Sugarcane Production Impact on Nitrogen and Phosphorus in Drainage Water from an Everglades Histosol
- F. J. Coale *,
- F. T. Izuno and
- A. B. Bottcher
The Everglades Agricultural Area (EAA) in southern Florida is a 280 000-ha tract of land that has come under scrutiny by environmental, agricultural industry, and government water management groups that are concerned with the impact of nutrient-enriched drainage water on the ecology of adjoining bodies of water and wetlands. Sugarcane (Saccharum sp.) is grown on 155 000 ha or 78% of the cultivated organic soils in the EAA. The objectives of this study were to determine the N and P concentrations and off-field loads in drainage water from sugarcane and fallow fields. Sugarcane was planted in four of eight hydraulically independent and similar field plots. Four plots were maintained fallow. Drainage water volume, and total nitrogen (TN), total dissolved phosphorus (TDP), and total phosphorus (TP) concentrations were monitored during 12 drainage events during two crop seasons. For two drainage events, TN concentrations were higher in drainage water from fallow plots that in drainage water from sugarcane plots and it was speculated that crop uptake of mineralized soil N may have contributed to the reductions during these events. Analysis of the mean for the 12 drainage events indicated no overall differences in TN off-field loads between sugarcane and fallow plots. Further, no significant differences were found in TDP or TP concentration in drainage water from sugarcane and fallow plots during any of the drainage events monitored. It was concluded that, due to the large quantity of soil N and P mineralized and due to crop N and P uptake, the impact of sugarcane production on drainage water N and P concentrations was minimal.
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