Management › Fertilization → Properties › Biology

Inorganic fertilizer → Yield

A clear tendency, not consistent

60 %

of 121 studies with a clear result report a significant increase

+23 %

typical change (87 studies with numbers)

129

studies · 209 findings

Count each study by

129 studies · 209 findings

What the studies show

72 of 121 studies report a significant increase (60 %, 95 % confidence interval 51–68 %).

By the direction of each study’s results, significant or not: 84 of 105 studies with a direction point up (80 %, 95 % confidence interval 71–87 %; sign test p < 0.001).

↑ 72 increase
↓ 18 decrease
⇅ 8 both
= 23 no effect
? 8 unclear

How large: typically +23 % (middle half +2 % to +68 %), from 87 studies with numbers
Basis: 129 studies, 209 findings; 1 entered by hand, 128 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 layers of unstated depth, yield goes up in 60 % of the studies under inorganic fertilizer, stays the same in 18 % and goes down in 15 %.

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…