Kor watering for wheat in North Indian plains: What is the optimum depth of the first (kor) irrigation for a wheat crop under typical North Indian field conditions?

Introduction / Context:
Kor watering is the initial irrigation essential for crop establishment. For wheat in North Indian plains, a standard kor depth is used in design and exam problems to guide water allocation during the critical early stage of growth.

Given Data / Assumptions:

• Crop: Wheat.
• Region: North Indian plains.
• We require a commonly used benchmark depth for objective questions.

Concept / Approach:
Wheat needs sufficient moisture to ensure germination and early root development, but it is not as water-intensive as rice at establishment. A kor depth around 13.5 cm is widely cited in standard irrigation scheduling problems for the region.

Step-by-Step Solution:
Recognize wheat’s moderate initial water need.Adopt standard tabulated kor depth for the region’s exam practice.Select 13.5 cm.

Verification / Alternative check:
While on-farm adjustments may occur due to soil texture and rainfall, the benchmark 13.5 cm remains a canonical value for planning and test questions.

Why Other Options Are Wrong:
23.0, 19.0 cm: High for wheat at kor stage; more suited to paddy-like conditions.17.5, 12.0 cm: Not the best-fit standardized value; 12.0 cm is often slightly low.

Common Pitfalls:

• Using rice kor depths for wheat.
• Not adjusting for very light/sandy soils where percolation is high (field judgment still required).

Final Answer:
13.5 cm