Abstract
One of the most pressing problems in the environment today is the issue of excessive nutrient loading into aquatic systems. The ramifications of eutrophication can be seen through harmful algal blooms (HABs), decreased water quality, dead zones for aquatic life, and deleterious human health effects. One of the leading causes of nutrient surpluses in lakes, streams, rivers, and estuaries is often urban and agricultural runoff. Wetlaculture, an ecological engineering approach, is the rotation of landscapes back and forth between wetland and agricultural systems. This involves the creation and use of treatment wetland ecosystem services for the removal of excess nutrients, coupled with agriculture to utilize those retained nutrients. This study investigated how wetlaculture worked in experimental mesocosms in subtropical Naples, Florida with varied hydraulic loading rates and water depths. The analysis included determining wetland nutrient removal efficiencies and nutrient concentrations in wetland soil and vegetation in the first phase, and the production of sweet corn in phase two of the study. High loading, deep water wetlands provided the highest nutrient removal in the calendar year 2021, with 97.8% removal of nitrate+nitrite (NO3-+NO2-), 63.5% removal of soluble reactive phosphorus (SRP), and 42% removal of total phosphorus (TP). The wetlands with low hydraulic loading and deep water resulted in creating soils with the highest nutrient concentrations and greatest crop yield. However, loading rates and nutrient retention in the experimental conditions were not sufficient to rival corn growth in fertilized agricultural fields. Nevertheless, the wetlaculture approach provides ecosystem services such as water quality improvement, wetland habitat values, and carbon sequestration, in addition to food production.
