21.3.3. Calculation of the p Factor

Try these first

1. 1.

   What does the p factor adjust in the context of crop irrigation?

   Hint

   Think about the relationship between sunlight and water needs.

2. 2.

   What is the formula for the p factor?

   Hint

   Recall the components involved in the calculation.

3. 3.

   What is the primary purpose of calculating the p factor?

   • To estimate rainfall
   • To estimate crop evapotranspiration
   • To calculate soil moisture

   Hint

   Think about the relationship between sunlight and water needs.

4. 4.

   True or False: The p factor remains constant throughout the year.

   • True
   • False

   Hint

   Consider seasonal changes in daylight hours.

5. 5.

   Calculate the monthly p factor if a given month has 180 daylight hours and is 30 days long, with an annual total of 3600 daylight hours. Discuss how this p factor will affect irrigation planning.

   Hint

   Use the formula and consider seasonal implications.

6. 6.

   If the daylight hours decrease in summer due to unexpected weather conditions, discuss potential strategies farmers could employ to compensate based on p factor calculations.

   Hint

   Think about active adjustments farmers might consider.