Management › Tillage → Properties

Conventional tillage → pH

The studies disagree

52 %

of 85 studies with a clear result report a significant increase

+2 %

typical change (57 studies with numbers)

studies · 126 findings

Count each study by

86 studies · 126 findings

What the studies show

44 of 85 studies report a significant increase (52 %, 95 % confidence interval 41–62 %).

By the direction of each study’s results, significant or not: 50 of 75 studies with a direction point up (67 %, 95 % confidence interval 55–76 %; sign test p = 0.005).

↑ 44 increase
↓ 24 decrease
⇅ 5 both
= 12 no effect
? 1 unclear

How large: typically +2 % (middle half -2 % to +6 %), from 57 studies with numbers
Basis: 86 studies, 126 findings; 12 entered by hand, 74 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 56 % of the studies under conventional tillage, stays the same in 10 % and goes down in 27 %.

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…