Management › Fertilization → Properties › Biology › Microorganisms/Microbes

Organic fertilizer → Microbial biomass Carbon

Consistent result

85 %

of 47 studies with a clear result report a significant increase

+49 %

typical change (29 studies with numbers)

studies · 59 findings

Count each study by

50 studies · 59 findings

What the studies show

40 of 47 studies report a significant increase (85 %, 95 % confidence interval 72–93 %).

By the direction of each study’s results, significant or not: 45 of 46 studies with a direction point up (98 %, 95 % confidence interval 89–100 %; sign test p < 0.001).

↑ 40 increase
↓ 1 decrease
⇅ 1 both
= 5 no effect
? 3 unclear

How large: typically +49 % (middle half +23 % to +74 %), from 29 studies with numbers
Basis: 50 studies, 59 findings; 0 entered by hand, 50 read by the library

Every study counts once, however many findings it reports: one with 40 sampling dates does not outvote ten others. A study with a significant increase and decrease (say at different depths) counts as "both". A first synthesis for orientation, not a substitute for a systematic review.

Where the studies are

goes up
stays the same
goes down
both ways

Through the soil profile

Each layer on its own: a study that reports the topsoil and the subsoil counts in both. Choose a layer to see what goes with it.

goes up
stays the same
goes down
both ways

In the top 10 cm, microbial biomass Carbon goes up in 80 % of the studies under organic fertilizer, stays the same in 7 % and goes down in 7 %.

What makes a difference

The conditions whose levels differ most clearly, each with the outcome that differs most between its levels of at least 10 study layers. Choose a layer in the profile to see them for that layer alone, or a level here to filter by it.

Testing every condition on every study layer…

Along the conditions

Testing every condition on every study layer…