Question

Land equivalent ratio is ______________

• A. The cropping pattern adopted on a farm
• B. The sequential cultivation of crops in a farm
• C. The sum of the fractions of the intercrops, relative to their sole crop yield with different management level
• D. The ratio of land area needed under sole cropping to area of intercropping at the same management level to obtain an equal amount of yield.

Hint:

LER $>$ 1.0 is the goal of every agroforestry system. It proves that the "sum is greater than the parts."

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
The Land Equivalent Ratio (LER) is the most common metric used in agroforestry and intercropping research to evaluate the productivity advantage of mixing different species compared to growing them separately.

Step 2: Key Formula or Approach:
LER is calculated as the sum of the relative yields of the component species:
\[ LER = \frac{Yield\ of\ intercrop\ A}{Yield\ of\ sole\ crop\ A} + \frac{Yield\ of\ intercrop\ B}{Yield\ of\ sole\ crop\ B} \]

Step 3: Detailed Explanation:

• LER essentially asks: "How much land would I need to grow these crops separately to get the same total yield I am getting from my one hectare of intercrop?"

• If LER is exactly 1.0, there is no productivity advantage to mixing the crops.

• If LER is greater than 1.0 ($>$ 1.0), it indicates "over-yielding." For example, an LER of 1.4 means that you would need 1.4 hectares of sole crops to produce as much as 1 hectare of the intercrop/agroforestry mixture. This proves that the mixture is more efficient.

• If LER is less than 1.0, the crops are competing negatively, and it's better to grow them separately.

• In agroforestry, LER helps prove that the combination of trees and crops can capture resources (light, water, nutrients) more effectively than either could alone.

Step 4: Final Answer:
LER is the ratio of land area needed under sole cropping to area of intercropping to obtain equal yield.