Management › Fertilization › Type of fertilizer › Inorganic fertilizer → Properties

Urea fertilizer → pH

Consistent result

83 %

of 18 studies with a clear result report a significant decrease

-4 %

typical change (12 studies with numbers)

studies · 20 findings

Count each study by

19 studies · 20 findings

What the studies show

15 of 18 studies report a significant decrease (83 %, 95 % confidence interval 61–94 %).

By the direction of each study’s results, significant or not: 1 of 17 studies with a direction point up (6 %, 95 % confidence interval 1–27 %; sign test p < 0.001).

↑ 1 increase
↓ 15 decrease
= 2 no effect
? 1 unclear

How large: typically -4 % (middle half -8 % to -3 %), from 12 studies with numbers
Basis: 19 studies, 20 findings; 0 entered by hand, 19 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 0 % of the studies under urea fertilizer, stays the same in 14 % and goes down in 86 %.

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…