An experiment conducted at Rothamsted Research in 1996 examined how varying rates of nitrogen fertilizer affect the yield of forage maize. The study used a randomized complete block design with three blocks, each containing four plots randomly assigned one of four nitrogen application rates: 0, 70, 140, or 210 kg N/ha. For each plot, whole crop forage yield (measured at 100 percent dry matter, in tonnes per hectare) was recorded. The resulting dataset enables analysis of the relationship between nitrogen fertilizer input and maize yield, with blocking incorporated to account for field heterogeneity.