A sandy soil with 2 percent organic matter would typically require a higher rate of soil-applied herbicide than a clay loam soil with 5 percent organic matter. This statement is:

• A. True
• B. False
• C. It depends on the climate
• D. Only true for certain herbicides

Answer: (B)

A sandy soil with 2 percent organic matter typically does not require a higher rate of soil-applied herbicide compared to a clay loam soil with 5 percent organic matter. In fact, higher organic matter content generally leads to greater adsorption of herbicides, which reduces their availability for plant uptake. So, when applied to clay loam with more organic matter, the herbicides are more likely to bind to the organic matter and be less effective at controlling weeds compared to sandy soils where the organic matter is lower.

As a result, herbicides might need to be applied at a higher rate in soils with higher organic matter to achieve the desired weed control efficacy. The interaction between soil texture, organic matter, and herbicide behavior underscores the importance of soil characteristics in determining herbicide application rates. Therefore, the statement is false.