Nutrient Management for Soybean Crops

Table 1

Visual symptoms shown by soybean crop during nutrient deficiency.

Nutrient	Visual deficiency syndrome	Citation
Nitrogen	Interveinal chlorosis at lower leaves (light green to yellow), stunted growth, necrosis of older leaves, decrease in nodulation.	[77]
Phosphorous	Dark to bluish-green leaves, interveinal chlorosis at the base of the leaves, growth retardation, spare foliage.	[78]
Potassium	Necrosis at older leaves, small and numerous brown spots with mottling appearance, expanding blotches.	[65]
Sulfur	Upper leaves small, pale yellow-green leaves, chlorotic.; Stems are thin, hard, and elongated appearing plant stunted.	[79]
Calcium	Reduced leaf expansion, primary leaves are cup-shaped when emerged. Brown spots on young leaves, premature leaf senescence occurs at severe deficiency.	Calcium Deficiency in Soybean
Magnesium	Light green to yellow chlorosis in interveinal tissues.; Leaf margins are bent and older leaves and lower leaf affected most.	[65]
Iron	Interveinal chlorosis of upper and new leaves followed by stunting.; With progressive severity, yellow leaves turn to white along the veins.; Brown white necrotic spots occur on the edge of leaves.	[65, 78]
Boron	Yellowing and curling of leaf tips, interveinal chlorosis, and cessation of terminal leaf growth.; Mottled leaves with brown necrotic spots, leaf margins are bent, and internodes are shortened.	[44, 65]
Copper	Necrosis of leaf tips and stem, yellowing of leaves, and stunted growth.; Upper and medium leaves show discoloration starting from veins.	[44, 65]
Cobalt	General yellowing and stunting.	[44]
Manganese	Light green to yellow interveinal areas with distinct green leaf veins.; Necrotic brown spots may develop and premature leaf fall may occur.	[65]
Molybdenum	Similar to N deficiency, leaves are pale green-yellow and twisted.; At progressive deficiency leaf margins, mid-ribs, and interveinal areas become necrotic.	[65]
Chlorine	Can be mistaken with iron deficiency.; Yellow leaves with dark green veins.	[44]
Nickel	Necrosis of leaf tips.; Reduce in size of leaf tissues.	[44]
Zinc	Younger leaves show interveinal chlorosis.; Necrotic brown leaf veins.	[65]