1. What is the Irrigation Water Requirement Equation?

The Irrigation Water Requirement (IN) equation calculates the amount of water needed for crops by subtracting effective precipitation from evapotranspiration. It helps farmers optimize water use and plan irrigation schedules efficiently.

2. How Does the Calculator Work?

The calculator uses the Irrigation Water Requirement equation:

Where:

• \( IN \) — Irrigation need (mm)
• \( ET \) — Evapotranspiration (mm)
• \( Pe \) — Effective precipitation (mm)

Explanation: The equation accounts for water lost through evapotranspiration and subtracts the water provided by rainfall to determine additional irrigation needs.

3. Importance of Irrigation Calculation

Details: Accurate irrigation calculation is crucial for water conservation, crop health, and maximizing agricultural productivity while minimizing water waste.

4. Using the Calculator

Tips: Enter evapotranspiration and effective precipitation values in millimeters. Both values must be non-negative numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is evapotranspiration (ET)?
A: ET is the sum of water evaporation from soil and plant transpiration, representing total water loss from a crop field.

Q2: What is effective precipitation (Pe)?
A: Effective precipitation is the portion of rainfall that is actually available to plants after accounting for runoff and deep percolation.

Q3: What are typical IN values?
A: Values vary by crop and climate, but typical irrigation needs range from 500-1500 mm per growing season.

Q4: How often should I calculate irrigation needs?
A: Ideally weekly or biweekly during growing season, as ET and precipitation patterns change.

Q5: Are there limitations to this equation?
A: It doesn't account for soil water holding capacity, irrigation efficiency, or crop growth stages which may affect actual water needs.