Shifting cultivation is an agricultural system in which plots of land are cultivated temporarily, then abandoned while post-disturbance fallow vegetation is allowed to freely grow while the cultivator moves on to another plot. It is also called JHUM CULTIVATION.

Explanation:

Jhum cultivation is the process in which farmers cut down the trees of a forest and burn the plant remains. This practice is commonly followed by indigenous communities in many parts of the world, especially in Northeast India, Southeast Asia, and parts of Africa and South America.

Process of Jhum cultivation:
1. Selection of land: The farmers select a suitable piece of land in the forest where they want to carry out jhum cultivation.
2. Clearing the land: The farmers cut down the trees and vegetation in the selected area. This is usually done by slash-and-burn method, where the trees and plants are first cut and left to dry, and then burned to clear the land.
3. Burning the plant remains: After clearing the land, the farmers set fire to the dried plant remains. This is done to remove the remaining vegetation and to provide nutrients to the soil through ash deposition.
4. Sowing the crops: Once the land has been cleared and burned, the farmers sow their crops. They usually grow crops like maize, millet, rice, and vegetables.
5. Cultivation and harvesting: The crops are cultivated and harvested in due course. The farmers rely on the natural fertility of the soil for their crop production.
6. Shifting to a new plot: After a few years, when the soil fertility decreases, the farmers abandon the plot and move on to a new area of the forest for cultivation. The abandoned land is left fallow for several years, allowing it to regenerate and regain its fertility.

Reasons for jhum cultivation:
- Jhum cultivation is a traditional practice that has been followed by indigenous communities for centuries. It is a way for them to sustain their livelihoods and meet their subsistence needs.
- It allows farmers to grow a variety of crops in a diverse ecosystem, ensuring food security and reducing the risk of crop failure.
- The burning of plant remains helps in nutrient recycling and soil rejuvenation. The ash acts as a natural fertilizer, enriching the soil with essential minerals.
- Shifting cultivation also allows the forest to regenerate and maintain its biodiversity. The fallow period allows for the regrowth of trees and vegetation, restoring the ecological balance.

Impact of jhum cultivation:
- Jhum cultivation has been criticized for its negative impact on the environment. The practice of clearing land and burning plant remains contributes to deforestation, loss of biodiversity, and soil erosion.
- It can lead to soil degradation and nutrient depletion, making the land less productive over time.
- The practice is also seen as unsustainable in the long run, as population growth and increased demand for agricultural land have led to shorter fallow periods and increased pressure on the forest.

Conclusion:
Jhum cultivation is a traditional agricultural practice followed by indigenous communities. While it has its advantages in terms of food security and livelihoods, it also has negative impacts on the environment. Efforts are being made to promote sustainable alternatives to jhum cultivation and to support indigenous communities in transitioning to more sustainable farming practices.