AGRICULTURE REPORT - Irrigation and Salt

AGRICULTURE REPORT -May 21, 2002: Irrigation and Salt

By George Grow
This is the VOA Special English AGRICULTURE REPORT.

Irrigation is the watering of land by other than natural methods. Irrigation projects provide water for crops in
areas that have long periods of little or no rainfall.

The United Nations Food and Agriculture Organization reports that only seventeen
percent of all cropland is irrigated¹. However, irrigated land provides forty percent of
the world’s food. Irrigation is said to increase production of most crops by one-
hundred to four-hundred percent.

However, F-A-O officials say about ten percent of all irrigated land has been
damaged by salt. This is most severe in extremely dry areas. As much as twenty-five
percent of the land is affected² in these areas.

F-A-O officials say this has become a threat to food security³. In the past, the U-N agency⁴ said that increasing the
use of irrigation could be the answer to feeding the world’s people. Now, it warns that rising salt levels in the
soil threaten much existing irrigated land.

Salinization is the build-up of salt in the soil. F-A-O officials say salinization reduces productivity⁵ and can
seriously damage the soil. It warns that salinization is reducing the world ’s irrigated land by one to two percent
each year.

All soil contains some salt. As water wears away rocks and soil, small amounts of mineral salts are carried into
rivers and other waterways. If a field has too little water, the mineral salts are not washed away. They remain in
the soil.

However, the worst danger to the soil is from too much water. When the ground is too wet, water levels rise. The
water evaporates⁶. However, salt remains⁷ underground, around plant roots. This interferes⁸ with the ability of the
roots to take in needed water.

The F-A-O says there are several ways to prevent or reduce salinization. One is for farmers to use just a little
more water than the crops need. The extra water can carry salt away from the roots of the plants. Farmers can
also build underground pipes or dig deep holes near crops. This can help remove extra water.

Finally, farmers can flood their fields. This can sometimes treat badly salinized land that can on longer be used
for agriculture. Adding a lot of water can be costly⁹. But F-A-O officials say it may be a wise economic decision,
depending on the value of the land and crops.

This VOA Special English AGRICULTURE REPORT was written by George Grow.

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1 irrigated   

[医]冲洗的

参考例句：

• They irrigated their crops with water from this river. 他们用这条小河里的水浇庄稼。
• A crop can be sown, weeded, irrigated, and fertilized uniformly. 一种作物可以均匀一致地进行播种，除草，灌溉和施肥。

2 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

3 security   

n.安全，安全感；防护措施；保证(金)，抵押(品)；债券，证券

参考例句：

• A security guard brought him down with a flying tackle.一名保安人员飞身把他抱倒。
• There was tight security at the airport when the President's plane landed.总统的专机降落时，机场的保安措施很严密。

4 agency   

n.经办；代理；代理处

参考例句：

• This disease is spread through the agency of insects.这种疾病是通过昆虫媒介传播的。
• He spoke in the person of Xinhua News Agency.他代表新华社讲话。

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 evaporates   

v.（使某物）蒸发掉( evaporate的第三人称单数 )；消失，不复存在；使脱水

参考例句：

• Heat evaporates water into steam. 水受热变成水蒸气。 来自《简明英汉词典》
• As the water evaporates, a crust of salt is left on the surface of the soil. 随着水分的蒸发，地面上留下了一层结晶盐。 来自辞典例句

7 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

8 interferes   

vi. 妨碍，冲突，干涉

参考例句：

• The noise interferes with my work. 这噪音妨碍我的工作。
• That interferes with my plan. 那干扰了我的计划。

9 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。