Best Management Practices & Water Resources

Background

UF/IFAS researchers at the EREC initiated field lysimeter studies in 1986 that ultimately lead to the development of BMPs for reducing P concentrations and loads in the EAA. From these studies it was determined that fertilizer practices and a combination of improved drainage uniformity and a reduction in drainage pumping could yield significant reductions in P concentrations and loads for all EAA crops. Using the results of these studies, and best professional judgment available at the time, expected reductions in P loading were attached to each BMP. It was hypothesized that P load reductions ranging from 20 to 60% could be realized for individual EAA farms and for the EAA basin as a whole. The BMPs suggested by the UF/IFAS research and others proposed by industry and the SFWMD, were selected by the SFWMD for inclusion into a table of BMP options for EAA growers. The BMP table was part of a regulatory program initiated by the SFWMD to comply with specific requirements of the state mandated Rule 40E-63, F.A.C. Mandatory BMP implementation in the EAA started in January 1995.

In 1992, the UF/IFAS researchers started a wide-scale implementation and BMP efficacy verification project aimed at quantifying the load reductions that could be achieved at the farm level. Ten farms located through out the EAA were selected as being representative of soils, geographic location, crop rotations, and water management philosophies. Best management practice packages were developed for each farm and implemented. Monitoring of farm drainage volumes and total P concentrations of drainage waters began in Water Year 1993 (May 1, 1992 to April 30, 1993). Water quality and BMP implementation data was collected from all ten farms until 2000 when the number of farms monitored by the project was reduced to seven. In January 2002 the number of farms monitored was further reduced to three, however the level of monitoring at these three farms was intensified to collect and analyze hourly drainage water samples for total suspended solids and total, dissolved, and particulate P concentrations.

All indicators of BMP efficacy have shown that consistent and sustained reductions in total P concentrations and loads occurred due to the implementation of BMPs in the EAA. Basin-level numbers presented annually by the SFWMD reinforce the effectiveness of the BMP program, showing a sustained 50% reduction in total P loading from the EAA. In WY 2004, the TP load reduction from the EAA was 64% compared to the pre-BMP baseline period. The three year average load reduction is 55%. Phosphorus concentrations have also been reduced. In WY 2004, P concentrations from the EAA averaged 69 ppb compared to the pre-BMP base period P concentration of 173 ppb. This major and sustainable reduction is directly attributable to the BMP program. Adjusted unit area loads on project farms averaged 0.73 lbs total P/acre after BMP implementation compared to 1.30 lbs total P/acre prior to WY95. This represents a project average reduction in adjusted unit area loads of approximately 44% which approximates the overall EAA basin load reduction.

The implementation of BMPs successfully reduced P loads leaving the EAA, however there were other water quality concerns besides P specified in the The Everglades Forever Act (EFA) of 1994 that required attention of water managers and researchers. The goals of assessing other water quality concerns was to evaluate the constituents that have been previously identified as elements of water quality concern that will likely not be significantly improved by the Storm Water Treatment Areas (STAs) and current Best Management Practices being widely implemented throughout the EAA, and to identify strategies needed to address such parameters. These parameters were identified by the Florida Department of Environmental Protection (FDEP) as specific conductance, particulate P, and the pesticides Atrazine and Ametryn. The Everglades Agricultural Area-Environmental Protection District (EAA-EPD) and the SFWMD are responsible for the monitoring of Atrazine and Ametryn in waters leaving the EAA basin. The UF/IFAS implemented a research project to investigate the specific conductance and particulate P issues in the EAA. These two studies were completed in 2004; summaries of Specific Conductance and Particulate phosphorus technical reports are found on the Technical Report Summary page of this website.

Current Research

• Implementation and Verification of BMPs To Reduce EAA Farm P Loads
• Synoptic sediment collection and analysis investigation of the primary canals in two of the Eastern sub basins.
• Water and Livelihood Initiative (WLI) in Middle East
• NELAC Certified Laboratory
• BMP Training and Workshops

Implementation and Verification of BMPs To Reduce Everglades Agricultural Area Farm P Loads:Floating Aquatic Vegetation Impact on Farm P Load:

The goal of this research is improved management of floating aquatic vegetation (FAV) in Everglades Agricultural Area farm canals. The hypothesis of the research is that FAV-free canals will be found to produce more cohesive, less reactive sediments due to increased light penetration resulting from the change in farm canal aquatic plant community.

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Synoptic sediment collection and analysis investigation of the primary canals in two of the Eastern sub basins.

The objective of this research is characterize the sediments in the Eastern EAA Sub-Basins at two major canals: the West Palm Beach and the Hillsborough Canals during the wet and dry season.

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Water and Livelihood Initiative (WLI) in Middle East.

The goal of the WLI is to improve the livelihoods of rural households and communities in areas where water scarcity, land degradation, water quality deterioration, food security and health problems are prevalent in the seven participating countries (Egypt, Syria, Lebanon, Jordan, Palestine, Iraq and Yemen), focusing initially on specific benchmark sites. This project is directed by ICARDA (International Center for Research in the Dry Areas) and funded by USAID (US Agency for International Development). There are 7 participating US universities (U of Florida, U of California, Davis, U of California, Riverside, Texas A&M, Utah State U, and U of Illinois). In addition, there are several Middle Eastern Universities participating.

