Management › Fertilization → Properties › Biology › Plants

Inorganic fertilizer → Aboveground biomass

A clear tendency, not consistent

63 %

of 27 studies with a clear result report a significant increase

+83 %

typical change (15 studies with numbers)

studies · 46 findings

Count each study by

29 studies · 46 findings

What the studies show

17 of 27 studies report a significant increase (63 %, 95 % confidence interval 44–78 %).

By the direction of each study’s results, significant or not: 21 of 25 studies with a direction point up (84 %, 95 % confidence interval 65–94 %; sign test p < 0.001).

↑ 17 increase
↓ 4 decrease
⇅ 4 both
= 2 no effect
? 2 unclear

How large: typically +83 % (middle half +13 % to +113 %), from 15 studies with numbers
Basis: 29 studies, 46 findings; 0 entered by hand, 29 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, aboveground biomass goes up in 65 % of the studies under inorganic fertilizer, stays the same in 8 % 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…