Alfisols Jack Gillund

What constitutes an Alfisol? Typically found under hardwood forested areas or mixed vegetation areas that have average amounts of moisture. Parent material is mostly glacial. These are moderately leached soils. These soils are naturally productive soils and are good for varying agricultural uses. Alfisols generally fall under the classification of an ochric epipedon, meaning they are lower in organic conent.

A breakdown of the horizons of an Alfisol. Alfisols have healthy, thin O and A horizons because they are generally formed under hardwood forests. Leaf litter contributes greatly to fertility. Alfisols have a pronounced E horizon because of the eluviation of aluminum and iron suspended in clay particles. In the B horizons, clay has accumulated and is an Argillic horizon, meaning it has a “clay skin”. Soil is considered pale.

Where can you find Alfisols? Alfisols are relatively common and cover roughly 10% of earths non-ice covered surface. Alfisols make up about 14% of US soils. Formed either from glacial parent material or under mixed vegetation like in Texas or California. We saw them on our field trip in Whitewater when we saw a pronounced E horizon. Also, the Lester loam is an Alfisol.

Global soils. Alfisols make up about 10% of earths soils. Alfisols are commonly formed under forest cover. Primary uses of these soils globally are agriculture and forestry. Soils are typically found in climates similar to our own here in Minnesota.

Minnesota soils. Alfisols make up a good amount of Minnesota soils and are found under primarily hardwood forests. Moderately weathered soils, leaf litter provides organic matter. These are fertile soils that host forests or are cultivated for agriculture. These soils are moderately wet, but can dry out in droughts.

Lester loam. Thin O and A horizons. Prominent E horizon. Relatively pale B horizons with RMFs appearing as you move down the profile. Lots of clay in the B horizons.

Suborders of Alfisols. Aqualfs Cryalfs These are wet forest soils. Commonly found in the basins of glacial lakes, such as glacial lake Aggasiz here in the U.S. Typically these soils are either forested, or have sustained a forest in the past. Cryalfs This soil suborder occurs at high elevations and in very cold climates. These soils host forests primarily.

More soil suborders. Udalfs Ustalfs Udalfs are forested soils. These soils support hardwood forests across the state. Fun fact: some of the largest red and white pine trees were found growing in this soil suborder. Ustalfs This soil suborder is characterized by a pronounced wet and dry season cycle Grasslands and shrublands are supported. Used primarily for grazing and some agriculture.

More soil suborders. Xeralfs This soil suborder is characterized by very wet winters and dry summers. Various types of shrubs and grasses are supported. Used for agriculture, grazing, or forestry purposes.

Questions?

Sources https://www.soils.org/discover-soils/soil-basics/soil-types/alfisols https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/class/maps/ ?cid=nrcs142p2_053591 http://geo.msu.edu/extra/geogmich/alfisols.html https://www.sciencedirect.com/topics/agricultural-and-biological- sciences/alfisol https://en.wikipedia.org/wiki/Alfisol https://extension.umn.edu/soil-management-and-health/soil-orders-and- suborders-minnesota