N deficiency is seen as relatively uniform yellowing of lower (older) leaves.

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Wheat with yellowing lower leaves due to nitrogen deficiencyA field of wheat with dark green plants on the left and light green plants due to nitrogen deficiency on the rightWheat with yellowing lower leaves from nitrogen deficiency caused by drowningA field of wheat with patches of light green or yellow plants due to nitrogen deficiencyWheat with yellowing lower leaves from nitrogen deficiencyBarley with yellowing lower leaves from nitrogen deficiencyOne healthy barley leaf that is dark green and long, one barley leaf with moderate nitrogen deficiency that is light green, and one nitrogen deficient barley leaf that is short and yellowRows of corn plants in a field with chlorotic lower leavesYoung corn plants with yellowing bottom leaves due to nitrogen deficiency A person holding a canola plant with a yellowing mature leaf due to nitrogen deficiencyCanola plants at the rosette stage with yellowing lower leaves from nitrogen deficiencyPea with light green lower leaves due to nitrogen deficiencyBean with light green leaves due to nitrogen deficiencyPepper plant with light green mature leaves due to nitrogen deficiencyPoppy plants with light green or yellow lower leaves due to nitrogen deficiencyMint with chlorotic leaves due to nitrogen deficiencyRaspberry with light green or yellow leaves due to nitrogen deficiencyA pasture with light green grass from nitrogen deficiencySunflowers in a field with thin stems and light green, yellowing older leaves due to nitrogen deficiencyPotato with yellow older leaves due to nitrogen deficiency

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