Abstract:
Analyses of loamless composts is carried out on three extracts at a 1:2 volume to volume, sample - extractant ratio
- distilled water
- saturated calcium sulphate
- m - ammonium acetate
pH and conductivity are determined on the water extract, nitrogen, phosphate and potash are determined on the filtered calcium sulphate extract and calcium and magnesium on the filtered ammonium acetate extract.
The recommended levels of nutrients for tomatoes grown in a peat substrate are:
| nitrogen |
500–100 ppm |
|
| phosphate |
30–50 ppm |
(13–22 ppm P)
|
| potash |
350–450 ppm |
(290–374 ppm K)
|
| calcium |
1000 ppm |
|
| magnesium |
200 ppm |
|
| calcium/magnesium ratio |
5:1 |
|
| ph |
5.5–6.0 |
|
| pC |
3.0–2.9 |
(conductivity 1000–1300 micro-mhos,10–13CF)
|
|