Soil Tests

Here are the results for a week long incubation test on some char/peat moss mixes.

Char is portioned by volume. The density of the char and the peat moss are very close but I don’t have the #s. I can do so but must oven dry the two  and did not take the time yet.

EC units are micro-siemens/cm.

Tests are done using a SME or saturated media extract.

Please note that second table with EC values has been modified due to an error in the setting of the EC meter.

pH measurements
0 1 4 7 29
Berger BM8 5.8 5.8 5.7 5.7 6.1
Peat Moss 4.3 4 3.8 4 3.9
Peat Moss 5% char 4.4 4.2 4.2 4.3 4.2
Peat Moss 10% char 4.5 4.4 4.3 4.5 4.4
Peat Moss 25% char 5.3 5.2 5.2 5.3 5.1
EC measurments
Berger BM8 1260 1370 1330 1320 1380
Peat Moss 240 300 396 328 260
Peat Moss 5% char 510 450 480 362 400
Peat Moss 10% char 540 480 560 480 460
Peat Moss 25% char 960 840 1080 760 670

Petunia Seedlings with Biochar

We did a simple test of mixing 10% biochar with our normal seedling mix and then seeing how Petunias would do.

Here is a picture of the Petunias in our normal seedling mix.;



…and here is a picture of the same variety with the 10% char mix;




It doesn’t come across in the photos as well as it might but you can see some intervienal chlorosis which is likely indicative of iron deficiency.

I tested the EC and it was 1250 for both of the trays. The ph was 6.2 for the normal mix and 7.1 for the char mix. The char has raised the pH enough to cause the iron deficiency. We realy like to grow petunias closer to a pH of 5.5 and  should be treating these flats with acid to lower the pH. As it stands both trays have recieved the same treatment.