TITLE:
Integrating Source and Transport Factors with Best Management Practices to Derive an Index for Assessing Phosphorus Mobilization Risks from Mauritius Sugarcane Fields
AUTHORS:
Tesha Mardamootoo, Christiaan Cornelius du Preez
KEYWORDS:
Dissolved Phosphorus, Particulate Phosphorus, Phosphorus Fertiliser, Soil Erosion, Surface Runoff
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.10 No.4,
April
24,
2022
ABSTRACT: Application of phosphorus (P) fertilisers to sugarcane fields in
Mauritius increased almost four-fold per unit area over the past 60 years. Some
of the applied P accumulated in the soils and can therefore be transported eventually to surface waters resulting in the eutrophication
thereof. Precaution measures such as an appropriate P index as a management
tool is required. Source factors (dissolved
P, particulate P, P application rates, methods and timing), transport factors (soil erosion, runoff
potential and precipitation factor) and a best management practices multiplier
were integrated to derive an index for assessing risks of P mobilisation from the
island’s sugarcane fields. Farmers and their advisors can use the proposed P
index during the planning process before sugarcane fields are planted and
will be applicable for the whole crop cycle of 6 - 7 years
if factors in the index do not change. The index can be also valuable in the
selection of alternative management practices that could reduce the risks of P losses from sugarcane fields
where the potential of P movement is initially high. Sensitivity
analyses and edge-to-plot field tests showed that the P index needs further improvement, especially the estimation of soil erosion rates. The P
index can, however, be applied by farmers and their advisors if they are well
informed about the index’s capability.