TITLE:
Agricultural Phosphorus Management for Environmental Protection: A Review
AUTHORS:
Tesha Mardamootoo, Christiaan Cornelius Du Preez, Johannes Hendrikus Barnard
KEYWORDS:
Mitigation Strategies, Non-Point Source Pollution, Phosphorus Indices, Phosphorus Models, Water Pollution
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.9 No.8,
August
12,
2021
ABSTRACT: This review addresses research done over the past
40 years on different aspects of agricultural phosphorus (P) management for
environmental protection. Inputs of P are essential for profitable crop
production. Long-term application of P to agricultural soils has resulted in
elevated levels of soil P. This accumulation may be desirable from an agronomic
point of view but it represents a threat to freshwater quality. Indeed, P in
runoff from agricultural land is an important component of non-point source
pollution and can accelerate eutrophication of lakes and streams. Even very
small amounts of P can raise the concentration above the critical value for
eutrophication. Excessive eutrophication restricts water use for recreation,
industry, and drinking due to the increased growth of undesirable algae and
aquatic weeds. Current concerns facing the environmentally sound management of
P in agriculture are similar worldwide and revolve around agricultural,
economic, and environmental compromises associated with balancing productivity
with environmental values. Agricultural P management strategies should be
geared towards ensuring that P, a finite earth resource, is not wasted and those
soils do not become so enriched with P that there is an unnecessary risk of too
much P being mobilized to water from agricultural fields. Approaches, such as
soil P testing and either P models or indices have been studied and implemented
to mitigate agricultural P losses. Apparently, P indices are preferred instead
of P models for this purpose because they are more flexible. A holistic
management strategy is therefore suggested by using soil P testing in
conjunction with either a P index or a P model.