Harvest Your Future: Ace the 2025 Agricultural Engineering Exam!

Field capacity in soil represents the amount of water retained in the soil after excess water has drained away and the rate of downward movement has decreased. Mathematically, it is often expressed in relation to the effective sediment water (SWEff), which indicates how much available water can be used by plants.

The equation where field capacity is denoted as C and is represented as a fraction of SWEff, typically follows established empirical relationships drawn from soil moisture tests and field observations. The division factor in the formula indicates the relationship between SWEff and the capacity of the soil to hold water: dividing by 10 in this case suggests that the effective water component is calibrated against common soil properties and moisture retention characteristics.

This choice reflects commonly accepted practices in agricultural engineering and soil science, indicating that for a given effective water content, field capacity can effectively be approximated. Proper understanding of this relationship is essential for irrigation management and ensuring optimal water availability for crops, directly impacting agricultural productivity.