How many g of fertilizer per kg of soil?

freedom21February 22, 2011

I am not sure that is the right place to post but you may help me

I need to calculate how much of Se there is per kg of soil in the 0-30 cm soil layer (bulk density 1.3 g per cm3)if I will apply 10 g of Se per ha.

They told me that the answer is 2.6 um per kg, but I can't find how they calculate it


Thank you for reporting this comment. Undo
bluegoat_gw(Zone 3b)

The trick is to know that an acre furrow weighs about 2,000,000 lbs. That is one acre by the depth of a moldboard plough - 6.67" and with soil bulk density of 1.3 gms/cc weighs 2,000,000 lbs.

This gives you a convenient conversion to ppm. For example, adding 2 lbs. per acre of a nutrient is adding 1 ppm. Since soil analysis gives values in ppm or ppm equivalent, it is easy to determine fertilizer application on a per acre basis.

You will need to do some metric conversion but this should be the way to go about it.

A depth of 30 cm. is deeper than 6.67"; it's nearly a foot. There may be a metric version that is a hectare by 30 cm deep. How much does that weigh? Bulk density is 1,300 kg/m^3 metrically.

1 hectare = 10,000 m^2 * 0.3 m = 3,000 m^3

3,000 m^3 * 1,300 kg/m^3 = 3,900,000 kg

How useful is that?

Anyway, that's my contribution. Good night.

    Bookmark   February 23, 2011 at 1:24AM
Thank you for reporting this comment. Undo
bluegoat_gw(Zone 3b)

Since no one has finish off this question, I will try with a bit of Grade 7 math.

10 grams = 0.01 kgs.

0.01 kgs. / 3,900,000 kgs. = 2.564^-9 kgs. per hectare

That's seems closer to nanograms than micrograms.

In other words, compost made from diverse materials should provide this level of Se. I have no idea of how else one would add that small a quantity with accuracy.

    Bookmark   February 24, 2011 at 6:35PM
Thank you for reporting this comment. Undo
DrHorticulture_(Z3 Central Saskatchewan)

Bluegoat's answer is correct i.e. 2.564 micrograms per kg (but not nanograms. 10^-9 kg is 1 microgram).

    Bookmark   February 24, 2011 at 8:38PM
Thank you for reporting this comment. Undo
bluegoat_gw(Zone 3b)

I know that I should not argue with a Saskatchewan farmer but then there is a chance that you are not a farmer. But since you are correct, you probably are a farmer.

Nano-kgs. become micrograms. That's what I missed. Thank you.

    Bookmark   February 24, 2011 at 10:08PM
Thank you for reporting this comment. Undo

For the rest of us who talk english might the writer tell us why the use of b.s. malarkey, h.s., and an attempt to prove she got through kindergarten does for the gardener who thinks in pounds, inches, acres and yes, even hectares...
Dealing with fertilizer in specific terms involving grams is hardly something that will catch the eye of the reader.
Since a gram is just about the smallest measure to deal with in most instances of gardening, it would be better for the writer to catch up to the 20th century.

    Bookmark   February 25, 2011 at 7:00PM
Thank you for reporting this comment. Undo
DrHorticulture_(Z3 Central Saskatchewan)


Not sure who you're referring to but I suggest that you may have some adapting to do yourself. I mean, who the heck uses pounds and inches, besides for a few Americans? I sure don't and I never have, all my life. I measure everything in grams, metres and litres, thank you very much. Metric is what scientists use, and metric is the only globally accepted system of measurement. As for your last sentence, look up what kilograms are.

Trust me, life is much simpler in metric.

    Bookmark   February 25, 2011 at 7:27PM
Thank you for reporting this comment. Undo

I was going to ask if I could buy a vowel!!



    Bookmark   February 25, 2011 at 7:41PM
Thank you for reporting this comment. Undo

Could please kindly tell me, what is the role for the approximately number of Kg of soil per hectare? And do you have reference for this that I can use it? because I would like to caculate how many kg Cadmium (Cd) cand be found in one hectare. I know howm any g of Cd is found in Kg soil.�

please send me email on

    Bookmark   March 8, 2011 at 3:42AM
Sign Up to comment
More Discussions
Need Help With French Drain
Hi All, I just purchased my first house. After all...
Miracle Compost Additive!
Added a bunch to my compost pile and it heated right...
Hand crank or battery grinder/ chipper for the garden?
Good morning all. I'm new to these forums and have...
what say you on on reusing ashes to soil?
We barbecue often and use charcoal (absolutely no lighter...
flyinbtsomypants (WestCent.FL Z9b-10a)
First time gardener. need help with pest
This is the first time I will be planting a vegetable...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™