Nitrogen supply modulates nitrogen remobilization and nitrogen use of wheat under supplemental irrigation in the North China Plain.

ABSTRACT: Excessive nitrogen (N) input and irrigation exacerbate N leaching in winter wheat production in the North China Plain (NCP). To explore the optimal N for better N remobilization and higher N utilization of wheat under water-saving irrigation will be conductive to less environmental contamination. A field experiment was conducted at 300 (N₃₀₀), 240 (N₂₄₀), 180 (N₁₈₀), and 0 (N₀) kg N ha^-1 of N application under supplemental irrigation (SI) that brought the relative soil water content (RSWC) to 70% at jointing and 65% at anthesis. Compared with N₀, N₁₈₀ improved the free amino acid content in the flag leaf and grain after anthesis, dry matter and plant N accumulation at maturity, N translocation amount of vegetable organs and its contribution to grain from anthesis to maturity. Compared to N₂₄₀ and N₃₀₀, N₁₈₀ increased the N translocation efficiency of vegetable organs, and reduced the soil NO₃-N residue in the 60-180 cm soil layer, which contributing to no significant reduction in grain yield and grain protein yield, but higher grain N recovery efficiency (^GRE_N), N recovery efficiency (RE_N), and N partial factor productivity (PFP_N). Positive relationships were found between leaf N translocation efficiency and grain yield, grain protein yield, PFP_N, ^GRE_N, and RE_N. Therefore, N₁₈₀ is appropriate to obtain a steady grain yield over 7.5 t ha^-1 for at least 2 years under SI based on RSWC in the NCP.

SUBMITTER: Zheng X 

PROVIDER: S-EPMC7039916 | biostudies-literature |

REPOSITORIES: biostudies-literature