Calcium (Ca) Deficiency

Calcium deficiency also affects on root function and can cause iron toxicity. Calcium deficiency is not very common in lowland rice soil and is common in upland rice soil. Causes of calcium deficiency are-

1. Very low amount of absorbable calcium in the soil (sandy soil, acidic soil, degraded soil)

2.  Long-term cultivation of irrigated rice

3.  Excessive application of nitrogen and potassium fertilizer

4.  Excessive application of potassium fertilizer which can depress availability of calcium due to formation of calcium phosphate in alkaline soil

5. Symptoms can be usually visible only under severe calcium deficiency.

How to identify (symptoms)

Plant looks thin when deficiency is not severe. When deficiency is severe, tips of young leaves become white or bleached, rolled and curled.  Necrotic tissue may develop along the lateral margins of leaves and old leaves eventually turn brown and die. Stunting and death of growing point during extreme deficiency.

How to manage

1.  Apply farm yard manure or straw (incorporated or burned) to balance Ca removal in the soil.

 

2.  Where possible, use Single Superphosphate (13−20% Ca) (or) triple superphosphate (9−14% Ca) as a Ca source.