Author: Meyer Bohn

Iowa Soil Water Content – 1/3 Bar Maps (field capacity) [gSSURGO]

Soil water content at -1/3 bar is the amount of soil water retained at a suction tension of 1/3 bar, expressed as a volumetric percentage of the whole soil. Water retained at -1/3 bar is significant in the determination of soil water-retention difference, which is used as the initial estimation of available water capacity for … Continue reading Iowa Soil Water Content – 1/3 Bar Maps (field capacity) [gSSURGO]

Iowa Soil Bulk Density – 1/3 Bar Maps [gSSURGO]

Bulk density, one-third bar, is the oven-dry weight of the soil material less than 2 mm in size per unit volume of soil at water tension of -0.33 bar (-33 kPa), expressed in grams per cubic centimeter. Bulk density data are used to compute linear extensibility, shrink-swell potential, available water capacity, total pore space, and … Continue reading Iowa Soil Bulk Density – 1/3 Bar Maps [gSSURGO]

Iowa Soil Organic Matter Maps [gSSURGO]

Organic matter is the plant and animal residue in the soil at various stages of decomposition. The estimated content of organic matter is expressed as a percentage, by weight, of the soil material that is less than 2 mm in diameter. The content of organic matter in a soil can be maintained by returning crop … Continue reading Iowa Soil Organic Matter Maps [gSSURGO]

Iowa Available Soil Water Storage Maps [gSSURGO]

Available water storage (AWS) is the total volume of water (in centimeters) that should be available to plants when the soil, inclusive of rock fragments, is at field capacity. It is commonly estimated as the amount of water held between field capacity and the wilting point, with corrections for salinity, rock fragments, and rooting depth. … Continue reading Iowa Available Soil Water Storage Maps [gSSURGO]

Iowa Soil Available Water Capacity Maps [gSSURGO]

Available water capacity (AWC) refers to the volume of water held per volume of soil that is available for plant uptake. This water typically occurs between suction levels of ~ -10 kPa (field capacity) and -1,500 kPa (wilting point). The capacity for water storage is given in centimeters of water per centimeter of soil for … Continue reading Iowa Soil Available Water Capacity Maps [gSSURGO]