A much-touted policy tool to reduce nutrient pollution from livestock agriculture is the nutrient management plan (NMP). NMPs can be voluntary or required, and oblige farms to match the nutrients applied as manure or commercial fertilizer with the absorptive capacity of land and crops. However, little research examines whether these plans are implemented, even if farms have records of having plans. In this paper we use nationally-representative Agricultural and Resource Management Survey (ARMS) data on hog producers to compare the nutrient application practices of farms with and without NMPs to see whether having an NMP makes a farm less likely to over-apply nutrients, as well as to adopt other nutrient management practices. We also examine whether the effect of having an NMP on nutrient management is strengthened by state NMP requirements, proximity to urban areas, regional nutrient balance, and watershed water quality oversight. Our preliminary findings suggest that NMPs are effective in encouraging nutrient testing but not in reducing over application of nutrients to farmland; they have the most effect in states with more stringent regulation.