科學家揭露草甘膦毒害農作物和土壤

            遺傳修飾（轉基因）崩潰續

科學家們繼續向公眾制造由抗草甘膦作物產生的對生態系統造成毀滅性的影響，而美國農業部保持沉默。侯美婉博士

此網站上的資料未經明確允許不得以任何形式復制。申請許可并復制，請聯系ISIS。在許可被批準后，所有鏈接必須保持不變。

世界最廣泛使用的除草劑造成的可怕后果

抗草甘膦（GT）農作物自1996年美國推出以來，已經在世界各地迅速傳播，現在種植面積占全球轉基因（GM）農作物種植面積的85% [1]。同時，草甘膦（商品名農達）被作為對健康和環境安全的除草劑而推廣使用，成為世界上最廣泛使用的除草劑。

但抗草甘膦作物對生態和健康的不利影響迅速曝光，并且多年來不斷惡化而監管層視而不見（見[2, 3] Roundup Ready Sudden Death, Superweeds, Allergens..., SiS 28; Ban Glyphosate Herbicides Now, SiS 43）。

草甘膦結合烯醇丙酮酸莽草酸-3-磷酸合酶（EPSPS）并使其失活，烯醇丙酮酸莽草酸-3-磷酸合酶是植物莽草酸合成途徑中的關鍵酶，是合成芳香族氨基酸所必需的，包括必需氨基酸苯丙氨酸，色氨酸和酪氨酸，以及下游產物諸如植物生長促進劑——吲哚乙酸和植物防御化合物——植物抗毒素[4]。但草甘膦具有許多副作用，對作物健康和產量的增效作用，遠遠超出了工廠排入土壤生態系統和更廣泛的環境的不利影響。

抗草甘膦（GT）性狀依賴于GT引入了土壤農桿菌的EPSPS，它對草甘膦不敏感，因此草甘膦被抗草甘膦作物吸收并被轉運至根和莖的生長部分，甚至從根際（根系周圍的土壤）滲出，因此它會影響到土壤中的微生物群落以及隨后種植在該土壤中的農作物。

兩名美國高級科學家，十年來在一直研究草甘膦的生態影響和“農達”作物生態系統。他們警告： “可怕的農業后果，如土壤貧瘠，農作物非生產性和植物營養不足。”

草甘膦——誘發植物疾病和毒素的一個最重要的因素

最近從美國普渡大學退休的Don Huber，與合著者G.S. Johal——就職于普渡大學的植物學和植物病理學系，2009年10月在《歐洲農學雜志》上發表的一篇論文指出，草甘膦在美國廣泛使用能“大大增加各種植物疾病的嚴重程度，損害植物防御病原體和疾病的體系，并且固定不動的土壤和植物養分使它們無法被植物利用。”

此外，草甘膦刺激真菌生長并增強病原體的毒性，如鐮刀霉， “可對一個范圍廣泛的敏感作物可持續生產造成嚴重后果。”他們警告說，“忽略潛在的非目標的任何化學品的有害副作用，特別是如草甘膦的嚴重使用，有可能對農業造成可怕后果如土壤貧瘠，作物非生產性，植物營養不足。“

在《有機及非轉基因生物報告》的一次采訪中[5]，Huber說，他已經研究了草甘膦20年，當他發現小麥真菌疾病持續上升時，開始注意到草甘膦的使用問題，當時草甘膦早些年已被應用于控制雜草。他發現草甘膦會使植物中錳含量減少，錳是許多植物對疾病和環境壓力的防御反應所必需的。草甘膦固定植物的營養成分，如錳，銅，鉀鐵，鎂，鈣和鋅，因此，他們不再具備營養功能。基本上，草甘膦完全削弱了植物，使其容易受到土壤傳播的真菌病原體的感染。 “這就是為什么我們看到植物疾病在增加的原因，”他說。

在過去的15至18年里有一些植物疾病呈現增長趨勢。四種主要的土壤真菌，鐮刀霉，腐霉，絲核菌和疫霉，在使用草甘膦后更具活力；并且，這些真菌引起的疾病增加，如玉米赤霉病，或大豆爛根，甜菜冠腐病。赤霉病，影響谷類作物，產生的毒枝菌素，會進入食物鏈。

