What is Slash-and-burn?
'''Slash-and-burn''' is a [[farming]] technique that has been used for thousands of years. Usually at the start of the [[dry season]], a plot of land is cleared of its [[vegetation]]. Very often, this is done manually, for example using [[Machete|machetes]]. This can take a long time, clearing a [[hectare]] can take up to 120 hours of work. If the land is to be used for [[Crop|crops]] that last [[Perennial|more than two years]], the [[Root|roots]] need to be cleared as well. Usually this is not done for [[Annual plant|annual plants]]. The plants cleared are left to dry, often for weeks. When they are dry enough, they are burnt. The [[ash]] that is created makes the [[soil]] [[fertile]]. [[Weed|Weeds]], and other [[Pest (biology)|pests]] have also been eliminated, so the field can be used for [[agriculture]]. After three to five years, the extra fertility is gone, and the [[farmer]] usually moves to another field (or again uses slash-and-burn). == Problems == While the technique is very simple, it also has problems: Often, fires created get out of control, and more land is burned than necessary. That way, a territory the size of [[Belgium]] burned down in a fire, created in 1989, in the state of [[Roraima]] in [[Brazil]]. In general, there are few large fires in the [[rainforest]]. the [[climate]] is very wet, and [[River|rivers]] block the fires. In [[southeast Asia]], between May and October, many people have health problems because of the clouds of smoke. During that time, slash-and-burn operations happen in [[Indonesia]]. These fires are responsible for the clouds. Millions of people use slash-and-burn agriculture, often as a way of [[subsistence farming]]. For this reason, the practice cannot be outlawed. Some steps can be taken ot lessen the impact on the ecosystem: * Improving soils, for example with [[charcoal]]. see also [[terra preta]]. * Adding fast-growing tree species to the primary forest. These trees grow faster than the primary forest. * Instead of burning it, the biomass can be cut into s