The researchers studied nitrogen and phosphorus transportation in the Yellow River over the past few decades. They found that nitrogen levels increased over 40 years but decreased in the late 1990s due to river desiccation. Phosphorus levels fluctuated without a clear trend and also decreased in the late 1990s. Nitrogen transportation was mainly influenced by population and fertilizer use, while phosphorus transportation was linked to soil erosion from the Loess Plateau. This information can help manage nutrient pollution in the river and surrounding areas.