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NELAC Certified Laboratory

The water quality laboratory of the IFAS Everglades Research and Education Center (EREC) has been certified by the State of Florida Department of Health (FDOH), Bureau of Laboratories upon successful on-going compliance with the National Environmental Laboratory Accreditation Conference (NELAC) standards since 2000.  It has been continually complied with Florida Administrative Code (FAC) 64E-1 regulations for the examination of environmental samples in the category of general chemistry no-potable water.  An attestation of compliance with the NELAC standards and the FAC 64E-1 regulations has been renewed annually to maintain the effectiveness of the NELAC Accreditation.  Proficiency test samples from Environmental Resource Associate were analyzed and results reported to the FDOH twice  yearly.  In addition, our laboratory has also been involved in the Everglades Round Robin Inter-laboratory comparison program initiated by the Florida Department of Environmental Protection since 1995 for the purpose of assessing the comparability of phosphorus data from laboratories engaged in the analysis of samples from the Everglades research.  The state laboratory ID of this laboratory is E76463, and the EPA Lab Code is FL00912.  Quality assurance objectives and quality control procedures are specified in a laboratory quality manual and the laboratory standard operation procedures, which are updated maintained by a QA officer on a timely basis.  Quality control criteria regarding P determination and specific conductance sensor drift or biofouling are: Total P > 0.01 mg L-1; total dissolve P > 0.01 mg L-1; particulate P > 0.01 mg L-1; and specific conductance < 0.1 dS m-1 at 1.413 dS m-1 (0.01 M KCl).  For more information regarding the QA/QC of the laboratory or the certification of the laboratory, please contact Dr. Samira Daroub at (561) 993-1593.

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BMP Trainings and Workshops

The objective of this activity is to enhance the dissemination of existing BMPs to all growers in the EAA. The BMP workshops and seminars will be conducted for groups of growers. These venues emphasize the importance of correct BMP implementation and introduce new and effective implementation techniques as they become available.  Following are the activities associated with this project task:

• BMP implementation workshops and seminars. We will continue to conduct workshops for groups of growers. A total of 7 to 9 workshops are normally conducted per year. One to three workshops will be held for each of the major grower entities to ensure complete participation.  In addition, a general workshop open to all will be held once a year to make sure all growers have the opportunity to participate. An open, general BMP workshop conducted in Spanish is scheduled for the fall of 2006.
• BMP extension publications. We produce electronic presentations for BMP workshops, extension personnel, and others involved in enhancing EAA water quality. Also produced are online extension web pages explaining effective BMP implementation in the EAA. The extension publications include a complete description and explanation of the SFWMD's BMP table, as well as information about UF/IFAS research results concerning the control of particulate P transport including aquatic weed management, reducing velocities in canals, and maintaining minimum canal levels. These documents are available at the UF/IFAS EDIS website.
• Pesticide training continues through the IFAS extension office in Belle Glade. We also continue to educate growers in the wise use of Amertryn and Atrazine during every phosphorus BMP workshop that we conduct.

Personnel

Panel 3. GROUP PHOTO.

1. Dr. Samira Daroub - Professor
2. Dr. Timothy Lang - Research Associate
3. Dr. Andres Rodriguez - Post Doctoral Associate
4. Viviana Nadal - Chemist III
5. Irina Ognevich - Sr. Chemist
6. Johnny Mosley, II - OPS

Previous Research

Previous Research

• Particulate P Demonstration Farm
• BMP Consultation Program
• Loxahatchee National Wildlife Refuge
• Farm Verification of BMP Efficacy
• Effects of BMPs on Crops and Soils
• Specific Conductance in EAA Farm Canals
• Particulate Phosphorus Transport and Control

Particulate P Demonstration Farm

The University of Florida's Everglades Research & Education Center created a BMP demonstration sugarcane farm at the research center in Belle Glade, Florida. The BMP farm was established to demonstrate to growers the operational differences between an optimized BMP sugarcane farm and a conventional BMP sugarcane farm.  The main objectives of the demonstration farm are to apply flow velocity and floating aquatic weed controls to effectively demonstrate to EAA growers the resultant P load reductions. 

Two hydraulically isolated sugarcane blocks of 125 and 200 acres each were segregated and equipped with identical drainage pumps and monitoring instrumentation to record rainfall, flow, canal levels and to collect discrete hourly drainage water samples.  Demonstration farm data, i.e., drainage volume, P species concentrations, total suspended solids, canal levels, flow velocities, and rainfall are collected and analyzed to assess and demonstrate the effectiveness of floating aquatic weed management and drainage canal velocity control on reducing particulate, dissolved, and total P farm loads.

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BMP Consultation Program

Project researchers consult with growers in the S-5A sub-basin on their farm specific BMP implementation techniques during the period of May 5 to June 6. The S-5A basin is comprised of a wide variety of growers, so this will provide us a diversified group to develop and improve our operational expertise.  There are currently 82 permitted structures and 53 farm basins in the S-5A basin.  From June 6 onward we will begin consultations with growers farming in the S-6 sub-basin.

The goal of the program is to achieve further basin P load reductions by improving implementation of existing BMPs. The consultation methodology consists of an initial contact and program explanation, one or more field visits to complete a farm BMP appraisal, a discussion with the grower of issues that confront implementation of BMPs on their farm, an analysis of information provided by grower, and a follow up visit for conveying recommendations. Extension materials developed by UF/IFAS that explain in detail the BMPs in the SFWMD's table are distributed when appropriate.  Summary reports of all consultations will be compiled, reviewed by a BMP advisory committee, and included in the project's annual report.

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Loxahatchee National Wildlife Refuge: Impact of Canal Sediments on Water Quality

This project integrates with existing monitoring projects in the Loxahatchee National Wildlife Refuge performed by other scientists.  This project is divided into two tasks: Task 1 is designed to monitor changes in the surface elevation of sediments within the L-40 canal prior to and following commencement of discharge from the STA-1E discharge pump and Task 2 is designed to study changes in water quality by sampling water as it flows along the L-40 canal.  It is conjectured that water flow induced by the STA-1E pump station or other sources may, at times, entrain sediments resulting in erosion of the sediment surface and deterioration of the water quality at downstream locations.  These studies will provide a better understanding of conditions that can result in deterioration of water quality.  These studies and associated activities may identify the need for adaptation of STA discharge operations or for additional structural changes (e.g. dredging).

