Add peat to soil (alongside planting/seeding)

How is the evidence assessed?
  • Effectiveness
    42%
  • Certainty
    20%
  • Harms
    0%

Study locations

Key messages

  • One replicated, randomized, controlled study in the UK found that adding peat to soil and sowing seed increased the cover of common heather in the majority of cases, compared to seeding alone. One replicated, randomized, controlled study in the UK found that adding peat to soil and sowing seed increased the density of heather seedlings, and led to larger heather plants than seeding alone, but that no seedlings survived after two years.

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 replicated, randomized, controlled study in 1991–1993 in former agricultural fields in Norfolk, UK (Davy et al. 1998) found that addition of peat to agricultural soils alongside sowing of seed increased the density of heather Calluna vulgaris seedlings in seven of eight trials, and led to larger heather plants, but no heather seedlings survived after two years. After one year, in seven of eight trials, the density of heather seedlings was higher in areas where peat had been added to agricultural soils and heather seed sown (30–66 seedlings/plot) than in areas where heather seed was sown but no peat had been added (5–16 seedlings/plot). However, after two years no seedlings survived in any plots. After one year heather plants were larger in six of eight trials in areas where peat had been added to soils along with seed (5–58 whorls/plant) than in areas where seed had been sown but no peat had been added to soils (1–15 whorls/plant). Thirty-six water tanks were inserted into the ground in September 1991, twenty-four of which contained a mixture of peat and agricultural soil and 12 of which contained only agricultural soil. All tanks were sown with heather shoots that had been harvested in autumn. 10 cm x 10 cm quadrats were placed in each tank and used to monitor the abundance of heather seedlings between June and September 1992.

    Study and other actions tested
  2. A replicated, randomized, controlled study in 1992–1997 in an agricultural field that was previously heathland in Suffolk, UK (Dunsford et al. 1998) found that in two of three cases adding peat to soil, followed by sowing of seed of shrubland plants increased cover of common heather Calluna vulgaris compared to seeding alone. In two of three cases common heather cover was higher in areas where peat was added to soil and seed sown (40–49%) than areas where only seed was sown (8%). In 1992 peat was added to 18 randomly located 4 m x 8 m plots and seeds were sown, while only seeds were sown in 6 other plots. Thirty-two 1 m2 quadrats placed in each plot which were used to record the cover of common heather in August 1994 and September 1997.

    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

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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

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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.

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