Effects of different agricultural treatments on narrowing winter wheat yield gap and nitrogen use efficiency in China

Under the limited cultivated land area and the pursuit of sustainable agricultural development, it is essential for the safety of grain production to study agricultural management approaches on narrowing the winter wheat yield gap and improving nitrogen use efficiency (NUE) in China. In this study, DSSAT-CERES-Wheat Model is used to simulate winter wheat yield under different agricultural treatments, and we analyze yield gaps and NUE with different management scenarios at regional scales and evaluate the suitable approaches for reducing yield gap and increasing NUE. The results show that, the potential of narrowing yield gap ranges 300–900 kg ha–1 with soil nutrients increase, 400–1 200 kg ha–1 with sowing date adjustment and 0–400 kg ha–1 with planting density increase as well as 700–2 200 kg ha–1 with adding nitrogen fertilizer. Contribution rates of management measures of soil nutrients, sowing date adjusting, planting density, and nitrogen fertilizers are 5–15%, 5–15%, 0–4%, and 10–20%, respectively. Difference in nitrogen partial productivity ranges 3–10 kg kg–1 for soil nutrients, 1–10 kg kg–1 for sowing date adjusting, 1–5 kg kg–1 for planting density increase, and –12–0 kg kg–1 for adding nitrogen fertilizers, respectively. It indicates that four treatments can narrow yield gap and improve the NUE in varying degrees, but increasing nitrogen fertilizer leads to the decrease of NUE.