Management › Tillage → Properties › Biology › Diversity

Conservation tillage → Species richness

A clear tendency, not consistent

54 %

of 24 studies with a clear result report a significant increase

+14 %

typical change (12 studies with numbers)

studies · 52 findings

Count each study by

28 studies · 52 findings

What the studies show

13 of 24 studies report a significant increase (54 %, 95 % confidence interval 35–72 %).

By the direction of each study’s results, significant or not: 18 of 21 studies with a direction point up (86 %, 95 % confidence interval 65–95 %; sign test p = 0.001).

↑ 13 increase
↓ 3 decrease
⇅ 3 both
= 5 no effect
? 4 unclear

How large: typically +14 % (middle half +2 % to +34 %), from 12 studies with numbers
Basis: 28 studies, 52 findings; 2 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, species richness goes up in 50 % of the studies under conservation tillage, stays the same in 33 % 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…