Task 1: Hydrographic surveys on L-40 canal near the STA-1E discharge.

Five canal cross-sections, above and below the STA-1E discharge have been selected for this study.  Relative surface water elevation is determined by tapedown measurements from a mark on the interior permanent post to the water surface at each section during each visit.  Depth to sediment from the water surface is determined from a boat.  Initial measurements across each transect have bee done at 2.5 ft increments.  Subsequent surveys are being measured at five standardized locations (30, 40, 50, 60, and 70 ft from the interior post), across each transect.  Measurements will be performed at least six times per year over three years.

Task 2: Synoptic water quality research studies on l-40 canal.

This task will survey water quality and other relevant parameters in the L-40 canal on selected dates.  Each water quality survey will sample sites upstream and downstream of the STA-1E outfall.  These data will be used to evaluate the relationship of water quality to canal water velocity, as well as effluent and marsh water quality.  Where feasible the water quality survey will follow the Lagrangian (plug-flow) sampling design that makes observations and draws samples based on time-of-travel to each sampling site.

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Farm Verification of BMP Efficacy

Best management practices have been extremely effective in reducing P concentrations and loads emanating from farms in the EAA.  The farm-level reductions appear to be reflected in basin-level monitoring data produced by the SFWMD.  The BMP studies have shown that water management and crop rotation practices have the greatest effects on farm drainage water P concentrations and loads.  Relative to water management, it appears that achieving uniform drainage across a farm is an extremely effective practice.  Additionally, hydraulically blocking farms and using booster pumps can reduce P concentrations and loads by aiding in achieving uniform drainage, avoiding over-drainage, and disallowing the direct off-farm discharge of water from fields with higher P concentrations.  The crop rotation BMP is tied closely to the water management BMPs.  Rotating crops between hydraulically separated blocks allows for the redistribution of waters with high P concentrations to sugarcane fields.  It also ensures that crops that require more intensive water management are adequately cared for while not over- or under-draining the rest of the farm.

Rainfall adjusted farm-level load reductions, expressed as the SFWMD adjusted unit area load (AUAL), averaged 44.8% for the project sites.  Unit area loads (UALs) per unit of rainfall increased by an average of 10.7% based on WY 1993-1994.  Drainage pumping volume per unit of rainfall decreased by an average of 11.2%.  Total-P concentrations decreased by an average of 7.2%.  While these reductions were occurring at the farm-level, EAA basin-level AUALs decreased by approximately 50% and total-P concentrations declined by 7.8%.  Continued research leading to the development and implementation of BMPs is a requisite for compliance with Rule 40E-63.

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Effects of BMPs on Crops and Soils

A large-scale lysimeter demonstration project was started in December 1997 to understand the efficacy of various proposed BMP strategies and potential impacts of BMP implementation on long-term soil fertility and crop production trends.  The lysimeter site included 25 lysimeters: 11 smaller units dedicated to vegetable (crisphead lettuce) and rice cropping systems and 14 larger units planted to sugarcane.  The sugarcane lysimeter assessment was designed to demonstrate the effects of higher than traditional water table (WT) levels (that occur under BMP implementation) on 3 popular sugarcane cultivars as well as the effects of delivering nutrient-rich drainage waters (P-fertigation) to sugarcane.  The vegetable/rice lysimeter study was designed to demonstrate short- and long-term soil fertility and crop nutrient uptake trends for different vegetable/rice/flooded fallow crop rotations.  Drainage waters from the vegetable/rice lysimeters served as the P-fertigation source into select sugarcane lysimeters.

Averaged across all lysimeter treatments for the entire duration of the 36-month study period the vegetable/rice P export (122 lbs P/ac) was almost eleven times greater than the P amount exported by sugarcane (11 lbs P/ac). This large difference arose from the great difference in fertilizer P input into the two systems.  The vegetable/rice treatment received approximately 6.6 times greater fertilizer P input than the sugarcane treatments.

Water extractable P soil test values in the sugarcane lysimeters did not change appreciably over the course of the project and the treatment that included vegetable irrigation waters did not show any marked increase in soil test P. Water extractable soil test P levels for the vegetable/rice treatments increased while fertilizer P was being applied at high rates, but once water extractable soil P levels reached a plateau (-40 lbs P/ac), resultant fertilizer P additions were subsequently reduced, soil P levels decreased to approximately 30 lbs P/ac.

Depth of water table had no effect on P load exported from sugarcane grown under two water table regimes, 18 to 24 inch and 14 to 20 inch water tables.  The sugarcane treatment that received vegetable drainage water exported 2.7 times more P in drainage waters than sugarcane that did not receive vegetable drainage water. From this field lysimeter assessment it appears that routing vegetable and rice drainage waters through sugarcane fields is an effective practice to lower vegetable drainage water P loads, but is somewhat limited by the timing and intensity of the specific rainfall event and the stage of growth of the sugarcane receiving the drainage water.

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Specific Conductance in EAA Farm Canals

Specific conductance was monitored at ten EAA farms (12 pump structures). All data were collected using Hydrolab DataSonde (series 3, 4, and 4a) multi-parameter water quality data loggers. In order to identify the specific ions and ion ratios that comprise specific conductance, weekly grab samples were taken in 2001 and 2002 from eight farms (10 pump structures) and analyzed for ionic composition. Summary statistics showed that mean specific conductance above 1.275 mS/cm occurred at only two out of the ten farms monitored. Higher concentrations of sodium (Na+) and chloride (Cl-) were also observed at these two farms. Of the two farms, one also showed high levels of sulfate (SO42-).

