|
| |
Values for soil analyses that may be used as a guide in interpretation of soil test results
| Soil analysis |
optimal |
low |
med |
high |
excessive |
Notes: |
| pH |
6.0-7.5 |
<5.0 |
|
>7.5 |
|
|
| soluble salts |
<1.0 |
|
|
>3.0mmho/cm |
>4.0mmho/cm |
|
| sodium (ESP) |
<15% |
|
|
>15% |
|
|
potastium
(ppm)* |
120-200 |
< 150 |
150-250 |
250-800 |
>800 |
Ammonium acetate method used** |
calcium
(ppm)* |
600-4000 |
<1000 |
1000-2000 |
>2000 |
|
|
magnesium
(ppm)* |
60-480 |
<60 |
60-180 |
>180 |
|
|
phosphorus
(ppm) |
10-20 |
<10 |
10-20 |
20-40 |
>40 |
Olsen test used E. of Cascades |
boron
(ppm) |
0.5-2.0 |
<0.5 |
0.5-2.0 |
>2.0 |
|
|
sulfate-S
(ppm) |
6-20 |
<2 |
2.0-10.0 |
>10 (sufficient) |
|
|
nitrate
(ppm)*** |
5-15 |
<5 |
|
>100 |
|
|
| zinc (ppm) |
>1.0 |
|
|
|
|
using DTPA extraction method |
| copper (ppm) |
>0.6 |
|
|
|
|
using DTPA extraction method |
| manganese (ppm) |
>1.5 |
def. only on soils pH > 7.0 |
toxicities may occur on acid soils |
using DTPA extraction method |
| iron |
N/A |
|
|
|
|
|
| molybdenum |
N/A |
|
|
|
|
|
| Chloride |
N/A |
|
|
|
|
|
*Want the following relationship: Ca>Mg>K. Ca:Mg ratio may range from 1:1 to 20:1
**lower values expected for sodium bicarbonate method
***ppm nitrate = 10(ppm nitrate-N)
On the average, the C/N/P/S ratio in soil is 140/10/1.3/1.3
|
Mobile soil nutrients
(i.e., easily leached) |
Non-mobile soil nutrients
(strongly sorbed by soil components) |
| NO3-, B, SO42- and Cl |
P, K, NH4+, Ca, Mg, Zn, Cu, Fe, and Mn |
Updated
July 9, 2004
|
|
