, including against mainstream science, so it needs to be checked for bias and selective reporting; however BorlaugW is a Nobel laureate and an influential scientist, so his interview is certainly notable."
  11. Janne Bengtsson, Johan Ahnström, Ann-Christin Weibull, "The effects of organic agriculture on biodiversity and abundance: a meta-analysis" in Journal of Applied Ecology 42 (2005) 261–269
  12. RH Gibson, S. Pearce, RJ Morris, WOC Symondson, J. Memmott, "Plant diversity and land use under organic and conventional agriculture: a whole-farm προσέγγιση" στο Journal of Applied Ecology 44 (2007) 792–803
  13. Kevin Morgan, Jonathan Murdoch, "Organic vs. συμβατική γεωργία: γνώση, δύναμη και καινοτομία στην τροφική αλυσίδα", στο Geoforum 31 (2000) 159-173
  14. Paul, John (2018) Genetically Modified Organisms (GMOs) as Invasive Species , Journal of Environment Protection and Sustainable Development. 4 (3): 31–37.
  15. Περιοδικό Kijk 10/2012
Δεδομένα σελίδας
Λέξεις-κλειδιάγεωργία , γεωργία , τρόφιμα , λιπάσματα , καλλιέργειες τροφίμων , βιολογική γεωργία , έλεγχος παρασίτων
SDGSustainable Development GoalSDG02 Μηδενική πείνα
ΣυγγραφείςΊθαν , Κρις Γουότκινς
Δημοσίευσε2009
ΑδειαCC-BY-SA-4.0
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