Eutrophication beyond that of the watershed, cooperation between different organizations is necessary to prevent the intrusion of contaminants that can lead to eutrophication. Agencies ranging from state governments to those of water resource management and non-governmental organizations, going as low as the local population, are responsible for preventing eutrophication of water bodies. In the United States, the most well known inter-state effort to prevent eutrophication is the Chesapeake Bay. Soil Nitrogen Testing (N-Testing) is a technique that helps farmers optimize the amount of fertilizer applied to crops. By testing fields with this method, farmers saw a decrease in fertilizer application costs,
Plant to plant communication via mycorrhizal networks be related; therefore, kin selection might improve inclusive fitness and explain why a plant might support a fungus that helps other plants to acquire nutrients. Receipt of defensive signals or cues from an infested plant would be adaptive, as the receiving plant would be able to prime its own defenses in advance of an attack by herbivores. Allelopathic chemicals transferred via CMNs could also affect which plants are selected for survival by limiting the growth of competitors through a reduction of their access to nutrients and light. Therefore, transfer of the different classes of infochemicals might prove adaptive for plants.