有超過40種疾病被報告在使用草甘膦后發生，而且數目隨著人們的認識而不斷增加，Huber說。

當被問及草甘膦是否如支持者所宣稱德那樣對”環境友好”，他回答：“絕對不會。那是徹頭徹尾的錯誤概念。草甘膦是誘發植物疾病和植物毒素的最重要農藝因素。這些毒素對動物和人類健康造成嚴重影響。”

 “產生的毒素能夠感染植物根部和頂部，并轉移到植物的其余部位。” Huber解釋道。 “秸稈的毒素水平可以高到足以使牛和豬不育。”

草甘膦影響人體健康的一個途徑是“微量元素如錳，銅，鉀，鐵，鎂，鈣和鋅，是人體必不可少的。他們都可被草甘膦而減少利用率，所以草甘膦處理GT植物及其他暴露于草甘膦的植物礦質營養較少。 “我們看到在我們的食物營養品質減少。”

“在[農達]基因會減少微量營養素鋅和錳含量高達百分之五十的...這也說明了報道的抗草甘膦大豆產量滯后的原因。”

“不幸的是，大多數研究人員都不得在該領域做工作。他們沒有獲得同基因系的途徑[常規和抗草甘膦株系在其他遺傳方面完全相同的]，這些材料拒絕提供給研究人員。“

Huber和Johal勸告使用盡可能少的草甘膦。

不幸的是，降低了草甘膦劑量，不足以殺死雜草，尤其是眾多的雜草正在變成高抗除草劑的雜草（見[6] GM Crops Facing Meltdown in the USA, SiS 46)

抗草甘膦系統改變了整個土壤生物學

Robert Kreme是USDA-ARS（美國農業部農業研究服務部）微生物學家，并且是密蘇里大學植物科學部兼職教授。他從1997年開始研究新孟山都公司抗草甘膦系統（農達除草劑和GT種植）如何改變大豆線蟲的水平。他的研究小組開始在根部尋找，看到根部的微生物群落，并懷疑是草甘膦產生了影響。似乎是根部真菌的問題導致猝死綜合癥。

事實上，該系統 “改變了整個土壤生物學。” Kremer告訴《有機及非轉基因生物報告》[7]。 "我們看到植物根部細菌的不同和養分供應的改變。許多研究表明，草甘膦對[一些]微生物有毒性作用，能刺激[其他一些]微生物孢子萌發，在植物根部生成菌落。其他研究人員顯示，草甘膦可固定錳，一種重要的植物微量營養素。"

草甘膦對益菌如固氮菌——根瘤菌有毒，但會增加病原微生物如鐮刀霉的發生。 “有些甚至不使用草甘膦的抗草甘膦品種，往往更容易被鐮刀霉感染，”可能是基因改造意想不到的效果。

如果土壤充滿磷酸鹽（當禽畜糞便作為肥料使用），草甘膦會滲入地下水（毒害其他野生動植物物和人類）。

“我們看到了農達生態系統中這些真菌在增加，包括大豆和玉米。” Kremer說。

這些論文描述了他的研究小組的工作，在《歐洲農學雜志》上發表[8]沒有被美國接收。Kremer說，[7]："我正在在USDA-ARS工作，對這些研究要發表新聞稿。我極力向管理員推薦，但他們不愿意把一些東西公開。他們的想法是，如果農民使用該（草甘膦）技術，美國農業部并不希望關于它的負面信息被釋放。這是怎樣的。我認為要發布的新聞仍然放在某人的辦公桌上。"

Kremer作出結論[7]："我們正在尋找一些方法可用于克服負面影響，如果我們繼續使用農達作物，如葉面噴施營養補充物”但他補充說，“我對可持續農業更感興趣。更多的農民對利用覆蓋種植，以保持土壤質量和其他有機修正感興趣。但對他們來說是一個曲折的學習過程。"

Scientists Reveal Glyphosate Poisons Crops and Soil

GM Meltdown Continues

Scientists go public on devastating ecological impacts of Roundup Ready cropping systems while USDA keeps mum Dr. Mae-Wan Ho

MATERIAL ON THIS SITE MAY NOT BE REPRODUCED IN ANY FORM WITHOUT EXPLICIT PERMISSION. FOR PERMISSION, AND REPRODUCTION REQUIREMENTS, PLEASE CONTACT ISIS. WHERE PERMISSION IS GRANTED ALL LINKS MUST REMAIN UNCHANGED

Dire consequences from the most widely used herbicide in the world

Glyphosate-tolerant (GT) crops have spread rapidly around the world since they were introduced in the US in 1996, and are now planted on 85 percent of the global area growing genetically modified (GM) crops [1]. Concomitantly, glyphosate (commercial formulation Roundup), promoted as safe for health and the environment, became the most widely used herbicide in the world.

