Importance

The length of time that water remains ponded on the surface indicates the rate of infiltration into the soil, and the time that the soil remains saturated. Prolonged water logging depletes oxygen and causes carbon dioxide to build up.

Anaerobic conditions develop and induce a series of chemical and biochemical reduction reactions that produce products that are toxic to plant roots. Organic substances can also anaerobically degrade in these soils and the soil goes ‘sour’. Water logging delays cultivation because the low load-bearing capacities of the soil increase its susceptibility to damage through deformation and excessive wheel slip.

Assessment

Assess the degree of surface ponding. Base the assessment on the time the water took to disappear following a wet period, or after heavy rainfall in the winter.

Good
Moderate
Poor

Scoring

Good condition: Score 2

No evidence of surface ponding after 1 day following heavy rainfall on soils that were already at or near saturation.

Moderate condition: Score 1

Moderate surface ponding can occur up to 3 days after heavy rainfall on soils that were already at or close to saturation.

Poor condition: Score 0

Significant surface ponding can occur for longer than 3 days after heavy rainfall on soils that were already at or close to saturation.

References

http://adlib.everysite.co.uk/adlib/defra/content.aspx?id=000HK277ZX.0HDECKKQLJIF9JD

ftp://ftp.fao.org/docrep/fao/010/i0007e/i0007e01.pdf