What does C.E.C. stand for in soil science?

C.E.C. stands for Cation Exchange Capacity in soil science. This is a critical property of soil that indicates its ability to hold and exchange positively charged ions, or cations, such as calcium, magnesium, potassium, and sodium. A high C.E.C. value typically means that the soil has a greater capacity to retain these nutrients, making them more available to plants. This is essential for understanding soil fertility and nutrient management in agriculture and horticulture. Knowing the C.E.C. helps growers determine how much fertilizer to apply and how to amend their soils to enhance plant growth.

The other terms in the options, while they may sound plausible, do not represent the concept defined by C.E.C. In particular, "carbon exchange capacity" does not refer to a recognized property in soil science, "covalent exchange capacity" does not apply since covalent bonding is not involved in the ion exchange process in soils, and "calcium effective capacity" is not a standard term. Understanding C.E.C. and its implications enables better soil management practices and promotes healthy plant growth.