Capacity development and innovative communication

G. Smith (CIAT)

Cassava farmers learn intercropping lessons from their peers

Southeast Asia

When it comes to learning a new approach in farming, nothing beats first-hand experience. That’s why, in 2015, a group of farmers in northeast Vietnam visited high-yielding cassava fields in a nearby district. The delegation, from Ma Village in Yen Binh District, travelled to Van Yen District where farmers practise a new way of growing cassava – one that produces good results despite climate change impacts, such as increased flash flooding.

Ma Village is one of several Climate-Smart Villages, designated by a partnership between CCAFS, the International Center for Tropical Agriculture (CIAT) and community members as test beds for climate-smart agriculture. So, it made sense for farmers from the village to see for themselves farming adaptations that cope with the effects of climate change.

“Why does cassava here look so much bigger and better than ours? How have they done it?!” Farmer from Ma Village, Vietnam

What the farmers found when they visited Van Yen was a system of intercropping where cassava is grown between grasses and tephrosia trees along 5–10 m contour lines. Van Yen farmers initiated this system in 2002 using grass varieties provided by CIAT. The idea behind the system was that it would improve soil quality and reduce the amount of erosion caused by intense periods of rainfall.

It seems that the system has done just that. Soil quality has improved remarkably – as cassava stems and leaves have been left to accumulate over time behind grass strips. The resulting increase in height of these grass strips (up to 1.0-1.2 m) has formed natural terraces where the soil is well aerated and rich in carbon content.

The farmers from Ma Village learned that the increase in soil quality in Van Yen has enabled cassava production to rise dramatically. Over 13 years, cassava yields have risen from 12 to 20 tonnes per hectare, with some farmers achieving 30 to 40 tonnes per hectare. On top of this, farmers can ‘cut and carry’ grass as forage to feed their cattle, for which there is insufficient grazing land in the district. Once cassava roots are harvested, the stems and leaves are left on the land surface as nourishing mulch during the off-season.

Nguyen Duy Nhiem (CIAT-Vietnam)

Motivated by the success they witnessed in Van Yen, the visiting delegation is keen to replicate cassava intercropping back in Ma Village. The visit, therefore, demonstrates how peer-to-peer learning is a vital contributor to the out-scaling of climate-smart farming systems.

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