37.4. Methods for Estimating Water Requirement

Try these first

1. 1.

   What does K represent in the Blaney-Criddle Method formula?

   Hint

   Think about factors that affect different crops.

2. 2.

   Name one advantage of the Penman-Monteith Method.

   Hint

   Consider accuracy.

3. 3.

   Which method is considered more accurate for estimating crop water requirements?

   • Blaney-Criddle Method
   • Penman-Monteith Method
   • FAO Modified Penman Method

   Hint

   Think about which method looks at more variables.

4. 4.

   True or False: The Blaney-Criddle Method uses solely empirical data.

   • True
   • False

   Hint

   Consider the type of data used in empirical methods.

5. 5.

   Using the Penman-Monteith method, calculate the water requirement for a crop with net radiation of 20 MJ/m²/day, temperature 25°C, wind speed of 2 m/s, and humidity of 70%. Assume K is 1 for simplicity.

   Hint

   Consider how each variable affects ET.

6. 6.

   Critique the effectiveness of using the Blaney-Criddle Method in arid regions compared to temperate regions.

   Hint

   Focus on climate influence on water requirement estimations.