Jhumming, also known as shifting cultivation or slash-and-burn agriculture, refers to a traditional farming practice that involves clearing a patch of land by cutting down and burning vegetation, cultivating crops for a few years, and then abandoning the plot to allow the land to regenerate. It is primarily practiced by indigenous communities in hilly and forested regions around the world.

In the context of the given options, jhumming is associated with option 2, which is 'slash and burn' agriculture in the northeastern states of India. This agricultural practice is prevalent in states such as Meghalaya, Nagaland, Manipur, and Mizoram, where the terrain is hilly and forest cover is abundant.

Key points to consider:

1. Primitive farming technique: Jhumming is considered a primitive farming technique as it has been practiced for centuries by indigenous communities. It involves minimal use of modern machinery and relies on traditional knowledge and practices.

2. Slash and burn process: Jhumming involves clearing a patch of land by slashing and burning the existing vegetation. This process helps in releasing nutrients into the soil and preparing it for cultivation.

3. Rotational cultivation: After the land is cleared, crops such as rice, millet, maize, and vegetables are cultivated for a few years. However, due to the depletion of nutrients in the soil and the growth of invasive weeds, the productivity of the land decreases over time.

4. Regeneration period: Once the fertility of the land declines, the plot is abandoned, and the farmers move on to clear a new patch of land for cultivation. The abandoned plot is left fallow for several years to allow the natural regeneration of vegetation and the restoration of soil fertility.

5. Environmental impact: While jhumming has been a sustainable practice for indigenous communities in the past, population growth, increased agricultural pressures, and changes in land use patterns have led to its negative environmental consequences. Deforestation, soil erosion, loss of biodiversity, and greenhouse gas emissions are some of the issues associated with jhumming.

In conclusion, jhumming or shifting cultivation is primarily associated with 'slash and burn' agriculture in the northeastern states of India. It is a traditional farming practice that involves clearing land, cultivating crops for a few years, and then allowing the land to regenerate naturally. However, due to its negative environmental impacts, efforts are being made to promote sustainable alternatives and provide support to indigenous communities practicing jhumming.