Does excess nitrate resulted in calcium deficiency?




many aquarists have reported that some sensitive species of aquatic plants, e.g. Rotala macrandra, showed growth stunt or distorted new leaves when nitrate levels were too high. I know some people don't agree with me, but I did have the same experience on Rotala macrandra. Recently I have noticed a paragraph here:

"Calcium (Ca) deficiency is a common disorder of plants on acidic soils, but more usually caused by unavailability rather than a shortage. This may be due to water shortages, which slow the transportation of calcium to the plant, or can be caused by excessive usage of potassium or nitrogen fertilisers."

Wow, excessive usage of K or N fertilizers may resulted in calcium deficiency!

I did an internet search and found an interesting article (65 years ago!) "EFFECT OF THE FORM OF THE AVAILABLE NITROGEN ON THE

"In the absence of calcium much better growth was made with urea than with nitrates. With urea the calcium deficiency symptoms were much delayed, and when they became evident they were very much less severe."

Therefore I assume that nitrate may be a better nitrogen source for the plant, however, calcium supplement would be indispensable to alleviate the calcium deficiency in the plant.

Like to hear more comments on that. Thanks.

Tom Barr

Staff member
Jan 23, 2005
Re: Does excess nitrate resulted in calcium deficiency?

In acidic soils, these are Ca lacking..........
In absense of Ca.
If you add a lot of N and K, then Ca will be used up, therefore you likely will need to add Ca Ferts otherwise the soils will get depeleted over time.

In many soils, unless the farmer added more Ca relative to N and K, it'll get used up faster.

Also, how many aquatic plants have a water shortage?

What is going in your tank with respect to the R mac, adding NO3 increased uptake of CO2. No N, no enzymes that take up CO2.

Note, NO3- and Ca++ are quite different and use very different transport and uptake system.

Ca++ is the signal cation used for communications.
NO3- is a building protein block.
They have different charges.

The issue in soil is pronounced due to the lack of additions of Ca, tap and folks that have decent GH's never have Ca issues, it's something else.

CO2 is typically the case with R mac, I've seen this 100 times.

Adding more N and K drives more growth which places more demand on CO2.

It's a down stream effect.

Tom Barr