Which agricultural technique allows soil to regain nutrients after crop use?

The correct choice is crop rotation because it is an agricultural technique that involves growing different types of crops in the same area across seasons. This practice improves soil health by allowing different plants to utilize varying nutrients from the soil. Some crops, such as legumes, can even fix nitrogen in the soil, which replenishes this essential nutrient that is often depleted by constant cropping.

In contrast, cropping intensification focuses on increasing yield from the same land area, which can lead to nutrient depletion over time if the soil is not managed carefully. Monoculture, or the cultivation of a single crop over an extensive area, can result in soil nutrient depletion and increased vulnerability to pests and diseases due to reduced biodiversity. Permanent pastures may provide stability and reduce soil erosion, but they do not actively restore nutrients in the way that crop rotation does. Therefore, crop rotation is the most effective technique among the options to restore and maintain soil nutrients after crop use.