首页
登录
职称英语
Fertilizer use has exploded, overloading plants worldwide, likely altering e
Fertilizer use has exploded, overloading plants worldwide, likely altering e
游客
2024-03-13
47
管理
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." [br] It is concluded in the review that______.
选项
A、the use of nitrogen will become sustainable
B、the use of nitrogen will disappear from farms
C、the demand for nitrogen will decrease
D、the demand for nitrogen will increase
答案
C
解析
最后一段第1句中的decrease…substantially和第2句中的increase demand for less use都表明研究人员认为将来对氮的需求将会下降。因此,本题应选C。
转载请注明原文地址:http://tihaiku.com/zcyy/3530546.html
相关试题推荐
[originaltext]Overthepastdecade,theenvironmentalmovementhasexplodedont
[originaltext]Overthepastdecade,theenvironmentalmovementhasexplodedont
Fertilizerusehasexploded,overloadingplantsworldwide,likelyalteringe
Fertilizerusehasexploded,overloadingplantsworldwide,likelyalteringe
Fertilizerusehasexploded,overloadingplantsworldwide,likelyalteringe
Oldstereotypesdiehard.Pictureavideo-gameplayerandyouwilllikelyima
Oldstereotypesdiehard.Pictureavideo-gameplayerandyouwilllikelyima
Oldstereotypesdiehard.Pictureavideo-gameplayerandyouwilllikelyima
Oldstereotypesdiehard.Pictureavideo-gameplayerandyouwilllikelyima
Oldstereotypesdiehard.Pictureavideo-gameplayerandyouwilllikelyim
随机试题
术后呼吸功能不全常见的原因有()A.PaCO2过低 B.体温过低 C.伤
影响车险保费的浮动系数的因素包括()。A.折扣系数 B.耗油量系数 C
根据上图,下列说法正确的是:()A.“十五”时期粮食产量逐年上升 B.
A.阳中之阳 B.阴中之阴 C.阳中之阴 D.阴中之阳 E.阴中之至阴以
基础测绘成果和国家投资完成的其他测绘成果,用于( )的,应当无偿提供。A.进行
细胞色素P450酶(CYP)系中最大的家族是 A.C.YP1 B.C.Y
某城市小区,三面临城市干道,其南侧为支路,总用地为14.5hm2。现状市政管线已
材料1 传统安全威胁犹如挥之不去的梦魇,非传统安全威胁则像“达摩克里斯之剑
线粒体内膜两侧形成质子梯度的能量来源是A.磷酸肌酸水解 B.ATP水解 C.
最新回复
(
0
)