Question

In the field layout of a randomized block design, the blocks are formed in the direction :

• A. parallel to fertility gradient
• B. perpendicular to fertility gradient
• C. diagonally to fertility gradient
• D. in a random manner

Hint:

Remember the golden rule of blocking in RBD:
- Plots within a block \(\implies\) Homogeneous.
- Blocks \(\implies\) Perpendicular to the fertility gradient.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The Randomized Block Design (RBD) uses the principle of local control to reduce experimental error.
By grouping experimental units into homogeneous blocks, we can isolate the variation between blocks from our treatment comparisons.

Step 2: Detailed Explanation:
For a block to be effective, the experimental units within that block must be as homogeneous as possible, while the variation between different blocks is maximized.
In agricultural fields, soil fertility typically changes along a specific path, known as the fertility gradient.
To ensure that all plots within a single block have similar fertility levels:
- The blocks must be laid out perpendicular (at a right angle) to the direction of the fertility gradient.
This ensures that the fertility change occurs between blocks, rather than within a block.
If the blocks were aligned parallel to the fertility gradient, each block would contain the full range of fertility variation, violating the requirement of within-block homogeneity and increasing the experimental error.
Thus, perpendicular alignment is the correct and standard field layout practice.

Step 3: Final Answer:
The correct option is (B).