Final answer:
Slash-and-burn farming can lead to deforestation, loss of biodiversity, climate impacts, and soil erosion, especially as populations grow and demand for food increases. Shortening fallow periods prevents proper forest regeneration, making the practice unsustainable in the long term. Inga Alley Cropping presents a more sustainable alternative.
Step-by-step explanation:
Slash-and-burn, or shifting cultivation, is a traditional method of agriculture where farmers clear land by cutting down vegetation and burning it to enrich the soil with nutrients from the ash. This practice is often employed in equatorial rainforest climates where the soil is poor in nutrients due to excessive rainfall. While this method requires minimal labor and is calorically efficient, it poses several problems when practiced on a larger scale due to expanding populations.
Deforestation is a major issue with shifting cultivation. It leads to loss of biodiversity, alters rainfall patterns, contributes to greenhouse gas build-up, and results in soil erosion. When populations grow, this practice becomes unsustainable as the demand for food leads to larger areas of forest being cleared and fallow periods being shortened, preventing the forest from properly regenerating.
An alternative to slash-and-burn farming is Inga Alley Cropping, which involves planting crops between rows of nitrogen-fixing Inga trees. This method can preserve forest ecosystems while still providing agricultural yield.