The decline of soil organic matter
content of South Africa’s nonrenewable soil resource base poses a
serious threat to sustainable food production through agriculture. The organic matter content of soils is an
indicator of soil health1 and soil quality2. Measurement of soil respiration
provides an indication of soil quality
and soil fertility.
Applicable methods are evaluated
to measure carbon dioxide (CO2)
production and extractable C, extractable organic N, extractable inorganic N, P, K and extractable Al, Fe
and P to complete a soil health data
set for use in the calculation of a soil
health assessment. This health assessment can be applied to any soil or
plant medium substrate such as discard, tailings and other materials.
Applications of soil health assessments include:
Fertiliser application rate assessments to avoid over fertilisation .
Assessing degraded soil and land
capability such as:
Ploughed land compared to
no-till and variations thereof;
Overgrazed land;
Opencast mined rehabilitated
land;
Vegetated covers; and
Contaminated land.
Definitions (Soil Science Society of
America).
Definition1. “Soil health is defined as
the capacity of a soil to function
within ecosystem boundaries to sustain biological productivity, maintain
environmental health, and promote
plant and animal health.”
Definition2. “Soil quality is the capacity within natural or managed ecosystem boundaries, to sustain plant and
animal productivity, maintain or enhance water and air quality, and
support human health and habitation.”
Hendrik Smith is now associated with
NviroTek Laboratories on a part time
basis. Hendrik Smith is a registered
Professional Natural Scientist (Soil
Science) with the South African
Council for Natural Scientific Professions. He has a long history of working on projects related to water
quality (irrigation water and effluents), soil quality and soil surveys.
Hendrik in association with Adam
Loock, previously from the Agricultural Research Council (ARC) Institute
for Soil climate and Water, are involved with NviroTek Laboratories to
diversify the present analytical expertise into environmentally related
substrate, soil, water and vegetation
analyses. Supporting data evaluation and interpretation services will
be provided in line with client needs.
In addition, the neglected soil biology concept supporting the quantification of soil health will be evaluated commercially.