By VOA
24 September, 2012
This is the VOA Special English Agriculture Report.
Studies show farmland in Africa is often lacking in important nutrients. But researchers say a combination of farming methods may help.
Since the world food crisis several years ago, researchers have directed more of their attention to small farms. Most farms in areas south of the Sahara Desert are only about one or two hectares. One of the goals is to increase production without necessarily clearing more land to grow additional crops.
Using Evergreen Agriculture, Rhoda Mang'yana grows maize near Faidherbia trees to improve crop yields and soil fertility on her farm. (Credit: Jim Richardson) |
American researchers say that can happen with greater use of an agricultural system called perenniation. It mixes food crops with trees and perennial plants – those that return year after year.
Soil scientist John Reganold is with Washington State University.
JOHN REGANOLD: "One of the major problems (is that the) soils are fairly poor in most of the regions. So how do you grow food on poor soils? There have to be food production systems that can build the soil and improve the yield."
Mr. Reganold says poor soil may have resulted from years of weathering that washed away many nutrients. He says some farmers may have done more harm than good.
JOHN REGANOLD: "They have been actually using farming practices where they're not putting in organic matter. They're not putting in fertilizers. They can't afford those things. And it just runs the soil down. So they're worsening the situation."
He estimates that up to two billion dollars worth of nitrogen, phosphorous and potassium is lost from African soil each year.
The scientist says the word perenniation defines three systems that are already used in Africa. The oldest of the three is called evergreen agriculture. This is where farmers plant trees with their crops. John Reganold says farmers in Africa have been doing this for sixty years, but it seems to be growing in popularity.
The method is gaining widespread use in countries such as Niger, Burkina Faso, Malawi and Zambia. The trees are planted among maize, millet or sorghum crops. They not only add nitrogen to the soil through their roots, but also through their leaves when they fall off and break down. At other times of the year, the trees can protect plants from strong sunlight.
John Reganold says he knows of one woman who has had great success with perenniation.
JOHN REGANOLD: "She's a grandmother in her fifties. Her name is Rhoda Mang'yana and she started using this system about twenty years ago. And her yields initially were about a ton of maize. Now with a good year she gets four tons per hectare. Four times what she was getting."
Mr. Reganold was one of three researchers who wrote a report about perenniation. It was published in the journal Nature.
And that's the VOA Special English Agriculture Report. I'm Steve Ember.
This is the VOA Special English Agriculture Report.
這里是美國之音慢速英語農(nóng)業(yè)報道。
Studies show farmland in Africa is often lacking in important nutrients. But researchers say a combination of farming methods may help.
研究顯示非洲農(nóng)田通常缺乏重要養(yǎng)分。但研究人員表示,結(jié)合多種耕種方法會有所幫助。
Since the world food crisis several years ago, researchers have directed more of their attention to small farms. Most farms in areas south of the Sahara Desert are only about one or two hectares. One of the goals is to increase production without necessarily clearing more land to grow additional crops.
由于幾年前的世界糧食危機,研究人員將更多注意力投向了小農(nóng)場。在撒哈拉沙漠以南地區(qū)的大多數(shù)農(nóng)場的規(guī)模只有大約一兩公頃。研究人員的目標之一就是在無需清理出更多土地種植其它作物的前提下提高產(chǎn)量。
American researchers say that can happen with greater use of an agricultural system called perenniation. It mixes food crops with trees and perennial plants – those that return year after year.
美國研究人員表示充分利用多年生農(nóng)業(yè)體系可以實現(xiàn)這個目標。該體系是將糧食作物和樹木以及多年生植物混種。
Soil scientist John Reganold is with Washington State University.
土壤科學家約翰·雷甘納德(John Reganold)就職于華盛頓州立大學。
JOHN REGANOLD: "One of the major problems (is that the) soils are fairly poor in most of the regions. So how do you grow food on poor soils? There have to be food production systems that can build the soil and improve the yield."
雷甘納德:“其中一個重要問題就是,很多地區(qū)的土壤都比較貧瘠。如果在貧瘠的土地上種植糧食呢?必須具備可以培育土壤并提高產(chǎn)量的糧食生產(chǎn)體系。”
Mr. Reganold says poor soil may have resulted from years of weathering that washed away many nutrients. He says some farmers may have done more harm than good.
雷甘納德表示,土壤貧瘠可能是因為多年的水土流失造成的。他說,一些農(nóng)民的做法對土地弊大于利。
JOHN REGANOLD: "They have been actually using farming practices where they're not putting in organic matter. They're not putting in fertilizers. They can't afford those things. And it just runs the soil down. So they're worsening the situation."
雷甘納德:“他們實際使用的耕作方式不是投入有機物質(zhì)和肥料,他們買不起這些。這樣一來土壤養(yǎng)分下降,情況持續(xù)惡化。”
He estimates that up to two billion dollars worth of nitrogen, phosphorous and potassium is lost from African soil each year.
他估計每年非洲土壤流失的氮、磷、鉀的價值超過20億美元。
The scientist says the word perenniation defines three systems that are already used in Africa. The oldest of the three is called evergreen agriculture. This is where farmers plant trees with their crops. John Reganold says farmers in Africa have been doing this for sixty years, but it seems to be growing in popularity.
科學家表示,多年生農(nóng)業(yè)體系定義的三大體系已經(jīng)在非洲被運用。三大體系中最早被運用的是常綠農(nóng)業(yè)體系,即農(nóng)民們種植莊稼的同時種樹。雷甘納德表示,非洲農(nóng)民已經(jīng)這樣干了60年,但這種體系似乎越來越普遍。
The method is gaining widespread use in countries such as Niger, Burkina Faso, Malawi and Zambia. The trees are planted among maize, millet or sorghum crops. They not only add nitrogen to the soil through their roots, but also through their leaves when they fall off and break down. At other times of the year, the trees can protect plants from strong sunlight.
這種做法在尼日爾、布基納法索、馬拉維和贊比亞等國家得到了廣泛運用。樹木種植在玉米、小米和高粱作物之間。它們不僅可以通過根部增加土壤中的氮,樹葉掉落并分解后也能提供氮。而在一年中的其它時間,樹木可以防止作物受到強烈日曬。
John Reganold says he knows of one woman who has had great success with perenniation.
雷甘納德表示他認識一位通過多年生農(nóng)業(yè)體系取得巨大成功的女性。
JOHN REGANOLD: "She's a grandmother in her fifties. Her name is Rhoda Mang'yana and she started using this system about twenty years ago. And her yields initially were about a ton of maize. Now with a good year she gets four tons per hectare. Four times what she was getting."
雷甘納德:“她是一位50多歲祖母,她的名字是 Rhoda Mang'yana。大約20年前她開始采用這一體系。起初她的玉米產(chǎn)量只有一噸左右?,F(xiàn)在如果年頭好,每畝她能收獲4噸。產(chǎn)量翻了4倍。”
Mr. Reganold was one of three researchers who wrote a report about perenniation. It was published in the journal Nature.
雷甘納德是撰寫有關(guān)多年生農(nóng)業(yè)體系報告的三位研究人員之一。該報告發(fā)表在《自然》雜志上。