Potential sources of specific conductance were evaluated. These included geological influences, drainage pumping, irrigation water and fertilizer application. Comparing average specific conductance data points of the study sites to historical Cl- concentration maps of shallow groundwater revealed that the highest average readings occurred on a farm located over historically high Cl- concentrations in 20-50 ft ground water. The farm with the second highest average specific conductance readings was located in an area that has wells of high Cl- concentration. The Na/Cl ratio in the farm canals ranged from 0.57 to 0.78. The Na/Cl ratio in seawater is 0.55. It has been reported that connate seawater underlies the area and exchanges with the surface water where canals are cut into the limestone. Shallow ground water hydrology and quality has a major impact on specific conductance in the EAA.

The effect of drainage pumping on specific conductance was variable and site specific. There was a low correlation between drainage pumping and conductance when all the sites were combined. Irrigation had a low negative correlation with specific conductance. Statistical analysis of the daily average specific conductance at three intensively monitored farms indicated that drainage pumping increased specific conductance at two farms, but not at the third. Irrigation decreased specific conductance at all three farms.

Previous research in the EAA indicated that potassium chloride (KCl) fertilizer application contributed less than 3% to the total dissolved solids (TDS) concentrations in canal waters. It is also reported that a sugarcane crop at harvest takes up more P and K from the soil than that applied by fertilizers. Our results show KCl fertilizer application in one of the high conductance farms with mixed cropping systems contributed less than 6.5% of the TDS in drainage water. This was calculated assuming that all the KCl fertilizer ended up in the drainage water which is highly unlikely as crops take up K+ and Cl- in large quantities.

Specific conductance in the EAA canals is strongly influenced by the composition of the shallow ground water, historically reported to be high in Na+ and Cl- due to connate seawater entrapment and the mixing of surface and ground water. The effect of drainage pumping was variable and site specific. Irrigation, in general, decreased specific conductance. Canal specific conductance is governed mainly by the quality and the hydrology of the underlying shallow ground water, which is farm specific. Fertilizers contributed a very small percentage to the total dissolved solids in the drainage water therefore had no substantial contribution to specific conductance in the EAA. Current P load reduction BMPs have reduced specific conductance in some locations in the EAA. It was the conclusion of this study that no further BMPs can be identified by additional research that would provide abatement of specific conductance in the discharge in the EAA. The issue of specific conductance in the EAA is a geological one, and shallow ground water is the major factor controlling the level of specific conductance in the EAA farm canals.

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Particulate Phosphorus Transport and Control

Particulate P accounts for 20% to 70% of the total P load exported from EAA farms and is frequently the cause of spikes in farms total P loads. The conclusions from our earlier studies suggests that a significant fraction of the particulate P in the EAA originates from in-stream biological growth rather than from field soil erosion. Recently deposited biological sediment material such as settled plankton, filamentous algae, and macrophyte detritus is the fraction that contributes the most to particulate P export. Exported solids may also be contributed directly from loosely bound material detached by turbulent shear forces of floating aquatic vegetation. Other contributions to particulate P loads come from submerged aquatic vegetation and planktonic growth. One of the primary goals of this study was to identify conditions that cause increased particulate P load rates, and analyze those conditions to determine operating procedures that may be optimized to reduce particulate P export, and therefore overall P export at the farm level. Load rate is the product of flow and concentration over a given unit time period.

The particulate P demonstration study was conducted on three farms in the EAA: a sugarcane farm in the northern EAA (UF9200A), a mixed-crop operation in the eastern EAA (UF9206A&B), and a sugarcane farm in the western EAA (UF9209A). Each pump station was fully instrumented, and data was continually recorded for key parameters such as rainfall, pump flow rates, and inlet and outlet water levels. All pump stations are equipped with ISCO 3700 portable automatic samplers that collect water samples every 15 or 30 minutes and composite them into one- or two-hour discrete samples for analysis. All collected samples are analyzed for total suspended solids (TSS), total P, and total dissolved P (TDP). Particulate P is calculated as the difference between total P and TDP. The complexity and the diversity of the systems included are considerable. The approach that has been adopted here was to conduct various forms of cluster analysis to attempt to identify primary parameters that have had the most impact on particulate P transport at the study farms. Event analysis was conducted on the fraction of the total P load contributed by particulate P for each pump station over the four-year study period. The annual contributions from the particulate P loads to the total P loads have decreased in two of the three farms in 2003. Particulate P at UF9200A decreased from an average of 50% over the last three years (2000-2002) to 28% in 2003. The particulate P load contributions of UF9206A increased from 26% in year 2000 to 36% in years 2001 and 2002, and decreased to 27% in 2003. Particulate P load contributions from farm UF9206B decreased from 40% in 2000 to an average contribution of 36% during the last three years. At UF9209A the contribution from particulate P to total P load was almost constant, around 67% in 2001 and 2002. In 2003, UF9209A pumped its canals lower and longer than previous years, causing more sediments to be dislodged from the bottom of the canal and transported out of the farm, resulting in a particulate P contribution of 80% to the total P load.

Load Distribution Analysis of the cumulative hydraulic and particulate P loads generated for each farm and year, showed that 50% of the annual particulate P loads was contributed by less than 25% of the hydraulic load. Process Distribution Analysis was conducted to determine the most probable mechanism for particulate P transport in the sub-events that contribute most to the annual loads, i.e. those in the top 50% of the load distribution. The objective of this analysis is to identify conditions that give rise to the increased particulate P transport events. The most distinctive pattern observed from this analysis is the number of farm-years that were dominated by few events. Data over the four-year study shows that six of the 15 farm-years sampled had a single event that contributed 30% or more to the top 50% particulate P load. Three farm-years had two events that contributed a total of 30% or more. Three farm-years had three events that contributed a total of 30% or more. Only two of the 15 farm-years had their load rates distributed such that it took more than three events to contribute a total of 30% or more to the top 50%.

