This is a practice employed by armies whereby they take supplies from the countryside wherever the soldiers find them. General Sherman used this practice during fighting in Georgia and South Carolina in the final phases of the Civil War.
The practice you are referring to is called 'scorched earth policy' or simply 'scorched earth.' It involves destroying everything in a given area that might be of use to an advancing enemy, including crops, livestock, and infrastructure like roads and bridges. In addition to General Sherman, other examples of scorched earth practices include Napoleon's invasion of Russia, and during World War II, the Nazis' actions in the Soviet Union.
