Add gypsum to soil (alongside planting/seeding)

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

Study locations

Key messages

  • One randomized, controlled study in South Africa found that adding gypsum to soils and sowing seeds increased survival of seedlings for one of two species

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A randomised, controlled study in 1994–1998 in a succulent karoo shrubland in Western Cape, South Africa (Beukes & Cowling 2003) found that applying gypsum, followed by sowing the seeds of shrubland species increased the number of seedlings of these species, and increased seedling survival of one of two species. Applying gypsum followed by sowing the seeds of the species Karoo bietou Tripteris sinuata, Spiny ruschia Ruschia spinosa and Gha grass Chaetobromus dregeanus increased the number of seedlings of these species compared plots where unmulched, unseeded plots (data not provided). Applying gypsum followed by seeding increased the survival of seedlings of Karoo bietou relative to areas that where gypsum had not been applied and that were not seeded (data not provided), but there was no difference in the survival of Gha grass. In 1994 eight 12.5 m2 plots were established. In four plots gypsum (CaSO4) was applied at a rate of 5 tonnes/ha, followed by sowing of the seeds of shrubland species. In the other four plots no mulch was applied, and no seeds were sown. Seedlings in each plots were counted annually between 1994 and 1998.

    Study and other actions tested
Please cite as:

Martin, P.A., Rocha, R., Smith, R.K. & Sutherland, W.J. (2020) Shrubland and Heathland Conservation. Pages 483-525 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Shrubland and Heathland Conservation

This Action forms part of the Action Synopsis:

Shrubland and Heathland Conservation
Shrubland and Heathland Conservation

Shrubland and Heathland Conservation - Published 2017

Shrubland and Heathland synopsis

What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 20

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered speciesVincet Wildlife Trust