Swapping slash-and-burn for conservation agriculture
Slash-and-burn is a traditional farming method used by many subsistence farmers. But the practice both harms the soil and accelerates global warming. A project in Ghana promotes conservation agriculture instead.
Transcript
00:00 Africa is burning. A thick cloud of smoke hangs over a large part of the continent
00:07 several times each year. Satellite images from NASA show how fires stretch like a red
00:13 carpet from Central Africa across the South East all the way to Madagascar.
00:19 Small scale farmers like Fusuyeni Isufu regularly burn their fields. It is a widely practiced
00:25 technique.
00:30 The fields are exhausted and produce no yield. So I'm preparing this land for plowing. If
00:35 you don't cut and burn the vegetation that's here, you can't plow it.
00:40 Though this may seem relatively harmless in rural northern Ghana, the practice exacerbates
00:46 climate change. Slash and burn agriculture is a quick and low cost way of prepping land
00:52 for planting. The fire releases nutrients sequestered in grasses and bushes such as
00:57 nitrate, sulfur and potassium. That's free fertilizer for farmers. Unfortunately, the
01:03 technique is not very effective. For instance, 90 percent of nitrate disappears when burned.
01:10 So the soil is soon depleted again, says Tiffin Yeboah, an agronomist in Accra.
01:15 Slash and burn farming practices have significant impact on food production because one, it
01:21 leads to soil degradation and soil is the basic resource for food crop production. And
01:26 for that matter, you have high levels of erosion all over. And then it is estimated that about
01:32 20,000 tons of nutrients are mined through soil irrigation every year. And that is very,
01:38 very significant when it comes to food production. So you have all these nutrients that is required
01:43 for food production being mined through soil erosion.
01:47 Another issue is the use of heavy machinery. Tractor tires compact the soil, while earth
01:52 churned up by plows dries out quickly. The result, erosion and desertification.
01:59 Many in northern Ghana depend on farming for a living. Now, an EU-funded project wants
02:04 to convince farmers here to simply do nothing, that is, to let their fields live fallow for
02:10 a while.
02:11 In fact, there are people who even think that if you don't burn your land, you can't
02:18 farm. So that is quite a challenge, that the knowledge and awareness of CA is not out there.
02:25 Also, the period of transitioning from conservation, from conventional agriculture to conservation
02:36 agriculture, there is a time gap where you will not fully get the benefit of CA. And
02:43 that also is sometimes a discourage for some people to do that transition.
02:51 CA, or conservation agriculture, means no slashing, burn and no plowing. Practicing
03:03 succession planting keeps the earth moist. The plant roots loosen the soil, enabling
03:08 it to recover and increasing biodiversity.
03:15 The project taught us methods which we didn't know before.
03:26 We used to plow the field with tractors.
03:33 They taught us not to slash and burn the field, along with other methods, like planting different
03:40 crops every year on the same land, or to do mixed cropping on the land. And it's working
03:55 out quite well.
04:02 Saiba Selima signed up for the workshop because she often couldn't afford to rent a tractor.
04:07 Now her family has enough to eat. The mother of three regularly struggled to feed her family
04:12 with what her land could provide. Thanks to the succession planting, there is now a variety
04:17 of vegetables and grains throughout the year. Switching to the new farming methods has been
04:23 worth it. And Sabina Selima even has enough corn left over for her current harvest to
04:30 sell at the market.
04:31 (splashing)