Editing Marl (section)

===Modern agricultural and aquacultural uses===
Marl continues to be used for agriculture into the 21st century, though less frequently.{{sfn|Morse|Smith|2011}} The rate of application must be adjusted for the reduced content of calcium carbonate versus straight lime, expressed as the calcium carbonate equivalent. Because the carbonate in marl is predominantly calcium carbonate, [[magnesium]] deficiency may be seen in crops treated with marl if they are not also supplemented with magnesium.{{sfn|Warncke|2015}}

Marl has been used in [[Pamlico Sound]] to provide a suitable artificial substrate for [[oyster]]s in a reef-like environment.{{sfn|Morse|Smith|2011}}