Jhum cultivation, also known as slash-and-burn agriculture, is a traditional agricultural practice followed by several indigenous communities in the hilly regions of Northeast India, Southeast Asia, and other parts of the world. It involves clearing a patch of land by cutting down and burning the vegetation, cultivating crops for a few years, and then moving on to a new patch of land once the fertility of the soil decreases.

Statement 1: Jhum cultivation was done on large farms.
The first statement is incorrect. Jhum cultivation is typically practiced by small-scale farmers who rely on subsistence farming. They cultivate small plots of land, usually less than a hectare in size, and move on to a new plot after a few years. This rotational system allows the land to regenerate its fertility naturally over time.

Statement 2: Ashes of crops were used as fertilisers.
The second statement is correct. After burning the vegetation, the ashes left behind are used as a source of nutrients for the crops. The ashes, rich in potassium and other minerals, are spread over the cleared land to provide some initial fertility. However, as the cultivation continues and the soil fertility declines, farmers have to move on to a new plot.

In Jhum cultivation, farmers practice shifting cultivation as a way to adapt to the challenging environment of hilly regions. The practice allows for natural regeneration of the forest, as the abandoned plots are left fallow for several years, allowing the forest to grow back. This rotational system also helps in minimizing soil erosion and maintaining the ecological balance.

Jhum cultivation has been a sustainable agricultural practice for centuries, well-suited to the local conditions. However, with increasing population pressure and changes in land-use patterns, the sustainability of Jhum cultivation has come into question. Efforts are being made to provide alternative livelihood options to the communities practicing Jhum cultivation and promote more sustainable practices, such as agroforestry and terrace farming.

In conclusion, the correct answer is option 'B' - Only statement 2 is correct. Jhum cultivation is not done on large farms, but rather on small plots of land, and the ashes of crops are indeed used as fertilizers.

Jhum cultivation also known shifting cultivation was done on small patches of land. They spread the ash from the firing, which contained potash to fertilise the soil.