The correct answer is: b) Crop rotation and fallow periods.
Shifting cultivation, also known as jhum cultivation, is a traditional agricultural practice found in many parts of the world, including Arunachal Pradesh. It is a form of subsistence agriculture in which farmers clear a small area of forest, cultivate it for a few years, and then abandon it to allow the forest to regenerate. This process is repeated in a different area each year.
Crop rotation and fallow periods are two of the key features of shifting cultivation. Crop rotation helps to prevent soil erosion and nutrient depletion by allowing different crops to be grown in different areas each year. Fallow periods allow the forest to regenerate and replenish the soil with nutrients.
Intensive fertilizer use, large-scale irrigation systems, and monocropping are not characteristic of shifting cultivation. Intensive fertilizer use can lead to soil pollution and nutrient depletion. Large-scale irrigation systems are not typically used in shifting cultivation, as they are expensive and require a lot of energy. Monocropping, the practice of growing a single crop on a large area of land, can also lead to soil erosion and nutrient depletion.
In conclusion, the correct answer is: b) Crop rotation and fallow periods.