Management › Tillage › Tillage system → Properties

Reduced tillage → pH

The studies disagree

46 %

of 28 studies with a clear result report a significant decrease

-0 %

typical change (19 studies with numbers)

studies · 41 findings

Count each study by

30 studies · 41 findings

What the studies show

13 of 28 studies report a significant decrease (46 %, 95 % confidence interval 30–64 %).

By the direction of each study’s results, significant or not: 12 of 26 studies with a direction point up (46 %, 95 % confidence interval 29–65 %; sign test p = 0.845).

↑ 9 increase
↓ 13 decrease
⇅ 2 both
= 4 no effect
? 2 unclear

How large: typically -0 % (middle half -2 % to +3 %), from 19 studies with numbers
Basis: 30 studies, 41 findings; 5 entered by hand, 25 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 11 % of the studies under reduced tillage, stays the same in 22 % and goes down in 67 %.

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…