Every year in Southeast Asia (March-May), we have what we call ‘the burning season’, a period of severe air pollution stemming from the burning of forests and croplands. Here in Thailand, in the northern city of Chiang Mai, it gets especially bad, sustaining AQI (Air Quality Index) numbers of over 200 and at times exceeding 400. For reference, any AQI rating over 150 is considered unhealthy; anything over 300 is considered hazardous! These levels of air pollution lead to chronic health issues, respiratory and otherwise, and are largely unavoidable by residents.
Our approach is to provide local smallholder farmers with an alternative to burning. Using a simple mechanical implement called a ‘Roller-Crimper’, we can keep all of that beneficial organic matter on the ground (in the soil where it belongs) and prevent it from going up in smoke.
The approach is quite simple. At the end of the growing season, we recommend planting a cover crop instead of the traditional fallow period that would follow the harvest. In this way, the soil stays covered, protected from wind and rain erosion, weeds are suppressed, and large amounts of carbon can be sequestered through photosynthesis. When the farmer is ready to plant a crop again, it can be rolled using a simple mechanical device instead of burning it, turning it into a nice thick mat of mulch. This technique also prevents the turning of soil and loss of carbon to the atmosphere, and actually ‘pulls’ carbon out of the atmosphere, where it is detrimental, bringing it back to the soil in the form of organic plant matter.
While cover crops can be hugely beneficial, their management typically requires the use of synthetic herbicides, trading one environmental hazard for another. With the roller-crimper, it is possible to manage cover crops, without the need for herbicides. The farmer rolls over the cover crop, the ‘crimper’ breaks the stems, and the cover crop stays down. No need to burn, no need to turn [the soil].
Financiado pelo capítulo STEAM (August 2021)