Tag: Iowa

Download Iowa Soil Drainage Class Maps (gSSURGO)

“Drainage class (natural)” refers to the frequency and duration of wet periods under conditions similar to those under which the soil formed. Alterations of the water regime by human activities, either through drainage or irrigation, are not a consideration unless they have significantly changed the morphology of the soil. Seven classes of natural soil drainage … Continue reading Download Iowa Soil Drainage Class Maps (gSSURGO)

Download Iowa Depth to Water Table Maps (gSSURGO)

“Water table” refers to a saturated zone in the soil. It occurs during specified months. Estimates of the upper limit are based mainly on observations of the water table at selected sites and on evidence of a saturated zone, namely grayish colors (redoximorphic depletions) in the soil. A saturated zone that lasts for less than … Continue reading Download Iowa Depth to Water Table Maps (gSSURGO)

Download Iowa Soil pH Maps (gSSURGO)

Soil reaction is a measure of acidity or alkalinity. It is important in selecting crops and other plants, in evaluating soil amendments for fertility and stabilization, and in determining the risk of corrosion. In general, soils that are either highly alkaline or highly acid are likely to be very corrosive to steel. The most common … Continue reading Download Iowa Soil pH Maps (gSSURGO)

Download Iowa Soil Saturated Hydraulic Conductivity (Ksat) Maps (gSSURGO)

Saturated hydraulic conductivity (Ksat) refers to the ease with which pores in a saturated soil transmit water. The estimates are expressed in terms of micrometers per second. They are based on soil characteristics observed in the field, particularly structure, porosity, and texture. Saturated hydraulic conductivity is considered in the design of soil drainage systems and … Continue reading Download Iowa Soil Saturated Hydraulic Conductivity (Ksat) Maps (gSSURGO)

Download Iowa Soil Clay Content Maps (gSSURGO)

Clay as a soil separate consists of mineral soil particles that are less than 0.002 mm in diameter. The estimated clay content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 mm in diameter. The amount and kind of clay affect the fertility and … Continue reading Download Iowa Soil Clay Content Maps (gSSURGO)

Download Iowa Soil Silt Content Maps (gSSURGO)

Silt as a soil separate consists of mineral soil particles that are 0.002 to 0.05 mm in diameter. In the database, the estimated silt content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 mm in diameter. The content of sand, silt, and clay … Continue reading Download Iowa Soil Silt Content Maps (gSSURGO)

Download 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 Download Iowa Soil Organic Matter Maps (gSSURGO)

Download 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 Download Iowa Available Soil Water Storage Maps (gSSURGO)

Download 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 Download Iowa Soil Available Water Capacity Maps (gSSURGO)