Field application method most commonly adopted for cereal crops (e.g., wheat, barley) on moderate slopes and typical soils:

Introduction / Context:
Application methods must match crop type, field slope, soil intake rate, and water control objectives. Cereals such as wheat and barley are typically grown in closely spaced stands rather than wide rows, favoring surface methods that uniformly wet large land strips.

Given Data / Assumptions:

• Conventional open-channel irrigation setting.
• Moderate slopes and medium-textured soils common to cereal belts.
• Aim is uniform coverage with manageable labor and cost.

Concept / Approach:

Check methods (check-basin or border-check) divide fields into leveled units bounded by low bunds; water is let in to pond or flow uniformly until the target depth is applied. This suits cereals’ close spacing and provides good distribution with simple control structures.

Step-by-Step Solution:

Verification / Alternative check:

Extension manuals commonly recommend border or check-basin irrigation for wheat and similar cereals in surface irrigation systems.

Why Other Options Are Wrong:

Free flooding causes poor uniformity and high losses; furrow suits row crops; sprinklers/drip are effective but not “most commonly adopted” in traditional cereal areas due to cost and logistics.

Common Pitfalls:

Ignoring field leveling; oversizing checks leading to non-uniform advance; overirrigation near inlets.

Final Answer:

Check (check-basin/border-check) method