AGRICULTURE REPORT - Study Finds Warmer Nights Mean Less Ric

AGRICULTURE REPORT - Study Finds Warmer Nights Mean Less Rice
By Mario Ritter

Broadcast: Tuesday, July 06, 2004

This is Bob Doughty¹ with the VOA Special English Agriculture Report.

Scientists have had theories that climate change could harm crops. Now, a study offers what it calls direct evidence that rising temperatures at night can shrink harvests of rice.

Scientists from China, the Philippines and the United States did the study for the International Rice Research Institute. The institute is based outside Manila. The report appeared in the United States in the Proceedings² of the National Academy of Sciences.

The researchers used weather information gathered over twenty-five years at the institute's own farm. They also used information on rice harvests at the research farm from nineteen-ninety-two until last year.

The scientists say every increase of one degree Celsius³ in the average daily temperature would decrease rice harvests by fifteen percent. Earlier studies found half that estimate. That was because they did not consider the effects of temperatures at different times of the day.

 
Graphic⁴ Image
The new study found that the average daily temperature in the twenty-five year period increased by seven-tenths of one degree. But nighttime temperatures increased more than a full degree. In fact, the increase was three times greater than the increase in daytimes temperatures. The scientists found that the daytime increase had no clear effect on productivity⁵.

Professor Kenneth Cassman of the University of Nebraska-Lincoln took part in the study. He says the new findings could be explained by the theories of scientists about the effects of global warming.

The scientists say industrial gasses trap heat in the atmosphere, so the ground cannot cool as much at night. Climate studies suggest that average temperatures could increase as much as four-point-five degrees in the next one hundred years.

The researchers in the new study say higher nighttime temperatures may cause the rice plants to spend less energy on growing. Other studies have suggested that grains like wheat and maze⁶ act the same way. But scientists say more work must be done to understand how plants act under conditions of climate change.

Improved crops developed in the nineteen-sixties and seventies mean that rice harvests are now two times greater. Rice production has kept up with population growth so far. But Professor Cassman says the gains needed in the future could be more difficult.

This VOA Special English Agriculture Report was written by Mario Ritter. This is Bob Doughty.

1 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

2 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

3 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

4 graphic   

adj.生动的，形象的，绘画的，文字的，图表的

参考例句：

• The book gave a graphic description of the war.这本书生动地描述了战争的情况。
• Distinguish important text items in lists with graphic icons.用图标来区分重要的文本项。

5 productivity   

n.生产力，生产率，多产

参考例句：

• Farmers are introducing in novations which increase the productivity.农民们正引进提高生产力的新方法。
• The workers try to put up productivity.工人设法提高生产率。

6 maze   

n.迷宫，八阵图，混乱，迷惑

参考例句：

• He found his way through the complex maze of corridors.他穿过了迷宮一样的走廊。
• She was lost in the maze for several hours.一连几小时，她的头脑处于一片糊涂状态。