Mechanical tillage costs

Herbicides reduce mechanical tillage costs (2 ). Each year in the United States, 250 billion tons of soil are moved, much of it several times, in tillage and cultivation operations. This amount of soil would make a ridge 100 feet high and one mile wide from New York to San Francisco. The movement of this soil each year is the world s largest materialhandling operation. At least one-half of this soil-moving function is practiced solely for the control of weeds. 

An annual estimated cost of approximately 938,835,000 is required for labor and equipment to apply 204.5 million kilograms of herbicides to 147.6 million hectares of cropland in the United States (Table IV). Mechanical tillage to control weeds between cropping seasons and interrow tillage of crops has been used for centuries as a very effective method of weed control. Approximately 50% of all tillage between crops is done to control weeds. The number of cultivations required for effective weed control within a row crop varies from two to five during a cropping season. 

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