SOIL
SAMPLING IN NO-TILL
Research indicates that
phosphorous (P) and potassium (K) layers or concentrates near the soil surface
in no-tillage and reduced tillage systems. Because of this stratification of
nutrients, split sampling can be used to see if corrective action is necessary.
The routine method of sampling
no-tillage fields is as follows:
a) 0-2 inch sample to check
for soil pH and lime requirement. When nitrogen fertilizers such as urea or
(UAN) solutions are applied to the surface in no-till systems, the surface few
inches can become acid very quickly. This can affect both herbicide activity
and plant growth.
b) 0-8 inch sample to check
for all nutrient requirements.
Sample can be split into a top 4" section and a bottom 4" section if so desired.
P AND K
SOIL TEST LEVELS FOUND AT VARIOUS DEPTHS IN THE SOIL (CRUZ, 1982)
| Depth |
Plow |
Chisel |
No-till |
Plow |
Chisel |
No-till |
| inches |
Bray P1 (ppm) |
Exch. K (ppm) |
| 0-3 |
37 |
85 |
90 |
150 |
230 |
285 |
| 3-6 |
47 |
35 |
27 |
165 |
105 |
100 |
| 6-9 |
30 |
15 |
18 |
140 |
100 |
100 |
| 9-12 |
8 |
8 |
8 |
100 |
100 |
100 |
Corn,
Soybean, Wheat, and Alfalfa Field GuideBulletin 827|