Test Your Knowledge on Soil Conditioners

Key Points:

• Soil conditioners are added to soil to improve its physical and fertility qualities, and are often thought of as a subset of soil amendments.
• A wide variety of materials have been described as soil conditioners, including biochar, compost, manure, lime, and sulfur.
• Polyacrylamides, such as Broadleaf P4 and Swell-Gel, are used for horticultural and agricultural purposes, as well as for erosion control at construction sites.
• Soil conditioners improve soil structure, add nutrients such as carbon and nitrogen, and increase the cation exchange capacity (CEC) of soils.
• They also improve water retention in dry, coarse soils and can be used to adjust the pH of the soil.
• Synthetic soil conditioners, such as polyacrylonitrile, were introduced in the 1950s but were found to be phytotoxic due to their high acrylamide monomer residue.
• Soil conditioners can be applied in a number of ways, but soil testing should be performed prior to application to determine which conditioners are appropriate.
• Over-application of some soil amendments can cause ecological problems, as excess nutrients can be harmful to plant health and water quality.