Nitrogen Management Strategies to Improve Crop Performance, Recovery Efficiency and Their Relationship with Physiological Indices in Dry Direct-Seeded Rice

Hafeez ur Rehman*, Imran Ali, Fiaz Ali, Masood Iqbal Awan, Abdul Wakeel, Muhammad Farooq, Mubshar Hussain

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Nitrogen (N) recovery efficiency in dry-direct seeded rice (DSR) is less than 30%, hence, requires special consideration. Nitrogen management strategies such as splitting N in appropriate dose and application time synchronize with crop demand to improve nitrogen use efficiency (NUE). This two-year field study compared two- and three- N splits top-dressed at different crop stages using 80, 120 and 160 kg ha− 1 with 0 kg ha− 1 as control in dry DSR. Results showed that two N- splits performed similar as three-splits for agronomic, quality and NUE traits including SPAD-chlorophyll and normalized difference vegetation index (NDVI). Similar and higher straw and grain yields including harvest index was found for 120 and 160 kg N ha− 1 that was attributed to reduced spikelet sterility (24–29%), improved filled kernels (16–19%) and productive tillers (21–31%). Two- N splits at 160 kg ha− 1 resulted in higher net income and benefit: cost ratio (BCR) of dry DSR. Improved plant N status reduced kernel chalkiness and improved kernel length, proteins contents and water absorption ratio. Agronomic and physiological efficiency reduced with increasing N application while recovery efficiency (31–58%) was improved. Strong association of NDVI with leaf N, and total N uptake with sufficiency index (SI) and grain yield indicated that rice crop achieved optimal N concentration to support growth during active tillering period. Thus, additional N applied in three splits might be reduced to economize N use and SI can be used to predict and optimize the N schedule during panicle initiation or heading stages to reduce the sink limitation.

Original languageEnglish
JournalInternational Journal of Plant Production
Publication statusAccepted/In press - 2023


  • Kernel chalkiness
  • Nitrogen use efficiency
  • Normalized difference vegetation index
  • SPAD-chlorophyll
  • Spikelet sterility
  • Total N uptake

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Plant Science

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