Blaney-Criddle Formula of Monthly Consumptive Use Calculator

Blaney-Criddle Formula:

\[ Cu = \frac{K \times P}{40} \times (1.8 \times t + 32) \]

Crop Factor (K):

Monthly Percent of Annual Day Light Hours (P):

Mean Monthly Temperature in C (t):

°C

Monthly Consumptive Use (Cu):

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1. What is the Blaney-Criddle Formula?

The Blaney-Criddle formula is an empirical method used to estimate monthly consumptive use of water by crops. It calculates the total amount of water used by plants in transpiration and evaporation from adjacent soils or plant leaves over a specified time period.

2. How Does the Calculator Work?

The calculator uses the Blaney-Criddle formula:

\[ Cu = \frac{K \times P}{40} \times (1.8 \times t + 32) \]

Where:

\( Cu \) — Monthly consumptive use (Centimeter)
\( K \) — Crop factor
\( P \) — Monthly percent of annual day light hours (%)
\( t \) — Mean monthly temperature in Celsius (°C)

Explanation: The formula accounts for crop-specific water requirements, daylight hours, and temperature effects on water consumption.

3. Importance of Monthly Consumptive Use Calculation

Details: Accurate calculation of monthly consumptive use is crucial for irrigation planning, water resource management, and ensuring optimal crop growth while conserving water resources.

4. Using the Calculator

Tips: Enter crop factor (K), monthly percent of annual day light hours (P), and mean monthly temperature in Celsius (t). All values must be valid (K ≥ 0, P ≥ 0).

5. Frequently Asked Questions (FAQ)

Q1: What is the crop factor (K)?
A: The crop factor represents differences in water requirements and the proportion of Epan to be replaced for specific crops.

Q2: How is monthly percent of annual day light hours determined?
A: This is calculated based on the ratio of daylight hours in a specific month to the total annual daylight hours, expressed as a percentage.

Q3: What are typical values for crop factors?
A: Crop factors vary by plant type, growth stage, and climate conditions, typically ranging from 0.4 to 1.2 for most agricultural crops.

Q4: Are there limitations to this formula?
A: The formula may be less accurate in extreme climatic conditions, for non-standard crops, or in regions with significant microclimate variations.

Q5: How is this formula used in irrigation planning?
A: The calculated consumptive use helps determine irrigation water requirements and scheduling to meet crop water needs efficiently.