The management decisions of what crops to plant, plant populations, when to irrigation, how much to irrigation, when to apply nitrogen, and how much nitrogen to apply depend in part on the water holding capacity of soils. These management decisions are critical to the long term quantity and quality of Nebraska's water resources. Some of the water in soil is retained and some moves through the soil. It moves readily downward after an irrigation or rain and eventually reaches the ground water. It is taken up by plant roots, moves through the plant to the leaves, and transpires to the atmosphere.
Water also moves toward the soil surface where it evaporates directly into the atmosphere.
Water is retained in or moves through the pore spaces as a result of the size, number, and continuity of the pores. Textural, structural, and organic matter characteristics determine how water is held in soils. This NebGuide provides basic information on how soil holds water. Physical characteristics that influence how soil retains water are outlined. Soil water definitions and soil water retention characteristics of different soil types are discussed.