Agriculture Reference
In-Depth Information
10.6 lb of Sodium Na+
Per Hectare
, to a depth of 15cm to 17cm, 1 meq or ME=
20 kg of Hydrogen H+
400 kg of Calcium Ca++
240 kg of Magnesium Mg++
780 kg of Potassium K+
460 kg of Sodium Na+
To convert hectares to 100 m
2
move the decimal point 2 places to the left: 400
kg/ha = 4.0 kg/ 100m
2
Metric Measurements: Kilograms and Hectares:
The convention used for estimating lbs/Acre in the English/Avoirdupois system is
that the top 6” to 7" (15 to 18 cm) of an acre of soil weighs 2 000 000 (two million)
pounds, so one part per million (1 ppm) = 2 lbs/acre.
The convention used for estimating kilograms per hectare (kg/ha) is that the top
15 to 18 cm (6” to 7") of a hectare of soil weighs 2 000 000 kg, so 1 ppm = 2 kg/ha.
Considering the huge variance in soil densities, from light weight peat-type soils to
heavy clays, unless one wishes to dig up, dry, measure, and weigh a volume
sample of the particular soil they are working with, it's safe enough for agricultural
purposes to simply say:
1ppm = 2 lb/acre = 2 kg/hectare
1ppm = 20g/1000ft
2
= 20g/100m
2
When calculating soil amendments, be conservative. If you think the amount you
are putting on may be too much, use less. It's a lot easier to add more than it is
to take something out after adding too much.
To calculate CEC accurately, see the appendix section “Calculating
TCEC”.
