Slash and burn agriculture is a farming technique used by hundreds of mThe illions of farmers. It involves "slashing" down vegetation in a specific plot of land, burning the rest, and utilizing the ashes as nutrients for the incoming crops. The technique is used all over the world, from Africa to Central America to Asia. Some of the benefits of slash and burn agriculture are the plot is almost completely free of weeds, and the ashes provide some nutrients. However, there are many negatives, one of the biggest ones being that this time of farming causes the soil's fertility to eventually decrease, and for it to increase at any point the farmer would have to destroy more land to grow his crops while another plot is recovering.
Some other negatives are biodiversity loss, nutrient loss, erosion, and deforestation. Because of how much land is being cut down and burned, many species of plants and animals are losing habitat that was already scarce to begin with. Also, eventually, the field will lose all of it's nutrients, become useless to the farmer, and then the farmer has to slash and burn another plot of land. When fields are slashed and burned next to each other, many nutrients and lots of water escapes, and the roots are unable to prevent this. Finally, with millions of farmers slashing and burning millions of acres of land per year, there is a huge deforestation problem.
Some other negatives are biodiversity loss, nutrient loss, erosion, and deforestation. Because of how much land is being cut down and burned, many species of plants and animals are losing habitat that was already scarce to begin with. Also, eventually, the field will lose all of it's nutrients, become useless to the farmer, and then the farmer has to slash and burn another plot of land. When fields are slashed and burned next to each other, many nutrients and lots of water escapes, and the roots are unable to prevent this. Finally, with millions of farmers slashing and burning millions of acres of land per year, there is a huge deforestation problem.
http://upload.wikimedia.org/wikipedia/commons/b/bf/Slash_and_Burn_Agriculture,_Morondava,_Madagascar.jpg