Nitrates

cecilsgarden1958 · April 28, 2008

I had posted this in the discuss forum, but didn't get much results, can you help??

What does the Nitrate-N ppm level mean on a soil test? Mine is way up from last year. Is this a residue from last season or is this actually Nitrogen? Do I still use a nitrogen source this year?

CECIL
-------------
SOIL TEST SPRING 2008
Performed by Penn State University-$9

Soil PH
7.0
Optimum

Phosphate
1040 lb/A
Above Optimum

Exchangeable Cations (meq/100g)
Acidity
0.0

Potash
0.9

Magnesium
2.3

Calicium
22.8

CEC (Cation Exchange Capacity)
18.2

% Saturation of the CEC
Potash
4.8
Optimum

Magnesium
12.8
Above Optimum

Calcium
82.4
Above Optimum

Optional Tests-additional fee
Organic Matter-18.2%

Nitrate-N ppm 104.4

Ammonium Nitrogen mg/kg 6.45 (electrode method)

Soluable Salts-mmhos/cm 0.09

dice · April 28, 2008

From a brief scan with Google, it looks like nitrate ppm
is not used when making a nitrogen recommendation.

The reason is that nitrate ppm is only a test of the nitrogen
that is "immediately available" to plants. That does not
necessarily reflect how much nitrogen will be available over
the course of the season, which also depends on how much
ammonium nitrogen there is, how much nitrogen is made
available by conversion of the ammonium nitrogen to nitrates,
how much nitrogen is bound up in organic matter that will
be released by bacteria, fungi, and worms as the season
warms up, and so on.

So all that really tells you is that your nitrate nitrogen is
high enough to get your plants off to a fast start.

I would add only compost to a soil that tested like yours.
Then I would keep an eye on the plants and see if they
show any nitrogen deficiency symptoms on the leaves
( http://4e.plantphys.net/article.php?ch=5&id=289 ; has an
explanation down below in the pictures specifically for
nitrogen deficiency ).

If they do show lower leaves turning yellow, do a test with
some fish emulsion watered in on one plant. If the yellow
leaves immediately start to turn green, they probably all
need some more nitrogen, so scatter some blood meal around
under them and give them all a watering with fish emulsion.

Odds are, though, that your soil has plenty of nitrogen for
tomato plants, and breakdown of compost over the season
will resupply what the tomato plants use up.

(If you do use some fish, you might put out a raccoon trap
with some cat food in it at the same time. Fish attracts
raccoons.)

cecilsgarden1958 · April 28, 2008

Alias: Thanks for the reply. Lots of good insight there. I appreciate it. Sounds like everything is okay to plant, then. I was worried that the nitrate level was to high and would burn. Again, I appreiciate the reply. Thanks.

CECIL

April 28, 2008	#1
cecilsgarden1958 Tomatovillian™ Join Date: May 2006 Location: swPA Posts: 629	Nitrates I had posted this in the discuss forum, but didn't get much results, can you help?? What does the Nitrate-N ppm level mean on a soil test? Mine is way up from last year. Is this a residue from last season or is this actually Nitrogen? Do I still use a nitrogen source this year? CECIL ------------- SOIL TEST SPRING 2008 Performed by Penn State University-$9 Soil PH 7.0 Optimum Phosphate 1040 lb/A Above Optimum Exchangeable Cations (meq/100g) Acidity 0.0 Potash 0.9 Magnesium 2.3 Calicium 22.8 CEC (Cation Exchange Capacity) 18.2 % Saturation of the CEC Potash 4.8 Optimum Magnesium 12.8 Above Optimum Calcium 82.4 Above Optimum Optional Tests-additional fee Organic Matter-18.2% Nitrate-N ppm 104.4 Ammonium Nitrogen mg/kg 6.45 (electrode method) Soluable Salts-mmhos/cm 0.09 __________________ Hybrids Rule, Heirlooms Drool!

April 28, 2008	#2
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	From a brief scan with Google, it looks like nitrate ppm is not used when making a nitrogen recommendation. The reason is that nitrate ppm is only a test of the nitrogen that is "immediately available" to plants. That does not necessarily reflect how much nitrogen will be available over the course of the season, which also depends on how much ammonium nitrogen there is, how much nitrogen is made available by conversion of the ammonium nitrogen to nitrates, how much nitrogen is bound up in organic matter that will be released by bacteria, fungi, and worms as the season warms up, and so on. So all that really tells you is that your nitrate nitrogen is high enough to get your plants off to a fast start. I would add only compost to a soil that tested like yours. Then I would keep an eye on the plants and see if they show any nitrogen deficiency symptoms on the leaves ( http://4e.plantphys.net/article.php?ch=5&id=289 ; has an explanation down below in the pictures specifically for nitrogen deficiency ). If they do show lower leaves turning yellow, do a test with some fish emulsion watered in on one plant. If the yellow leaves immediately start to turn green, they probably all need some more nitrogen, so scatter some blood meal around under them and give them all a watering with fish emulsion. Odds are, though, that your soil has plenty of nitrogen for tomato plants, and breakdown of compost over the season will resupply what the tomato plants use up. (If you do use some fish, you might put out a raccoon trap with some cat food in it at the same time. Fish attracts raccoons.) __________________ -- alias

April 28, 2008	#3
cecilsgarden1958 Tomatovillian™ Join Date: May 2006 Location: swPA Posts: 629	Alias: Thanks for the reply. Lots of good insight there. I appreciate it. Sounds like everything is okay to plant, then. I was worried that the nitrate level was to high and would burn. Again, I appreiciate the reply. Thanks. CECIL __________________ Hybrids Rule, Heirlooms Drool!