A new study in West Africa shows how farm irrigation systems powered by the sun can produce more food and money for villagers. The study in Benin found that solar-powered pumps are effective in supplying water, especially during the long dry season.

Sub-Saharan Africa is the part of the world with the least food security. The United Nations Food and Agriculture Organization estimates that more than one billion of the world's people faced hunger last year. Around two hundred sixty-five million of them live south of the Sahara Desert. Lack of rainfall is one of their main causes of food shortages.

Jennifer Burney from Stanford University in California led the study. The research team helped build three solar-powered drip irrigation systems in northern Benin.

Between thirty and thirty-five women used each system to pump water from the ground or a stream. Each woman was responsible for farming her own one hundred twenty square meters of land. They also farmed other land collectively.

The solar-powered irrigation systems produced an average of nearly two metric tons of vegetables per month. During the first year, the women kept a monthly average of almost nine kilograms of vegetables for home use.

They sold the surplus produce at local markets. The earnings greatly increased their ability to buy food during the dry season which can last six to nine months.

People in the two villages with the systems were able to eat three to five more servings of vegetables per day. But making the surplus available at markets also had a wider effect.

The study compared the villages with two others where women farmed with traditional methods like carrying water in buckets. The amount of vegetables eaten in those villages also increased, though not as much.

The researchers note that only four percent of the cropland in sub-Saharan Africa is irrigated. Using solar power to pump water has higher costs at first. But the study says it can be more economical in the long term than using fuels like gasoline, diesel or kerosene. And solar power isenvironmentally friendly.

The study appears this month in the Proceedings of the National Academy of Sciences.

用太阳能泵帮助非洲农民

一项新的研究向人们展示了太阳能农业灌溉系统是如何提高村民的农作物收成和收入的。在非洲贝宁进行的该项研究发现，太阳能 泵的泵水能力非常强，尤其是在漫长的干旱季节里。

撒哈拉以南非洲是世界上最缺乏粮食安全保障的地区。联合国粮农组织估计，去年全球有超过一亿的人面临饥饿威胁，其中约2650万人生活在撒哈拉以南非洲。少雨是造成该地区人民食物短缺的主要原因之一。

来自斯坦福大学的Jennifer Burney是该项研究的负责人，在研究组的帮助下，贝宁北部建起了三座太阳能滴灌系统。

每30-35名妇女共用一座太阳能滴灌系统来泵取地下水或溪水。每名妇女除了负责耕作她自己的220平方米的农地以外，还与其他妇女们共同耕作其它的农地。

太阳能滴灌系统平均每月为村民们生产将近2公吨的蔬菜。在太阳能滴灌系统投入使用后的第一年里，每名妇女的家庭每月平均有将近9公斤的自用蔬菜。

妇女们将吃不完的蔬菜拿到当地市场上出售。卖菜赚得的钱大大提高了她们在旱季里购买食物的能力。而旱季有可能持续半年到9个月。

在其中2条有太阳能滴灌系统的村里，村民们每天能够食用多五份的蔬菜。但将多出来的蔬菜拿到市场上去卖的话，村民们得到的实惠更多。

研究组将参加研究的村落与其它2条村落进行对比。在那2条村落里，妇女们用传统的方式进行农地灌溉，如用桶运水。2条村里食用的蔬菜量也有所增加，虽然增加的量并不多。

研究人员注意到，只有4%的撒哈拉以南非洲的农地得到灌溉。用太阳能泵水的初期费用较高，但研究组说，长期来看，使用太阳能灌溉系统比使用汽油、柴油或煤油划算。而且太阳能是清洁能源。