VOA慢速英语 2007 0605a（在线收听）

This is the VOA Special English Agriculture Report.

Sorghum farmers in eastern Uganda, working with scientists, have tested some lower-cost ways to improve their soil. Little rain and poor soil fertility are problems in that area, as in other parts of southern Africa. Experts from the Kawanda Research Institute in Uganda and the University of Nebraska-Lincoln in the United States did the research.

They say much of the soil lacks enough phosphorus and nitrogen. But for many small farmers, the cost of treating the soil is more than they earn from their crops. 

 
 
So the researchers suggest five methods that could decrease costs and increase production of sorghum. Sorghum is an important food grain in southern Africa.

The methods involve soil fertility management as well as reduced tillage. Tilling is breaking up and turning the soil to prepare the ground for planting.

They say one way to renew the soil is to use a plant called mucuna. Mucuna is a herbaceous vegetable. Its seeds can be planted during the short rainy season. Then the land is free to be planted with sorghum during the best growing season.

Mucuna takes nitrogen from the air and places it in the soil, enriching it. Professor Charles Wortmann, one of the Nebraska researchers, notes that the plants also reseed themselves.

Another method that the scientists suggest is to plant sorghum during one growing season, followed by cowpea the next.

Two other low-input ways to improve the soil involve using manure or nitrogen and phosphorus as fertilizer.

And the fifth way that the study found may improve sorghum production is to reduce crop tillage.

The researchers say the best methods for farmers depend on their individual needs and their resources. For example, using animal waste may be best for farms that have the animals to supply it. But on farms that cannot get fertilizer, the best solution may be the method of rotating sorghum with cowpea.

The researchers tested one hundred forty-two farms across three areas of eastern Uganda. The study took place from two thousand three to two thousand five. The findings have just appeared in Agronomy Journal. Professor Wortmann and other scientists are continuing their research.

And that's the VOA Special English Agriculture Report, written by Jerilyn Watson.