Management › Crops → Properties › Physics

Crop rotation → Bulk density

A clear tendency, not consistent

60 %

of 10 studies with a clear result report a significant decrease

-5 %

typical change (6 studies with numbers)

studies · 15 findings

Count each study by

10 studies · 15 findings

What the studies show

6 of 10 studies report a significant decrease (60 %, 95 % confidence interval 31–83 %).

By the direction of each study’s results, significant or not: 1 of 8 studies with a direction point up (13 %, 95 % confidence interval 2–47 %; sign test p = 0.07).

↑ 1 increase
↓ 6 decrease
⇅ 2 both
= 1 no effect

How large: typically -5 % (middle half -6 % to -2 %), from 6 studies with numbers
Basis: 10 studies, 15 findings; 1 entered by hand, 9 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, bulk density goes up in 17 % of the studies under crop rotation, stays the same in 17 % and goes down in 50 %.

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…