Nutrition & Root-Zone Chemistry

Nitrogen Assimilation & Remobilization

Nitrogen is incorporated into amino acids, proteins, nucleic acids, chlorophyll-associated systems, and many other compounds. Its forms, uptake, assimilation, and movement within the plant matter more than leaf color alone.

Key concepts

  • Plants absorb inorganic nitrogen primarily in nitrate and ammonium forms under many cultivation systems
  • Assimilation requires energy and carbon skeletons
  • Nitrogen can be remobilized from older tissues under changing supply and developmental demand
  • Excess nitrogen can alter growth and tissue characteristics

What to measure or observe

  • Record fertilizer nitrogen form and concentration context
  • Observe old-versus-new tissue patterns
  • Track growth rate and canopy color over time
  • Review root-zone EC, pH, irrigation, and environmental demand before changing nitrogen

Common mistakes

  • Diagnosing nitrogen status from one leaf
  • Assuming darker green always means better nutrition
  • Ignoring nitrogen form
  • Adding nitrogen without checking overall EC and root function

Visuals this lesson still needs

  • Nitrogen uptake/assimilation pathway
  • Older-to-younger remobilization concept
  • Nitrogen form comparison
  • Nitrogen differential panel