Management › Fertilization › Type of fertilizer → Properties

Manure → pH

A clear tendency, not consistent

63 %

of 30 studies with a clear result report a significant increase

+6 %

typical change (22 studies with numbers)

studies · 35 findings

Count each study by

32 studies · 35 findings

What the studies show

19 of 30 studies report a significant increase (63 %, 95 % confidence interval 46–78 %).

By the direction of each study’s results, significant or not: 20 of 28 studies with a direction point up (71 %, 95 % confidence interval 53–85 %; sign test p = 0.036).

↑ 19 increase
↓ 7 decrease
= 4 no effect
? 2 unclear

How large: typically +6 % (middle half -1 % to +11 %), from 22 studies with numbers
Basis: 32 studies, 35 findings; 1 entered by hand, 31 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, pH goes up in 73 % of the studies under manure, stays the same in 9 % and goes down in 18 %.

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…