Management › Fertilization › Type of fertilizer → Properties › Biology › Microorganisms/Microbes

Manure → Microbial biomass Carbon

Consistent result

79 %

of 24 studies with a clear result report a significant increase

+36 %

typical change (16 studies with numbers)

studies · 32 findings

Count each study by

26 studies · 32 findings

What the studies show

19 of 24 studies report a significant increase (79 %, 95 % confidence interval 60–91 %).

By the direction of each study’s results, significant or not: 22 of 23 studies with a direction point up (96 %, 95 % confidence interval 79–99 %; sign test p < 0.001).

↑ 19 increase
↓ 1 decrease
⇅ 1 both
= 3 no effect
? 2 unclear

How large: typically +36 % (middle half +15 % to +58 %), from 16 studies with numbers
Basis: 26 studies, 32 findings; 0 entered by hand, 26 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 75 % of the studies under manure, stays the same in 13 % and goes down in 0 %.

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…