Periodically, large volume (500-1000 liter) composite samples were taken at each of the study farms. These samples were concentrated by sedimentation in the field. The sediment solids were collected and further concentrated in the lab, after which they were analyzed for the same physical and chemical properties as the farm sediments, including bulk density, solids content, particle specific gravity, organic matter content, and P content. Selected samples were analyzed for particle size distribution and settling velocity distribution. The analysis from the concentrated suspended solids (bulk samples) showed that the exported suspended solids volume is relatively small when present in its settled state. However, the contribution to the total annual P load of the farm could be significant. Thus the importance of the suspended solids on the overall water quality of the farm must be considered when solids removal and control plans are being evaluated.

Farm Sediment Surveys were conducted with the objective of determining the P storage in the main canal sediments, to evaluate farm sediments properties, and to monitor changes in sediment character and inventory over time. Quarterly inventories were conducted of canal sediment volume, mass, and P content at each farm. A number of transect locations were set up at regular intervals upstream of the pump station at each farm. Canal sediment surface elevation and depth was determined at each location. Core samples of the sediment were taken at each transect, sectioned and analyzed for key physical and chemical parameters, including bulk density, solids content, particle specific gravity, organic matter content, and P content. The surveys reported cover the 22-month period from November 2000 through August 2002 for UF9200A, UF9206B, and UF9209A. It appears that there was a trend toward sediment accumulation over the study period at UF9206B and UF9209A, while at UF9200A sediment depth remained relatively constant. The P content (on a dry weight basis) typically decreases as depth increases, but the bulk density of the sediment increases as depth increases.

To understand the transport of particulate P in farm canals in the EAA it is necessary to identify and state the primary processes of movement. Major processes identified affecting particulate P movement were first flush, cumulative high velocity, restart flush, particulate phosphorus spike, and pump cycling.

First Flush

The first flush includes biological material accumulated during the quiescent period between pumping events. This highly mobile material causes an increase in the concentration of suspended solids during the first hours of pump events.

Cumulative High Velocity

Cumulative high velocity produces a steadily increasing discharge concentration of suspended solids as the water farther upstream has a longer time to accumulate eroded suspended solids as it moves downstream to the discharge pump station.

Restart Flush

Restart flush is similar to first flush. When pumping is terminated, suspended solids in the canal system settle out in place. If there has been a significant concentration of suspended solids in the downstream reaches of the canal system at shutdown, there will be a high initial concentration in the discharge when the pump is restarted.

Particulate Phosphorus Spike

Particulate P spikes occur occasionally. A particulate P spike is defined when the particulate P concentration for a particular sample is more than twice that of either the preceding or succeeding samples. The spike is assumed to originate from a random release of particulate material from upstream sources, such as a collection of floating macrophytes or a removal of a flow obstruction.

Pump Cycling

Pump Cycling differs from pump restart in that the pump cycles through on-off oscillations over relatively short time periods, e.g. 30 minutes to two hours. This condition occurs when a farm pump is on automatic on-off control that is tied to canal level.

 

The diversity of the farms has allowed a number of observations to be made regarding the importance of various operating parameters affecting particulate P loads. Dominant events started when pumping operations deviated from typical practices, but these deviations were specific to each particular farm. Following is a short description of recommendations to reduce particulate P loads.

Velocity in Canals

Velocity is a key control parameter for reducing particulate P export. Recommended velocities are relative, in that they must be within the operating framework of the configuration of the farm. Velocities should be as low as possible, and velocity excursions should be avoided, regardless of the average or typical velocity of the canal system. Velocities greater than 0.4 m/s (1.3 ft/sec) have been associated with greater transport rates at the study farms. Given the parabolic relationship between velocity and erosion, "slow and long periods" is preferred than "fast and short periods" for pumping a given volume of water.

Pump Cycling and Reduced Run Times

Long-run period cycling of about 8-16 hours, which reduces continuous pumping duration, has been shown to be beneficial in interrupting continued high velocity transport. This was evidenced on farms where the response time of the farm hydraulic system (i.e., the time required from pump start-up to the time when the equivalent of one volume of farm canal water is exported) is greater than the pump cycling period. Short period cycling of one hour or less is detrimental and should be avoided.

Level Control

Control of canal water levels is critical in avoiding major velocity excursions, and also to stay away from large deviations of the normal farm canal velocities. Lack of level control or major changes in minimum canal levels have resulted in dominant events at the two farms that did not practice strict canal water level control. Canal levels should be controlled to give minimum canal depths that do not exceed the maximum velocity recommendation.

Aquatic Weed Control

Weed control programs in the main canals is one of the most productive techniques in reducing the supply of high P content biomass. Physical removal along the entire length of the main canals is expensive to implement and not practical. For that reason, installation of weed-retention booms is recommended to be located at a distance >300 m (984 ft) upstream the main pump station. Spot spraying of weeds closest to the pump station is also recommended. Chemical treatment of major weed infestations will lead to the accumulation of transportable material into the bottom of the canal and is not recommended.

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Journal Articles / Conference Proceedings / Reports

• Bhadha, J.H., Daroub, S.H, Lang, T.A. 2012. Effect of kinetic control, soil:solution ratio, electrolyte cation, and others, on equilibrium phosphorus concentration. Geoderma 173-174: 209-214.

• Daroub, S.H., Van Horn, S., Lang, T.A.  , and Diaz, O.A   2011. Best management practices and long-term water quality trends in the Everglades Agricultural Area. Critical Reviews in Environmental Science and Technology 41 (6):608-632.