But ecological and health impacts of the GT cropping system soon came to light, and have been worsening relentlessly over the years while regulators turn a blind eye (see [2, 3] Roundup Ready Sudden Death, Superweeds, Allergens..., SiS 28; Ban Glyphosate Herbicides Now, SiS 43).

Glyphosate binds with and inactivates EPSPS, the critical enzyme in the shikimate pathway required for the synthesis of aromatic plant metabolites including essential amino acids phenylalanine, tryptophan and tyrosine, as well as downstream products such as plant growth promoter, indoylacetic acid and plant defence compounds, phytoalexins [4]. But glyphosate has multiple adverse effects that act synergistically on crop health and productivity that extends well beyond the plant into the soil ecosystem and the wider environment. 

The GT trait depends on incorporating an EPSPS from the soil bacterium Agrobacterium tumefaciens that is insensitive to glyphosate, hence glyphosate is taken up by GT plants and translocated to the growing parts of roots and shoots, and even exuded into the rhizosphere (soil surrounding the roots) so it can affect the soil community of microorganisms and also subsequent crops planted in the soil. Two senior scientists in the US who have been investigating the ecological impacts of glyphosate and the Roundup Ready cropping system for decades are warning of “dire consequences for agriculture such as rendering soils infertile, crops non-productive, and plants less nutritious.”

Glyphosate the single most important factor predisposing plants to diseases and toxins

Don Huber, recently retired from Purdue University, and co-author, at Purdue’s Dept of Botany and Plant Pathology, stated in a paper published in the October 2009 issue of European Journal of Agronomy that the widespread use of glyphosate in the US can “significantly increase the severity of various plants diseases, impair plant defense to pathogens and diseases, and immobilize soil and plant nutrients rendering them unavailable for plant use.”

Further, glyphosate stimulates the growth of fungi and enhances the virulence of pathogens such as Fusarium, and “can have serious consequences for sustainable production of a wide range of susceptible crops.” They warn that “Ignoring potential non-target detrimental side effects of any chemical, especially used as heavily as glyphosate, may have dire consequences for agriculture such as rendering soils infertile, crops non-productive, and plants less nutritious.”

In an interview [5] with the Organic & Non-GMO Report, Huber said he has been researching glyphosate for 20 years, and began noticing problems when he saw a consistent increase in “take-all”, a fungal disease of wheat, when glyphosate had been applied in a previous year to control weeds. He found glyphosate reduced manganese in plants, which is essential to many plant defence reactions against disease and environmental stress. Glyphosate can immobilize plant nutrients such as manganese, copper, potassium iron, magnesium, calcium, and zinc, so they are no longer nutritionally functional. Basically, glyphosate completely weakens the plant, making it susceptible to soil-borne fungal pathogens. “That is one reason why we see an increase in plant diseases,” he said.

There has been a general increase in the number of plant diseases in the past 15 to 18 years. Four primary soil fungi,  Fusarium, Phythium, Rhizoctonia, and Phytophthora, have become more active with the use of glyphosate; and concomitantly, diseases caused by these fungi have increased, such as head scab in corn, or root rot in soybeans, crown rot in sugar beets. Fusarium head blight, which affects cereal crops, is a disease that produces a mycotoxin that could enter the food chain.

There are more than 40 diseases reported with the use of glyphosate, and the number keeps growing as people recognize the association, Huber said.

When asked if glyphosate is “environmentally benign” as claimed by proponents, he answered “Absolutely not. That’s an outright mistaken notion. Glyphosate is the single most important agronomic factor predisposing some plants to both disease and toxins. These toxins can produce a serious impact on the health of animals and humans.

 “Toxins produced can infect the roots and head of the plant and be transferred to the rest of the plant.” Huber explained. “The toxin levels in straw can be high enough to make cattle and pigs infertile.”

One way in which glyphosate can affect human health is that “micronutrients such as manganese, copper, potassium, iron, magnesium, calcium, and zinc are essential to humans. All of them can be reduced in availability by glyphosate; so glyphosate treated GT plants as well as other plants exposed to glyphosate have less mineral nutrients. “We are seeing a reduction in nutrient quality [in our food].”

 “The [Roundup Ready] gene will reduce micronutrient efficiency up to 50 percent for zinc and manganese…This could also account for the yield drag [reported for GT soybeans].”

