Optimizing nitrogen-fertilizer management by using RZWQM2 with consideration of precipitation can enhance nitrogen utilization on the Loess Plateau

Dianyuan Ding, Zijie Yang, Lihong Wu, Ying Zhao, Xi Zhang, Xiaoping Chen, Hao Feng, Chao Zhang, Ole Wendroth

Research output: Contribution to journalArticlepeer-review

Abstract

Crop yields are related to N fertilizer management, and also depend on local precipitation. Varying precipitation levels with long-term meteorological data have not been considered to optimize nitrogen (N) strategies in previous studies on the Loess Plateau of China. In this study, Root Zone Water Quality Model 2 (RZWQM2) was calibrated and validated using data from multi-year experiments and used to assess and optimize N management strategies for winter wheat cultivation. Results showed that the basal dressing fertilizer with 120 kg N ha-1 together with the topdressing of 67–77 kg N ha-1 was recommended in regions with 443 mm average annual precipitation. For those with 364 mm and 290 mm average annual precipitation, the basal dressing fertilizer with 90 kg N ha-1 together with the topdressing of 67–77 kg N ha-1 and the basal dressing with 90 kg N ha-1 together with the topdressing fertilizer of 13–23 kg N ha-1 were recommended, respectively. Compared with farmers’ practice (i.e., the single basal dressing), although decreasing the total rate by 12–18 kg N ha-1, the optimized N strategies (i.e., the basal fertilizer together with one-time topdressing) can effectively promote grain N uptake, nitrogen harvest index, and agronomic efficiency of N. It also maintained similar grain yield, evapotranspiration, and crop water productivity. The minimum precipitation threshold was around 300 mm, where the topdressing N fertilizer had little influence on grain yield, evapotranspiration, and grain N uptake. Additionally, the largest advantage of optimized N strategies was saving N fertilizer and reducing the environment footprint of wheat production. However, the crop production under the optimized N strategies was more sensitive to the precipitation variation than that under farmers’ practice. Thus, if climate continues to change following historical data, greater harvest fluctuations are expected under optimized N strategies. To cope with the evolving climate change, optimized N strategies should be integrated with other management measures for smallholder farming households on the Loess Plateau.

Original languageEnglish
Article number108890
JournalAgricultural Water Management
Volume299
DOIs
StatePublished - Jun 30 2024

Bibliographical note

Publisher Copyright:
© 2024 The Authors

Keywords

  • Climate change
  • Dryland farming
  • Meteorological data
  • Split N application
  • Winter wheat

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Water Science and Technology
  • Soil Science
  • Earth-Surface Processes

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