• McGroary, P.C.  , Cisar, J.L., Snyder, G.H., Erickson, J.E., Sartain, J.B and Daroub, S.H. 2011. Water use of St. Augustine grass and Bahiagrass under varying nitrogen rates. Agronomy Journal 103:100-106.

• Kwon, H.Y,  Grunwald, S., Beck, H.W., Jung, Y., Daroub, S.H., Lang. T.A ., and Morgan, K.T. 2010.  Modeling of phosphorus loads in sugarcane in a low-relief landscape Using ontology-based simulation. J. Environmental Quality: 39 (5): 1751-1761.

• L. Janardhanan  and Daroub, S.H. 2010. Phosphorus sorption in organic soils in south Florida. Soil Science Society of America J. :74(5): 1597-1606.

• Lang, T.A., Oladeji, O., Josan, M. and Daroub, S.H. 2010. Environmental and management factors that influence drainage water P loads from Everglades Agricultural Area farms of South Florida. Agriculture, Ecosystems, Environment 138:170-180.

• Martin, M. R., Tipping, P.W., Reddy, K. R., Daroub, S.H. and Roberts, K. M. 2010. Interactions of biological and herbicidal management of Melaleuca quinquenervia with fire: Consequences for ecosystem services. Biological Control. 54:307-315

• Kwon, H., Grunwald, S., Beck, H.W.,  Jung, Y., Daroub, S.H., Lang. T.A ., and Morgan, K.T. 2010. Ontology based simulation of water flow in organic soils applied to Florida sugarcane. Agricultural Water Management. 97:112-122.

• Daroub, S.H., Lang, T.A., and Diaz, O.A., and Grunwald, S. 2009. Long-term water quality trends after implementing best management practices in South Florida. J. Environmental Quality. 38:1683–1693.

• Grunwald, S., Daroub, S.H., Lang, T.A., and Diaz, O.A.. 2009. Tree-based modeling of complex interactions of phosphorus loadings and environmental factors”. Science of the Total Environment. 407:3772–3783.

• Arrieta, C., Busey, P. and Daroub, S.H.. 2009. Goosegrass and bermudagrass competition under compaction. Agronomy. J. 101:11-16.

• McGroary. P.C., Daroub, S.H., Wright, A.L., Cisar, J.L., and Snyder, G.H. 2009. The effects of irrigation and nitrogen on St. Augustinegrass color, quality and growth. International Turfgrass Society Research Journal, 11:55-60.

• Roesch, L. F., Fulthorpe, R. R., Riva, A., Casella, G., Hadwin, A. K., Kent, A. D., Daroub, S. H., Camargo, F. A., Farmerie, W. G. & Triplett, E. W. 2007.  Pyrosequencing enumerates and contrast soil microbial diversity. International Society of Microbial Ecology 1: 0283-0290.

• Diaz, O. A.   Daroub, S.H., Stuck, J. D., Clark, M., Lang, T. A ., and Reddy. K. R. 2006. Sediment inventory and phosphorus fractions for water conservation area canals in the Everglades. Soil Science Society of America Journal, 70:863-871.

• Kabengi, N., Daroub, S.H., Rhue, R. D.  2006. Energetics of arsenate sorption on amorphous aluminum hydroxides studied using flow adsorption calorimetry.  Journal of Colloid and Interface Science.297:86-94.

• Kabengi, N., Rhue, R. D and Daroub, S.H. 2006. Using flow calorimetry to determine the molar heats of cation and anion exchange and the point of zero net charge (PZNC) on amorphous aluminum hydroxides. Soil Science. 171:13-20.

