There is a sub-set of farmers who have been practicing a much more sustainable form of agriculture for decades and we are coming up on the50th anniversaryof it’s beginnings.
I want to start writing about this event early because many environmentally-conscious folk are not aware of this hugely significant “revolution” that has occurred in agriculture over the past half century. No, I’m not talking about “Organic Farming.” That movement is about a decade older in the US and has had a much smaller impact. I’m talking about“No-till”专注于减少耕作所需的“耕作”或“耕作”量的农业和变体。
For many centuries, plowing and tillage have been key practices for agriculture.
That was how a good “seedbed” was prepared and that was how weeds were controlled. But just because a practice is ancient does not mean it is good. Plowed land is much more subject to water and winderosionand plowing combined with annual cropping has lead to the depletion ofcarbon stores in our soils.
History of No-till
In 1943, Edward Faulkner wrote a book titled “The Plowman’s Folly他对耕作的原因提出了质疑。这在当时是一个非常有争议的想法,但到了1960年,研究人员开始试图找到一种不破坏土壤的耕作方法。作物“残渣”被切碎后留在土壤表面。下一茬作物被“钻”到这个矩阵中。杂草的控制不是通过机械破坏土壤,而是通过使用除草剂(是的,有安全和环保的方法来做到这一点)。Between the work of USDA and University scientists,progressive growersand equipment and chemical companies, this concept was turned into an economically viable option that has now been adopted on around 66 million acres of US cropland (20% of the total) and on 260 million acres world-wide (excellent but fairly largeslide setabout this from no-till experts Rolf Derpsch and Theodor Friedrich). This system has proven to have the followingadvantages:
- Water and wind erosion diminished to near zero (with the added benefit of reduced fertilizer and pesticide residue movement that was associated with that soil movement)
- Reduced fuel use and the greenhouse gas emissions associated with it (e.g.66% reduction in corn)
- Labor efficiency (e.g. an individual grower can plant more acres or can reduce labor expense)
- Improvements in soil quality in terms of aggregate stability, rainfall capture efficiency (less runoff) and water holding capacity
- Increased soil carbon (particularly if paired with“cover-cropping”) that can “sequester” carbon dioxide from the atmosphere
- Increased biodiversity both above and below ground (e.g.earthworms)
- Better plant association withmycorrhizae(soil fungi which help plants obtain nutrients)
- Lower nitrous oxide emissionson most soils (a potent greenhouse gas)
No-till and other “Conservation tillage” systems combined with cover-cropping is the most sustainable option for agriculture today. Organic producers (who are more likely to practicecover cropping, to their credit) don’t really have the option of reduced tillage. There are some efforts in thatdirection, but they are not practical on any significant scale. Organic has been focused on buildingsoil organic carbonand that is an excellent thing to do, but part of the way they do it, importing large quantities of compost or manure, is problematic from a greenhouse gas perspective as I described in aprevious post. Reduced tillage and cover cropping is much more like the way that soils are built in a natural system.
So in the spring of 2010 those of us who are focused on sustainable agriculture will celebrate the work that was started a half century ago. Maybe a new market of carbon off-sets will help spur even more conversion.
No-till Soybeans Image from NRCS. Traditional plowing image from IRRI.
jonassays
但是,在你的免耕方法中,你使用化学品、杀虫剂、草药或类似的东西吗?
calicosays
The only farmers in my region (Maryland) that practice no-till on any scale that matters are those who are dependent on Round Up. Round Up (glyphosate) is Monsanto’s wide-spectrum herbicide which isn’t as biodegradable as they claimed. And in order to use it, the farmers MUST buy genetically-modified (GM) crops (“Round Up Ready”) which not only introduces unlabeled GM to the food supply, it ties farmers to an lifetime of buying seed each year from the Monsanto corporation. Monsanto prohibits the sustainable practice of reusing seed, and they’ve sued and bankrupted some farmers who were supposedly growing Monsanto seed without paying to plant it. Trouble is the GM seed is permitted on open-pollinated varieties. So even if you’ve never bought from Monsanto, if your neighbor did, you may have your crop contaminated (and you will be sued). NOT sustainable at all !!!