Requirements
- Phosphoric acid
- pH and E.C meter
- Pumice
- Hand gloves
- 40L of clean plain water
- 60L containers
Procedure
- Double rinse the pumice using clean plain water
- Take E.C and Ph readings
- Add 5ml phosphoric acid to 40L of clean water and stir using a rod
- Pour pumice into the phosphoric acid solution and stir thoroughly
- Take Ph, E.C and temperature readings
- Rinse pumice with clean water and mix proportionally with treated cocopeat
CROP | ELECTRONIC CONDUCTIVITY |
Lettuce-loose headed | 0.3-0.8 |
Lettuce-compact headed | 0.6-1.4 |
Tomato | 1.8-2.8 |
Peppers | 1.8-2.8 |
Spinach/collards | 1.8-3.5 |
Straw berries | 1.8-2.5 |
Asparagus | 1.4-1.8 |
cabbage | 1.4-2.4 |
Egg plant | 1.8-2.2 |
Cauliflower | 1.4-2.4 |
Maize | 1.6-2.4 |
parsley | 0.8-1.8 |
okra | 2.0-2.4 |
pumpkin | 1.4-2.4 |
cucumber | 1.6-2.4 |
peas | 1.4-1.8 |
beans | 1.8-2.5 |
NB:Phosphoric acid is highly corrosive, should be handled with a lot of care. Wear gloves when treating pumice, when stirring use a rod.
The above E.C table shows just few crops grown in Kenya, to get the other crops E.C values it’s just a matter of knowing the crop family. All crops within one family differ slightly in the E.C values basically due to differences in nutritional demands.