• Sipaseuth, Sipaseuth
• Inthavong, Thavone
• Phengvichith, Vanthong
• Schiller, John
• Vorlasan, Sysavanh
• Thiravong, Khammone
• Souliyavongsa, Xaysathid
• Roth, Christian

Abstract

Mechanised dry direct seeding was tested on farms in Savannakhet Province, Lao PDR as part of activities conducted under the ACIAR-funded ACCA (LWR/2008/019: Developing multi-scale climate change adaptation strategies for farming communities in Cambodia, Lao PDR, Bangladesh and India) and ACCA-SRA (LWR/2012/110: Regional co-learning in simple mechanised tools for rice planting) projects in 2013 and 2014. For most of the households which participated in the testing demonstrations this was the first opportunity to experiment with mechanised dry direct seeding of rice (DSR). In 2013 on-farm trials were conducted to introduce rainfed rice farmers in the districts of Outhoumphone and Champhone to dry direct seeding of wet season rice, provide them with training and support throughout the growing season and learn with them the potential for direct seeding in this region.Sixty six farmers participated in the on-farm testing and over 100ha was sown with the direct seeder.Farmers were most interested in the potential benefits from reduced labour required to establish a rice crop.Through the season we learned that traditional weed control methods (in particular, using standing water to suppress weeds) cannot be relied on in a direct seeded crop and farmers must use other techniques, often at different times of the growing season (e.g. prior to sowing) to control weeds. In 2014 in a smaller trial, on nine farms, a new locally produced seeder which dispersed fertiliser with the seed at sowing was tested.As well, a large emphasis was placed on weed control through land preparation prior to sowing; manual weeding was compared to the application of a post-emergent herbicide.Yield results demonstrated that comparable results could be achieved under both DSR and transplanted rice (PTR), and that similar results can be obtained under manual or chemical weed control. Farmers are reluctant to rely on herbicides for weed control. Gross margins calculated using average 2014 data are higher under DSR+GAP than under PTR+ GAP (and higher again under DSR with chemical weed control).Under a range of labour cost and rice price sensitivities, producing rice under DSR+GAP compared to PTR+GAP, where weeds are well controlled, buffers against an increase in labour cost of up to 50 per cent. These on-farm trials are a proof of concept that DSR is a viable technology to reduce production costs in rainfed lowland Lao PDR; additionally it holds promise to reduce farmers’ exposure to climate risks.A number of key challenges remain outstanding, in particular development of supply chains which will enable all farmers who are interested in mechanised rice to have access to DSR.Many of these issues, in particular sourcing machinery and increasing the capacity and training of key extension partners such as DAEC, PAFO and DAFO will need to be addressed at the policy level. The trials demonstrated many research questions remain to be investigated to better understand DSR in lowland rainfed areas of Lao PDR and to support the households who farm there.These include optimal weed management; timing and placement of fertiliser; time of planting; variety selection; tailoring DSR use to specific soils and/or positions within the toposequence; and practical seeder modifications and improvements.Farmers who participated in this research expressed a keen interest in DSR and, with assistance from local research and extension agencies, are eager to continue to engage in and experiment with dry direct seeded rice to decrease their production costs while maintaining or improving food security and resilience against increasing climate variability and change.

Topics

• impedance spectroscopy
• experiment