Question

Choose the correct sequence for irrigation scheduling of crops using climatological approach. A. Reference ET, Crop Coefficient, Climate data, Crop ET, Irrigation efficiency, Irrigation time B. Crop ET, Reference ET, Crop Coefficient, Irrigation efficiency, Climate data, Irrigation time C. Irrigation time, Climate data, Crop coefficient, Reference ET, Crop ET, Irrigation efficiency D. Climate data, Reference ET, Crop coefficient, Crop ET, Irrigation efficiency, Irrigation time Choose the correct answer from the options given below:

• A. B
• B. D
• C. A
• D. C

Hint:

Important irrigation scheduling sequence: \[ \boxed{ \text{Climate data} \rightarrow ET_0 \rightarrow K_c \rightarrow ET_c \rightarrow \text{Efficiency} \rightarrow \text{Irrigation time} } \] Remember: \[ ET_c = K_c \times ET_0 \] Memory Trick: \[ \boxed{ \text{“Climate first, irrigation last”} } \]

Answer 1

The Correct Option is B

Concept: Irrigation scheduling is the scientific process of determining:
• When irrigation should be applied
• How much water should be applied In the climatological approach, irrigation scheduling is based on atmospheric demand and crop water requirement. The procedure generally involves:
• Collection of climatic data
• Estimation of reference evapotranspiration (\(ET_0\))
• Application of crop coefficient (\(K_c\))
• Determination of crop evapotranspiration (\(ET_c\))
• Adjustment for irrigation efficiency
• Estimation of irrigation duration or irrigation time The sequence must follow a logical hydrological and irrigation engineering procedure.

Step 1: Understanding the role of climate data. The first step in climatological irrigation scheduling is obtaining:
• Temperature
• Humidity
• Wind speed
• Solar radiation
• Sunshine duration These parameters are collectively known as: \[ \boxed{\text{Climate data}} \] Without climatic data, evapotranspiration cannot be estimated. Therefore: \[ \boxed{\text{Climate data must come first}} \]

Step 2: Estimating Reference Evapotranspiration (\(ET_0\)). Using climate data, reference evapotranspiration is calculated through methods such as:
• Penman-Monteith method
• Blaney-Criddle method
• Radiation method Thus: \[ \boxed{ \text{Climate data} \rightarrow \text{Reference ET} } \]

Step 3: Applying Crop Coefficient (\(K_c\)). Different crops consume different amounts of water. To convert reference ET into crop ET, crop coefficient is used: \[ ET_c = K_c \times ET_0 \] Thus after calculating reference ET, we use: \[ \boxed{\text{Crop coefficient}} \]

Step 4: Calculating Crop Evapotranspiration. Using: \[ ET_c = K_c \times ET_0 \] we determine: \[ \boxed{\text{Crop ET}} \] Crop ET represents actual crop water requirement.

Step 5: Considering Irrigation Efficiency. Water losses occur due to:
• Conveyance losses
• Seepage losses
• Application losses Therefore actual irrigation requirement becomes: \[ \text{Gross irrigation requirement} = \frac{\text{Net irrigation requirement}} {\text{Irrigation efficiency}} \] Hence irrigation efficiency is considered after crop ET estimation.

Step 6: Determining irrigation time. Finally, after knowing:
• Required water depth
• Flow rate
• Efficiency we calculate: \[ \boxed{\text{Irrigation time}} \] Thus the complete sequence becomes: \[ \boxed{ \text{Climate data} \rightarrow \text{Reference ET} \rightarrow \text{Crop coefficient} \rightarrow \text{Crop ET} \rightarrow \text{Irrigation efficiency} \rightarrow \text{Irrigation time} } \]

Step 7: Comparing with the given options. Option (A): Starts with Reference ET before climate data. Incorrect sequence. Hence: \[ \boxed{\text{Option (A) is incorrect}} \] Option (B): Matches the correct sequence exactly. Hence: \[ \boxed{\text{Option (B) is correct}} \] Option (C): Begins with irrigation time which should come last. Hence: \[ \boxed{\text{Option (C) is incorrect}} \] Option (D): Incorrect arrangement. Hence: \[ \boxed{\text{Option (D) is incorrect}} \] Final Conclusion: The correct sequence for irrigation scheduling using climatological approach is: \[ \boxed{ \text{Climate data} \rightarrow \text{Reference ET} \rightarrow \text{Crop coefficient} \rightarrow \text{Crop ET} \rightarrow \text{Irrigation efficiency} \rightarrow \text{Irrigation time} } \] Hence the correct answer is: \[ \boxed{(B)\ D} \]