Dataset on the contents of 10 elements in litter and soil of Larix gmelinii secondary forest under nitrogen addition in the Nanweng River National Nature Reserve, Heilongjiang Province

The experiment employed a completely randomized block design with three blocks, each containing four 20 m × 20 m plots corresponding to four nitrogen addition treatments: 0, 25, 50 and 75 kg N·hm⁻²·a⁻¹, representing control, low nitrogen, middle nitrogen and high nitrogen treatments, respectively.

The nitrogen addition experiment began in 2011, and samples were collected in August 2024. Litter samples were taken from the undecomposed layer and the decomposed layer, while soil samples were collected from the 0–10 cm and 10–20 cm soil layers. After pretreatment including oven-drying, grinding, and sieving, the contents of ten elements—carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), manganese (Mn) and zinc (Zn)—were determined.