首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Fertilizer use has exploded, overloading plants worldwide, likely altering ecosystems for decades to centuries, scientists repor
Fertilizer use has exploded, overloading plants worldwide, likely altering ecosystems for decades to centuries, scientists repor
admin
2018-10-16
53
问题
Fertilizer use has exploded, overloading plants worldwide, likely altering ecosystems for decades to centuries, scientists report Thursday. In the journal Science, a review led by Donald Canfield of the University of Southern Denmark found that fertilizer use worldwide increased 800% from 1960 to 2000. "Given the rising costs of synthetic fertilizer production, this overuse is not only economically expensive, but also initiates a series of large-scale environmental impacts," says the review.
Fundamentally, nitrogen from fertilizers has led to an explosion in "dead zones" in seas and oceans, upsetting a cycle of nutrients balanced with growth that has lasted for billions of years, the authors find.
As well, the excess nitrogen is forming large amounts of nitrous oxide(一氧化二氮), a powerful greenhouse gas in wetlands, adding to climate change. Agriculture today produces about a quarter of the nitrous oxide in the atmosphere.
"The effects of humans have been profound. In the last few decades we have doubled the worldwide biological availability of nitrogen, an element that often limits growth of plants and algae," says Thomas Jordan of the Smithsonian Environmental Research Center in Eclgewater, Md., who was not part of the review. The review, "is a very careful analysis of the nitrogen cycle by three of the world authorities in this area," says biochemist Robert Blankenship of Washington University in St. Louis, who also was not part of the review. "The concerns they raise for how the nitrogen cycle is now significantly out of balance are important and need to be addressed by changing agricultural practices. The world’s food supply depends directly on nitrogen application in the form of fertilizer, but current practices are such that much of the applied nitrogen ends up in rivers and eventually in the ocean where it causes serious problems."
"Natural feedbacks driven by microorganisms will likely produce a new steady state over time scales of many decades," say the review authors. "However, because of the projected increase in human population through at least 2050, there will be demand for an increase in fixed nitrogen for crops to feed this population." And that will mean a lot more dead zones, they warn, like the one that blooms yearly, in 2010 about the size of New Jersey, in the Gulf of Mexico.
"Several new approaches and a much wider use of more sustainable time-honored practices, however, can decrease nitrogen use substantially," they conclude. The rising cost and environmental toll of fertilizers will increase demand for less use on farms, they add. "However, even with management, the future cycle will likely be different from the one that preceded the Industrial Revolution."
Thomas Jordan is most likely to believe that______.
选项
A、the review in Science is not convincing enough
B、the findings of the review in Science are justified
C、humans produce worse effects than nitrogen
D、the effects of nitrogen have been neglected
答案
B
解析
从Thomas Jordan所说的话可以知道,他认同氮对生物和环境造成负面的影响,这个观点与the review对化肥和氮的研究结果相同,由此可推断他最可能认为the review的研究结果是合理的。因此,本题应选B。
转载请注明原文地址:https://kaotiyun.com/show/NfH7777K
0
大学英语六级
相关试题推荐
Anybrainexerciseisbetterthanbeingatotalmentalcouchpotato.Buttheactivitieswiththemost【C1】______arethosethatr
TheAmerican【C1】______system,isorganizedaroundabasicallyprivate-enterprise,market-orientedeconomyinwhich【C2】______larg
TheAmerican【C1】______system,isorganizedaroundabasicallyprivate-enterprise,market-orientedeconomyinwhich【C2】______larg
A、St.John’sUniversity.B、MassachusettsInstituteofTechnology.C、UniversityofCalifornia,Berkeley.D、YaleUniversity.A细节题
Educationofexceptionalchildrenmeansprovisionofspecialeducationalservicestothosechildrenwhoareeitherhandicappedo
Nearlytwo-thirdsofbusinessesintheUKwantto【C1】______staffwithforeignlanguageskills.Frenchisstillthemosthighlyp
A、AnOrdinaryperson.B、Adumbperson.C、Adeafandblindperson.D、Arichperson.C选项都与人有关,讲的是什么样的人。题目问的是最有可能买盲文电话的人是谁。文中提到澳大利亚
3D眼镜帮助医生在看不清双手的时候进行外科手术。如今戴着3D眼镜的并非只有电影爱好者,一项新研究表明3D眼镜也能让医生获益。过去,医生对于工作中使用3D技术持怀疑态度,他们更愿意依靠自身经验。但由于3D眼镜或者甚至不需要眼镜的3D技术,这种情况可能要有所改
曲曲折折的荷塘上面,弥望的是田田的叶子。叶子出水很高,像亭亭的舞女的裙。层层的叶子中间,零星地点缀着些白花,有袅娜地开着的,有羞涩地打着朵儿的;正如一粒粒的明珠,又如碧天里的星星,又如刚出浴的美人。微风过处,送来缕缕清香,仿佛远处高楼上渺茫的歌声似的。这时
A、Hefellinatrapmadebyahunter.B、Hehurthisbrainbystayingunderwater.C、Hewasdrownedinanicyriver.D、Hewastrap
随机试题
《企业破产法》第31条规定,法院受理破产申请前一年内,管理人可以请求法院撤销的涉及债务人财产行为的有
常见的与静脉导管相关的感染主要有_______、化脓性血栓性静脉、_______及隐性静脉内感染。
郑某,女,16岁。发作性喉间痰鸣、气促10年,因受寒复发2天。现症见呼吸急促,喉中哮鸣有声,胸膈满闷如塞,咳嗽痰少,咯吐不爽,面色晦滞带青,口不渴,形寒怕冷。舌苔白滑,脉浮紧。查体:双肺满布哮鸣音。宜选用方
呃逆的基本治法是
以下哪种情志异常,可导致心悸、惊恐不安等症状
利益返还请求权的性质是()。
2008年10月,A市B房地产开发公司准备利用A市城市规划区内的C地块,开发建设商品房。通过合法手续,取得了这块土地使用权。另外,该项目建设过程中,经批准,使用临时用地一块。在该项目实施过程中,需要A市人民政府规划行政管理部门审批的证件包括(
对于地表水环境质量标准中氨氮可以采用的测定方法是()。
建设期利息的计算公式为______。
下列各项中,应计入存货实际成本中的有()。
最新回复
(
0
)