Nematicides are more difficult to move successfully through fine textured soils (high percent silt or clay) and soils with high levels of organic matter and reports of control failures are more frequent in these types of soils than in sandy soils with low amounts of organic matter. Unfortunately, those conditions which contribute to the success of a nematicide application also contribute to the potential for leaching to groundwater.
Greater caution needs to be exercised when utilizing nematicides in areas with shallow groundwater, high rainfall, or frequent irrigation as these factors increase the potential for groundwater contamination. Application procedures for some products and crops call for delaying irrigation following application in order to maintain the product within the root zone.
Low soil temperatures delay the rate of nematicide decomposition by microbial organisms and allow more time for leaching to occur.