Nearly half of U.S. stream miles are in poor biological condition, primarily due to nutrient pollution by nitrogen (N) and phosphorus (P). One of the most predominant sources of this nutrient pollution is from agricultural run-off. Macroinvertebrate communities are particularly susceptible to nutrient pollution, and associated physiological or community shifts may alter macroinvertebrate nutritional composition, with food web and ecosystem-level implications. To investigate how agricultural N and P pollution influences the organismal stoichiometry and macronutrient composition of macroinvertebrates, we sampled eight headwater streams in the Arkansas River Valley along a land-use gradient ranging from <1% to 72% pasture/hay during May/June 2023. We measured the C:N, C:P, and N:P ratios, delta-13C and delta-15N, %lipid, and %protein composition of macroinvertebrates. Preliminary results consistently showed significant strong, positive correlations (rho2>0.85, p<0.05) between %pasture/hay coverage and delta-13C and delta-15N among Plecoptera, Coleoptera, and Isopoda. Trichopterans showed no significant correlation between %pasture/hay and delta-13C or delta-15N, although there was a strong positive trend with delta-15N (rho2=0.71, p=0.07). Responses of C:N, C:P, N:P, %lipid, and %protein were highly Order-specific. Only Trichoptera showed a significant, strong negative correlation between %pasture/hay and C:N (rho2= -0.93, p<0.05). Plecoptera demonstrated an insignificant but moderately positive trend between %pasture/hay and C:N (rho2=0.62, p=0.10), and a positive trend between %pasture/hay and %protein (rho2=0.64, p=0.12). Coleoptera demonstrated insignificant but interesting non-linear trends between %pasture/hay and C:P, C:N, and N:P (all rho2=-0.50, p=0.25). Isopoda demonstrated an insignificant but moderately positive trend between %pasture/hay and %protein (rho2=0.48, p=0.23) and insignificant but negative trends between %pasture/hay and C:P (rho2=-0.57, p=0.14) and N:P (rho2=-0.48, p=0.23). Agricultural nutrient pollution may differentially alter the elemental and macronutrient composition and quality of macroinvertebrates, potentially driving subsequent changes throughout stream food webs. Future analyses will investigate Family-level relationships between agricultural land-cover and macroinvertebrate and basal resource stoichiometry, and Family-level and potential functional feeding group relationships between organismal stoichiometry and macronutrient composition.