Intercropping Maize with Leguminous Green Manure Enhances N Use Efficiency and Reduces Chemical Fertilizer Use

Strategic Insights -

Intercropping maize with leguminous green manure is a sustainable agricultural practice that enhances crop yields while reducing chemical nitrogen (N) inputs. A recent study conducted by researchers at Gansu Agricultural University in northwestern China demonstrated that this practice can compensate for the losses in grain yield and N uptake caused by reduced N supply. The study involved a field experiment with a split-plot design, where maize-common vetch intercropping (IM) and sole maize (SM) were tested under different N levels, including zero N application, a 25% reduction from the traditional chemical N supply, and the traditional chemical N supply.

Key Takeaways:

  • Intercropping maize with leguminous green manure can enhance N assimilation and uptake in maize, effectively replacing chemical fertilizer with leguminous green manure.
  • This practice improves N use efficiency and maintains stable yields in the maize-based intercropping system.
  • The integrated system involving maize-leguminous green manure intercropping and reduced N supply enhances N translocation from maize vegetative organs to grains.
  • Nitrate reductase and glutamine synthetase activities in maize leaves increased year by year, reaching values of 16.1%, 21.3%, and 25.5% in 2019, 2020, and 2021, respectively.
  • The study suggests that intercropping maize with leguminous green manure under reduced chemical N input can enhance N use efficiency and stabilize yields in the maize-based intercropping system.
  • The researchers aim to evaluate the impacts of intercropping maize with leguminous green manure on grain yield and N utilization under reduced N-fertilization conditions.

Statistics:

  • The study involved a field experiment with a split-plot design carried out in northwestern China from 2018 to 2021.
  • The main plots consisted of two cropping systems: maize-common vetch intercropping (IM) and sole maize (SM).
  • The subplots had three N levels: zero N application (N0, 0 kg ha-1), a 25% reduction from the traditional chemical N supply (N1, 270 kg ha-1), and the traditional chemical N supply (N2, 360 kg ha-1).
  • Nitrate reductase and glutamine synthetase activities in maize leaves increased from 16.1% in 2019 to 25.5% in 2021.

Sources:

  • Gansu Agricultural University Researchers Have Published New Data on Integrative Agriculture (Intercropping maize with leguminous green manure can compensate for the losses in grain yield and N uptake caused by a reduced N supply). Agriculture Week. July 10, 2025; p 191.
  • Intercropping maize with leguminous green manure can compensate for the losses in grain yield and N uptake caused by a reduced N supply. Journal of Integrative Agriculture, 2025,24(7):2826-2840.