Conservation Agriculture is a farming management concept for achieving sustainable and profitable agriculture and subsequent environmental improvements. It is based on enhancing natural biological processes above and below the ground.

Option 1: Avoiding monoculture practices promotes biodiversity, which enhances natural biological processes. This is a component of Conservation Agriculture.

Option 2: Adopting minimum tillage reduces soil disruption and helps maintain natural soil biota and organic matter, which are key principles of Conservation Agriculture.

Option 3: Avoiding the cultivation of plantation crops is not a principle of Conservation Agriculture, rather it depends on the approach used in growing these crops, whether sustainable or not.

Option 4: Using crop residues to cover soil surface prevent soil erosion, retain soil moisture, and can breakdown as organic matter. This practice follows the principle of Conservation Agriculture.

Option 5: Adopting spatial and temporal crop sequencing/crop rotations enhances productivity and favorably affects the environment: a part of Conservation Agriculture.

Hence, options 1, 2, 4, and 5 are principles of Conservation Agriculture; therefore, the correct answer is option 3 (2, 4, and 5).