The maximum value for plant available water is________.

The maximum value for plant available water is determined by the difference between field capacity and wilting point. Field capacity is the amount of water retained in the soil after excess water has drained away and the rate of downward movement has decreased. This represents the maximum amount of water that can be held by the soil, readily available for plant use. On the other hand, wilting point refers to the minimum soil moisture level at which plants can no longer extract water; below this point, plants begin to experience drought stress.

Therefore, the difference between these two values essentially tells us how much water is available for plant uptake, as it represents the range of soil moisture that plants can utilize. This definition is crucial in agronomy and crop management, as it helps determine irrigation needs and overall plant health. Understanding this concept enables farmers and agronomists to manage water resources more efficiently and accordingly adjust practices to optimize crop yield.