• Chen M., Daroub. S.H., and Nadal. V. 2006. Comparison of two digestion methods for determining total phosphorus in canal water. Communications in Soil Science and Plant Analysis 37:2351-2363.
• Chen, M., Daroub, S.H., Lang, T. A., and Diaz, O. A. 2006. Specific conductance and ionic characteristics of farm canals in the Everglades Agricultural Area, Florida. Journal of Environmental Quality. 35:141-150.
• Adorisio, C., C. Bedregal, S. Daroub, P. McGinnes, C. Miessau, D. Pescatore, B. Powell, P. Sievers, S. Van Horn, J. Vega, M. Edwards, and S.K. Xue. 2005. Phosphorus controls for the basins tributary to the Everglades construction project. Consolidated Report, Water Year 2004, South Florida Water Management District, West Palm Beach, FL (peer reviewed).
• Daroub, S.H., T.A. Lang, O.A. Diaz, M. Chen, and J.D. Stuck.  2004.  Annual report Phase XII: Implementation and Verification of BMPs for Reducing P Loading in the EAA and Everglades Agricultural Area BMPs for Reducing Particulate Phosphorus Transport.  University of Florida, EREC, Belle Glade, May 2004.  Submitted to the Everglades Agricultural Area Environmental Protection District and The Florida Department of Environmental Protection.
• Daroub, S.H., T.A. Lang, and M. Chen.  2004. Specific conductance in the Everglades Agricultural Area. University of Florida, EREC, Belle Glade, March 2004.  Final report submitted to the Everglades Agricultural Area Environmental Protection District and Florida Department of Environmental Protection.
• Bedregal C, S. Daroub, B.Donovan,E. Marshall, P. McGinnes, C. Miessau, D. Pescatore, P. Sievers, J.D. Stuck, S. Van Horn, and J. Vega. 2004. Performance and Optimization of Agricultural Best Management Practices, Everglades Consolidated Report, Water Year 2003, Chapter 3, South Florida Water Management District, West Palm Beach, FL (peer reviewed).
• Daroub, S.H., J.D. Stuck, T.A. Lang, and O.A. Diaz, and M. Chen.  2003.  Annual report Phase XI: Implementation and Verification of BMPs for Reducing P Loading in the EAA and Everglades Agricultural Area BMPs for Reducing Particulate Phosphorus Transport.  University of Florida, EREC, Belle Glade, April 2003.  Submitted to the Everglades Agricultural Area Environmental Protection District and The Florida Department of Environmental Protection.
• Sievers, P., D. Pescatore, S. Daroub, J.D. Stuck, J. Vega, P. McGinnes, and S. Van Horn. 2003. Performance and Optimization of Agricultural Best Management Practices, Everglades Consolidated Report, Water Year 2002, Chapter 3, South Florida Water Management District, West Palm Beach, FL (peer reviewed).
• Stuck, J. D, T.A. Lang, O.A. Diaz, S.H. Daroub, and T. Aziz.  2002. Studies on particulate phosphorus sources and potential management practices for control in the Everglades Agricultural Area. Proceedings of the 7th Biennial Conference on Stormwater research and watershed management, Southwest Florida Water Management District and Florida Department of Environmental Protection. 7th Biennial Conference May 22-23, 2002
• Rice, R.W., F.T, Izuno, and R.M. Garcia.  2002.  Phosphorus load reductions under Best Management Practices for sugarcane cropping systems in the Everglades Agricultural Area.  Agric. Water Manage.  56(1):17-39.
• Izuno, F. T., and R.M. Garcia. 2002. Subsurface drainage systems. In Encyclopedia of Agricultural and Food Engineering. Marcel Dekker, New York, NY.
• Daroub, S.H., J.D. Stuck, R.W. Rice, T.A. Lang, and O.A. Diaz.  2002.  Annual report Phase X: Implementation and Verification of BMPs for Reducing P Loading in the EAA and Everglades Agricultural Area BMPs for Reducing Particulate Phosphorus Transport. University of Florida, EREC, Belle Glade, March 2002.  Submitted to the Everglades Agricultural Area Environmental Protection District and Florida Department of Environmental Protection.
• Davis, W., and M. Chen.  2002.  Everglades Research & Education Center Standard Operation Procedures. Everglades Research & Education Center, Institute of Food and Agricultural Sciences. University of Florida, Belle Glade, FL. December 2002.
• Chen, M.  2001. Quality manual for the laboratory of EREC. Everglades Research & Education Center, Institute of Food and Agricultural Sciences.  University of Florida, Belle Glade, FL. December 2001.
• Izuno, F.T., J.D. Stuck, R.W. Rice, T.A. Lang, and O.A. Diaz.  2001.  Annual report Phase IX: Implementation and Verification of BMPs for Reducing P Loading in the EAA and Everglades Agricultural Area BMPs for Reducing Particulate Phosphorus Transport.  University of Florida, EREC, Belle Glade, March 2001.  Submitted to the Everglades Agricultural Area Environmental Protection District and The Florida Department of Environmental Protection.
• Stuck, J.D., F.T. Izuno, K.L. Campbell, A.B. Bottcher, and R.W. Rice.  2001. Farm-level studies of particulate phosphorus transport in the Everglades Agricultural Area. Trans. ASAE 44(5):1105-1116.
• Stuck, J.D., F.T. Izuno, N. Pickering, K.L. Campbell, and A.B. Bottcher.  2001. Mathematical modeling of suspended solids and particulate phosphorus transport in farm conveyance systems of the Everglades Agricultural Area. Trans. ASAE 44(5):1117-1126.
• Izuno, F.T., and R.W. Rice.  2000.  Annual Report Phase VIII. Implementation and Verification of BMPs for Reducing P Loading in the EAA and Sustainable Agriculture Coupled with Farm-Level P Reduction BMP Implementation. University of Florida, EREC, Belle Glade, May 2000.  Submitted to the Everglades Agricultural Area Environmental Protection District.
• Izuno, F.T., and R.W. Rice.  1999.  Annual Report Phase VII. Implementation and Verification of BMPs for Reducing P Loading in the EAA and Sustainable Agriculture Coupled with Farm-Level P Reduction BMP Implementation. University of Florida, EREC, Belle Glade, June 1999.  Submitted to the Everglades Agricultural Area Environmental Protection District and The Florida Department of Environmental Protection.
• Izuno, F. T. and P.J. Whalen. 1999. Phosphorus management in organic (histosols) soils. In: Phosphorus Biogeochemistry in Subtropical Ecosystems. K.R. Reddy et al, eds. CRC Press Boca Raton, FL.P. 425-445.

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Extension Publications

• Diaz, O.A., Daroub, S.H., R.W. Rice, T.A. Lang, and M. Chen. 2006. Best Management Practices in the Everglades Agricultural Area: Fertilizer Spill Prevention. Institute of Food and Agricultural Sciences, Extension office, University of Florida, Gainesville.
• Daroub, S.H., O.A. Diaz, T.A. Lang, and M. Chen. 2005. Best Management Practices in the Everglades Agricultural Area: Soil testing. Institute of Food and Agricultural Sciences, Extension office, University of Florida, Gainesville.
• Lang, T.A., S.H. Daroub, O.A. Diaz, and M. Chen. 2005. Best Management Practices in the Everglades Agricultural Area: Fertilizer Application Control. Institute of Food and Agricultural Sciences, Extension office, University of Florida, Gainesville.
• O. A. Diaz, T.A. Lang, S.H. Daroub, and Chen. M. 2005. Best Management Practices in the Everglades Agricultural Area: Controlling particulate phosphorus and canal sediments. Institute of Food and Agricultural Sciences, Extension office, University of Florida, Gainesville.
• Daroub, S.H., J.D. Stuck, T.A. Lang, and O.A Diaz.  2002. Particulate phosphorus in the Everglades Agricultural Area: I - Introduction and Sources.  Institute of food and Agricultural Sciences, Extension Office, University of Florida, Gainesville.
• Daroub, S.H., J.D. Stuck, T.A. Lang, and O.A. Diaz.  2002. Particulate phosphorus in the Everglades Agricultural Area: II - Transport Mechanisms.  Institute of food and Agricultural Sciences, Extension Office, University of Florida, Gainesville.

