The Slash and Burn Agriculture
WHAT IS SLASH AND BURN AGRICULTURE?
Slash and burn agriculture, is a farming method that involves the cutting and burning of trees or crops in a large area.
The method begins by cutting down the crops in an area. The cut-down vegetation, or slash, is then left to dry. Then, the biomass is burnt which forms a nutrient-rich layer of ash that makes the soil fertile. After about 3-5 years, the plot’s productivity decreases, causing the farmers to abandon the field and move over to a new area where the entire process is repeated.
Slash-and-burn agriculture has been used for thousands of years. But today, with more people than ever trying to survive with the limited natural resources, it’s impact is especially devastating and unsustainable.
HOW DOES IT AFFECT THE CLIMATE?
There are several issues that result from this method of growing crops. One of the major issues is deforestation. A direct consequence of it is an increase in air pollution and the release of carbon into the atmosphere which contributes to global climate change and an increase in accidental fires.
Deforestation due to slash-and-burn in the tropical regions disrupts the rainfall pattern. Moreover, replacing tropical forests with crops and pastures leads to a drier and hotter climate in the tropics. Deforestation increases the rainfall by creating “hot islands” that add to the rising and overturning of air (convection) which further gives rise to clouds and rain. Clouds and rainfall become concentrated over clearings.
HOW DOES IT LEAD TO GLOBAL WARMING?
The trees contain more carbon than what humans may produce in 10 years. When people clear forests with fire, the carbon in the wood returns to the atmosphere, increasing global warming. The soil becomes a huge source of carbon emissions once it is cleared for crop land, depending on how the farmers use the land. The soils of swampy lowland forests are rich in peat (partially decayed organic matter). During droughts, the peat as well as the forests become flammable, particularly when they are degraded. When burnt, they release huge volumes of carbon dioxide and other greenhouse gases which not only make the air toxic but also leads to global climate change.
WHAT CAN BE DONE?
Burning the trees is an unfit way of fertilizing the soil. Many of the important nutrients are ruined due to the heat of the fire. The fields that are produced by the technique of slash-and-burn are not able to support agriculture for more than 3-5 years. As a result of which another field must be produced by burning more land. When trees are cut down, no nutrients are returned to the soil.
However, if the wealth acquired from the sale of lumber was invested in fertilizers the land would sustain for a longer period of time. Another alternative is to merge agriculture with animal husbandry, the waste from the animals can be used as a natural fertilizer. The use of fertilizer can replace the burning of trees to produce fertile land in the forest for agriculture.
These are a few links wherein you can donate to help stop slash and burn farming for clean air and a healthy planet!