# carbon The carbon content in the aquifer is used to compute a pesticide's Kd value, or distribution coefficient, which is a measure of how tightly a pesticide binds to soil particles. Kd values are important for understanding how pesticides move through the environment. A higher carbon value increases the pesticide partition coefficient Kd, which increases retardation/sorption behavior and generally reduces pesticide movement with aquifer flow and seepage. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://swatplus.gitbook.io/io-docs/introduction-1/aquifers/aquifer.aqu/ptl_n.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.