Assertion: One of the major problems of shifting cultivation is that the cycle of jhum becomes less and less due to loss of fertility in different parcels.

Reasoning: In Jhum cultivation, the vegetation is usually cleared by fire, and the ashes add to the fertility of the soil.

Both (A) and (R) are true but (R) is not the correct explanation of (A)

In jhum cultivation, the vegetation is usually cleared by fire, and the ashes add to the fertility of the soil. The major problem of shifting cultivation is that the cycle of jhum becomes less and less due to loss of fertility in different parcels.