Management › Fertilization › Type of fertilizer → Properties › Chemistry

Manure → Available phosphorus

Consistent result

86 %

of 29 studies with a clear result report a significant increase

+150 %

typical change (18 studies with numbers)

studies · 36 findings

Count each study by

29 studies · 36 findings

What the studies show

25 of 29 studies report a significant increase (86 %, 95 % confidence interval 69–95 %).

By the direction of each study’s results, significant or not: 25 of 27 studies with a direction point up (93 %, 95 % confidence interval 77–98 %; sign test p < 0.001).

↑ 25 increase
↓ 2 decrease
⇅ 1 both
= 1 no effect

How large: typically +150 % (middle half +49 % to +318 %), from 18 studies with numbers
Basis: 29 studies, 36 findings; 1 entered by hand, 28 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, available phosphorus goes up in 100 % of the studies under manure, stays the same in 0 % 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…