“Unfortunately, most researchers are forbidden to do work in the area. They don’t have access to isogenic lines [conventional and Roundup Ready plant lines that are otherwise genetically identical], the materials are denied to researchers.”

Huber and Johal recommend using as little glyphosate as possible.

Unfortunately, reducing the dose of glyphosate will be insufficient for killing weeds, particularly as numerous weeds are becoming highly resistant to the herbicide (see [6] GM Crops Facing Meltdown in the USA, SiS 46)

Roundup Ready system alters the whole soil biology

Robert Kremer is a microbiologist with the USDA-ARS (US Department of Agriculture- Agricultural Research Service) and an adjunct professor in the Division of Plant Sciences at the University of Missouri. He started in 1997 to investigate how the new Monsanto Roundup Ready system (Roundup herbicide and GT cropping) would change the level of nematodes in soybean. His research team began looking at the roots and saw microorganisms colonizing the roots, and suspected that glyphosate was having an impact. There was a root fungi problem that seemed to encourage sudden death syndrome.

In fact, the system is “altering the whole soil biology.” Kremer told The Organic & Non-GM Report [7]. “We are seeing differences in bacteria in plant roots and changes in nutrient availability. Many studies show that glyphosate can have toxic effects on [some] microorganisms and can stimulate [others] to germinate spores and colonize roots systems. Other researchers are showing that glyphosate can immobilize manganese, an essential plant micronutrient.”

Glyphosate is toxic to beneficial bacteria like rhiozbia, which fixes nitrogen, but increases the incidence of pathogens like Fusarium. “Some Roundup Ready varieties even without using glyphosate, tend to be more susceptible to Fusarium,” possibly an unintended effect of genetic modification.

If the soil is full of phosphate (as when livestock manure is used as a fertilizer), glyphosate could leach into ground water (and poison other wild-life and human beings).

“We saw the increase of these fungi in the Roundup Ready system, both soybeans and corn.” Kremer said.

The papers describing the work of his research team, published in the European Journal of Agronomy [8] received no publicity in the US.  Kremer said [7]: “I was working with USDA-ARS to publish a news release about these studies. I’ve gone all the way to the administrators, but they are reluctant to put something out. Their thinking is that if farmers are using this (Roundup Ready) technology, USDA doesn’t want negative information being released about it. This is how it is. I think the news release is still sitting on someone’s desk.”

Kremer concluded [7]: “We’re looking at some methods that could be used to overcome negative effects if we continue to use Roundup Ready crops, such as supplementation of nutrients by foliar application,” but added, “I’m more interested in sustainable agriculture. More farmers are interested in using cover cropping to maintain soil quality and other organic amendments. But it’s a steep learning curve for them.”

References

1. Yamada T. Kremer RJ. De Carmargo e Castro and Wood BW. Glyphosate interactions with physiology, nutrition, and diseases of plants: threats to agricultural sustainability? Europ J Agronomy 2009 31, 111-3

2. Ho MW and Cummins J. Roundup Ready sudden death, superweeds, allergens…time to wipe GM crops off the globe. Science in Society 28, 26-27, 2005.

3. Ho MW. Ban glyphosate herbicides now. Science in Society 43, 34-35, 2009.

4. Johal GS and Huber DM. Glyphosate effects on diseases of plants. Eur J Agron 2009, 144-52.

5.  “Scientist warns of dire consequences with widespread use of glyphosate”, The Organic & Non-GMO Report, May 2010, http://www.non-gmoreport.com/articles/may10/consequenceso_widespread_glyphosate_use.php

6. Ho MW. GM crops facing meltdown in the USA. Science in Society 46 (in press).

7. “Scientist finding many negative impacts of Roundup Ready GM crops, USDA doesn’t want to publicize studies showing negative impact2, The Organic & Non-GMO Report, January 2010, http://www.non-gmoreport.com/articles/jan10/scientists_find_negative_impacts_of_GM_crops.php

8. Kremer RJ and Means NE. Glyphosate and glyphosate-resistant crop interactions with rhizosphere microorganisms. European Journal of Agronomy 2009, 31, 153-61.

× 烏有之鄉 WYZXWK.COM

您的打賞將用于網站日常運行與維護。
幫助我們辦好網站，宣傳紅色文化！

歡迎掃描下方二維碼，訂閱烏有之鄉網刊微信公眾號