Hello,
Greetings to experts and friends,
Total Kjeldahl Nitrogen is standard test used to determine soil nitrogen.
Once we have the values of the test in %, how do we convert it to kg per ha?
It is a typical vertisol, so we can make typical bulk density and soil depth assumptions for short duration grain crops.
Looking forward to your help.
Thanking you,
check this link maybe help you
https://books.google.com.mx/books?id=WdUbdiNNYwMC&pg=PA60&lpg=PA60&dq=How+is+TKN+convert+kg/ha&source=bl&ots=gtn9sd_Kct&sig=ACfU3U2Yw-LaDyaz5ajulZ9woWhscLyD6A&hl=es&sa=X&ved=2ahUKEwiAoJLF8rXoAhUOheAKHdolAgUQ6AEwCnoECAYQAQ#v=onepage&q=How%20is%20TKN%20convert%20kg%2Fha&f=false
The sum requires the concentration of N in g/kg and the crop yield in kg/ha. The product is g N/ha
@ Rohan, amount of soil (15 cm plow layer) in one ha is 22,42,000 Kg
% means kg/100kg
Therefore you have to multiply by 22,42,000/100 = 22,420 to convert your value into kg/ha
Hi Rohan, this is a simple calculation if you have the measured bulk density for your soil depth. For instance, let's say that you sampled a 10 cm depth layer and found a bulk density of 1.3 g /cm3 and 1.5% of total N. Then:
1.5% N * 10 * 1.3 g/cm3 = 19.5 ton N/ha.
We multiply % (g/100g) to get g N/kg and the result is in ton/ha. To get kg/ha just multiply by 1000 (since 1 ton is 1000 kg).
Giovani Preza-Fontes, thanks for your above answers; I really appreciate that. I have another question,
Let's say we want to calculate soil total carbon (STC), I got lab results as %, for example, 0.9555 %
Bulk density: 1.7333 g/cm3
Depth of sampling: 30 cm
my calculation: 0.9555* 1.7333*30*1000(to convert the result into kg/ha)
in the end, I got: 49688.75 kg/ha STC, which is unusual to me.
Would you please help me?
Thank you.
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