Seeing is believing: getting climate-smart in Vietnam
Written by: Bui le Vinh
Edited by: Georgina Smith
“Why does cassava here look so much bigger and better than ours? How have they done it!” Those were the words of one farmer to another in Vietnam’s northern Yen Binh district. The same message echoed down an excited line of farmers. From the Climate-Smart Village (CSV) site of Ma village in the neighboring district of Yen Bai, they had visited the province to observe the series of particularly healthy-looking cassava-forage fields.
Cut and carry for more forages
Leading the visit was Mrs. Nga, village chief and a successful cassava farmer herself, who briefed everyone on the history of the cassava-grass strip model that the farmers had been admiring. The model – high-yielding cassava varieties intercropped with different grasses and tephrosia trees along 5-10m contour lines – was introduced to the village by Vietnam’s Department of Agriculture and Rural Development in 2002. It took a few years for farmers to adopt the new practice – but after 13 years? Remarkable results.
In this village, the farmers plant 75 hectares out of the total 115 hectares to cassava. The other 40ha of land are used to plant cinnamon, styrax, acacia, and small area of tea. There are 80 buffalos and 25 cows for a total of 94 households. Yet there is no land for grazing – all of the cattle are kept in stables and only taken outside to relax at certain times during the day. Cut-and-carry forages, therefore, are very popular here.
Since 2002, agricultural production in the village has changed dramatically. Cassava yields have increased from 12 tons per hectare to an average of 20 tons per hectare. Many farmers can achieve 30 to 40tons per hectare – including Mrs. Nga.
Soil quality has improved remarkably – the result of having accumulated over time behind the lines of grass forage strips. The increase in height of the grass strips (up to 1-1.2m) caused by accumulating soil materials has formed natural terraces. The topsoil at each terrace has become better aerated, and richer in soil carbon content.
The addition of soil carbon stock has come largely from decayed cassava stems and leaves that were left scattered on the surface as mulch, and now forming contour barriers made from cassava stems. After a harvest, cassava stems were piled up along contour lines following the dimensions: 50-60cm (height) – 50-60cm (length) – 30-40cm (width). These cassava barriers helped keep eroded soil materials from being flushed downslope by rain water, and decayed after time, providing good input of organic carbon back to the soil.
Farmers’ livelihoods have increased remarkably thanks to this sustainable farming system. Many have built concrete houses and their children’s education has improved.
Voice from the government of Van Yen
Sharing with the delegation from Yen Binh district, Mrs. Tran Thi Bich Hue – head of Van Yen district’s extension department – stated that having seen unsustainable cassava mono-cropping systems in the past, the government of Van Yen started the initiative of adopting the cassava-grass strips from a finished project in the region. With grass varieties provided by CIAT in 2002, it promoted the cassava-grass campaign in some of the 17 communes of the district. Starting in 2002 with 1000 hectares of cassava-grass strip and 2200 hectares in 2003, there are now 6700 hectares of forages successfully planted in the district of Van Yen.
These sustainable practices were spread mainly through community loud speaker systems and via field demonstrations. Farmers also have played a remarkable role in disseminating the techniques and knowledge to peer farmers to follow.
Lessons learned: Besides farmers’ great participation in the project, the role of the local government is very important in achieving the project’s goals and in scaling out the practice of growing grass strips along contour lines to protect the soil. The involvement of organizations like CIAT was also very important in providing technical support and establishing the practice.
Way forward: Since cassava intercropping with grass strips is one of preferred interventions by farmers in the CSV of Ma village, successful farmers Mrs. Nga and Mrs. Hue were invited as technical experts to educate farmers.
This initiative is part of the wider CCAFS Flagship “Community Learning” project, to spread information between communities in Climate-Smart Villages.
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