Although there are many motivations for choosing to intercrop—risk reduction, soil health, pest management—strong production remains a priority. Without a means to measure effectiveness, you can't objectively evaluate outcomes or adjust practices accordingly.
Several established metrics exist for evaluating intercropping systems. Each answers different questions about system performance.
Land Equivalent Ratio (LER)
The Land Equivalent Ratio is the most common and fundamental intercropping metric. It answers the question: how much land would you need, using monocultures, to produce the same output as your intercropped system?
LER = (Intercrop Yield A / Monoculture Yield A) + (Intercrop Yield B / Monoculture Yield B)
Interpretation:
- LER greater than 1.0: Advantageous pairing—intercropping produces more than equivalent monoculture area
- LER equal to 1.0: Neutral—intercropping produces the same as monocultures
- LER less than 1.0: Disadvantageous pairing—monocultures would be more productive
An LER of 1.25 means you would need 25% more land to produce the same output using separate monocultures. This is a meaningful efficiency gain.
LER is useful for measuring maximum production, comparing crop combinations, and evaluating agronomic practices. To calculate it properly, you need monoculture comparison plots—ideally side-by-side with your intercropped area under the same conditions.
Income Equivalence Ratio (IER)
The Income Equivalence Ratio uses a similar approach to LER but measures yield in terms of net income rather than physical production.
IER accounts for the reality that different crops have different market values. A combination might have a low LER but high IER if the intercropped system favors a higher-value crop.
Limitation: IER fluctuates with crop prices, so it may not accurately gauge long-term productivity. A combination that looks good when prices favor one crop may look poor when prices shift.
Competitive Ratio (CR)
Using LER data, the Competitive Ratio measures how competitive the two (or more) crops are with each other, accounting for their sowing proportions.
This helps you understand whether one crop is dominating at the expense of another. A well-balanced intercrop should show relatively equal competitive ratios—both crops contributing proportionally to the system's output.
If one crop has a much higher CR than another, you might adjust:
- Planting ratios (more of the less competitive crop)
- Spacing (give the weaker competitor more room)
- Timing (plant the weaker competitor earlier)
- Cultivar selection (choose more competitive varieties of the weaker crop)
Monetary Advantage Index (MAI)
The Monetary Advantage Index provides an indication of the economic advantage of an intercropping system in actual currency terms rather than ratios.
While LER tells you the system is 25% more land-efficient, MAI tells you that translates to $X more income per acre. This makes it easier to compare intercropping benefits against the additional costs (labor, management complexity) it requires.
Area Time Equivalent Ratio (ATER)
The Area Time Equivalent Ratio incorporates time by accounting for the duration of crop growth in the evaluation.
This matters for relay intercropping where crops occupy the land for different periods. A system might look efficient by LER but less impressive when you account for the total time the land is occupied.
ATER is particularly useful when comparing systems with different growing season lengths or when evaluating whether relay intercropping is more efficient than sequential monocultures.
Practical Measurement Approach
For most operations, start with LER as your primary metric:
- Establish comparison plots: Plant monocultures of each component crop alongside your intercropped area, under identical conditions
- Measure yields carefully: Harvest and weigh each crop separately from both intercropped and monoculture plots
- Calculate LER: Use the formula to determine whether your combination is advantageous
- Track over multiple seasons: One season's results may not represent long-term performance
Add IER and MAI calculations when you want to understand economic implications. Use CR when you need to fine-tune crop balance. Apply ATER when time efficiency matters for your system.
The Stack 4 Connection
Measurement is central to Stack 4 implementation. Without data, you can't know whether sustainable practices are actually delivering value.
These intercropping metrics connect directly to the broader Five Stacks approach:
- They provide objective evidence for Stack 1 certification claims
- They generate the baseline data Stack 2 requires for efficiency evaluation
- They help identify circular value opportunities in Stack 3
- They verify that Stack 4 practices are working as expected
- They build the data foundation for Stack 5 storytelling
Start measuring now—even imperfectly—so you have data to work with as you refine your system.
Ready to measure what matters?
Effective intercropping requires measurement. These metrics help you evaluate whether your practices are delivering the benefits you expect.
Stack 4 focuses on sustainable practices that generate measurable returns. The framework helps you implement practices systematically and verify results with data—turning assumptions into evidence.
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