English (en) | Change Language



Just one year ago the Mafie family, Kaneli and Happiness, learned about the value of using Green Manure Cover Crops (GMCCs) to improve the soil on their farm.  Mr. and Mrs. Mafie’s farm consists primarily of coffee and bananas however they also have a corn field intercropped with beans, 60 vanilla vines, beds of spinaches, hot peppers, passion fruits and papaya trees.

The farm is located on an incline at the foothills of Mt. Meru near their home in  Njyeku village of Arumeru, District Tanzania. This area is particularly susceptable to soil erosion due to strong rains, and the Mafies are combating this soil erosion and improving moisture retention by planting Canavalia Ensiformis, known as "Jack Bean." Canavalia, is a cover crop that is highly encouraged to farmers for increasing nitrogen levels in the soil and providing shade for the soil.

Banana planting with Jack Bean as a cover crop

The banana farm using Canavalia Ensiformis (Jack Bean) as a green manure cover crop.

One year on, when entering the coffee and banana farm, it is obvious to see that the soil is well covered by Canavalia, which has helped reduce top soil erosion during strong rains. In addition they tested the impact of Canavalia on the open area of thier maize farm. They found that Canavalia was able to cover the soil, instead of it being open and bare and the canavalia was causing greater moisture retention and therefore healthier maize.

The Mafies’ continue to show neighbors and other farmers their success in using Canavalia. Kanaeli and Happiness hope that within their community the use of Canavalia will expand and a market among smallholder farmers can develop.

Mr. Mafie reports that the one kilo of Canavalia seeds from the ECHO East Africa Seed Bank was divided in half and shared with another farmer; the half kilo of seeds planted has now produced just over ten kilos. From their first harvest of ten kilos, they re-planted seven kilos and successfully sold the other kilos to local farmers. The harvest from the seven kilos planted is pictured below together with individually packaged half kilos to sell to local farmers. The couple says that they are continuously harvesting Canavalia and are expecting to continue using and performing more trials on how Canavalia can further support their farm.

Processing Jack Beans

Drying the Jack Beans

Jack Bean Multiplication

Jack Beans processed and ready for distribution.


ECHOcommunity has many resources available on using green manure cover crops like Canavalia Ensiformis.