Newsletter Articles

• Daroub, S.H.  2003. Phosphorus reduction in the Everglades. Nonpoint Source News-Notes, May 2003, # 71. United States Environmental Protection Agency, Washington DC.
• Daroub, S.H.  2002. Best Management Practices to improve water quality in the Everglades Agricultural Area (EAA).  Myakka 2/1, Soil & Water Science Department publication, University of Florida.
• Daroub, S.H.  2002. Research and Extension work in the nutrient management and water quality area in the EAA. UF/IFAS Nutrient Management Education Core Group 3.

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National Meetings Abstracts

• Daroub, S.H., M. Chen, and T.A. Lang.  2004. Factors influencing specific conductance in the Everglades Agricultural Area canals.  American Society of Agronomy, Crop Science Society of America and Soil Science Society of America Annual meetings Abstracts, Seattle, WA.  CDROM November 2004. Lang, T.A.S.H.
• Daroub, and O.A. Diaz.  2004. Managing drainage flow velocity and aquatic weeds to reduce P export from Everglades Agricultural Area farms. American Society of Agronomy, Crop Science Society of America and Soil Science Society of America Annual meetings Abstracts, Seattle, WA. CDROM November 2004.
• Daroub, S.H., J.D. Stuck, O.A. Diaz, M.W. Clark, and K.R. Reddy.  2003. Impact of water conservation area canals on low-phosphorus water discharged from storm treatment areas. American Society of Agronomy, Crop Science Society of America and Soil Science Society of America Annual meetings Abstracts, Denver, CO. CDROM November 2003.
• Chen, M., T.A. Lang, and S.H. Daroub.  2003. Specific conductivity trends at monitoring sites in the Everglades Agricultural Area. American Society of Agronomy, Crop Science Society of America and Soil Science Society of America Annual meetings Abstracts, Denver, CO. CDROM November 2003.
• Diaz, O.A., S.H. Daroub, J.D. Stuck, and T.A. Lang.  2003. Transport mechanisms of dissolved and particulate phosphorus in the water conservation area canals in south Florida. American Society of Agronomy, Crop Science Society of America and Soil Science Society of America Annual meetings Abstracts, Denver, CO. CDROM November 2003.
• Lang, T.A., S.H. Daroub, O.A. Diaz, J.D. Stuck, and F.T. Izuno.  2003. Techniques to reduce particulate phosphorus loads from farms in the Everglades Agricultural Area. American Society of Agronomy, Crop Science Society of America and Soil Science Society of America Annual meetings Abstracts, Denver, CO. CDROM November 2003.
• Daroub, S.H., T.A. Lang, R.W. Rice, and F.T. Izuno.  2002. Phosphorus load reduction under Best Management Practices in the Everglades Agricultural Area.  American Society of Agronomy, Crop Science Society of America and Soil Science Society of America Annual meetings Abstracts, Indianapolis, IN, CDROM November 2002.
• Chen, M. 2002. Agricultural BMPs for water quality and phosphorus reduction in the Everglades. South China Agricultural University. Beijing, China. Dec. 6, 2002. Invited.

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State Meetings

• Daroub, S.H. 2005. Best Management Practices in the Everglades Agricultural Area: A success story. Invited speaker at the Florida State Horticultural Society annual meeting, June 5-7, 2005. Invited
• Daroub, S.H. 2005. Phosphorus origin, transport, management, and BMPs in the Everglades Agricultural Area. Invited speaker at the Soil and Crop Science Society of Florida annual meeting May18-20, 2005. Invited
• Diaz, O.A. and Daroub. S.H. 2005. Best Management Practices to reduce P loading in the Everglades Agricultural Area. Invited speaker at the south Florida community college certified crop advisor workshop, Avon Park, FL. May 2005. Invited.
• Chen, M, S.H. Daroub, T.A. Lang, and T. Aziz. 2004. Specific conductance in the Everglades Agricultural Area.  First National Conference on Ecosystem Restoration, Orlando, FL.  December 6-10, 2004.
• Diaz, O.A., S.H. Daroub, J.D. Stuck, and T.A. Lang.  2004. Transport of dissolved and particulate phosphorus in canal waters downstream of STA-1W. First National Conference on Ecosystem Restoration, Orlando, FL.  December 6-10, 2004.
• Diaz, O.A., and Daroub, S.H. 2004. Best Management Practices to reduce phosphorus loading in the Everglades Agricultural Area. Certified Crop Advisor Training, Southwest Florida Research & Education Center, Immokalee FL. June 4, 2004. Invited.
• Daroub, S.H., Lang, T.A., Chen. M., Diaz, O.A., and Aziz, T. 2004. Particulate phosphorus reduction in the Everglades Agricultural Area. Soil and Crop Science Society of Florida - May 2004, Tallahassee, FL.
• Lang, T.A., S.H. Daroub, R.W. Rice, and F.T. Izuno.  2003. Phosphorus load reduction under agricultural BMPs for south Florida Histosols. Joint Conference on the Science and Restoration of the Greater Everglades (GEER), and Florida Bay Ecosystem Palm Harbor, FL. April 13-18, 2003.
• Daroub, S.H.  2002. Performance and optimization of agricultural BMPs: BMP project overview. The 2003 Everglades Consolidated Report peer review and public workshop hosted by the South Florida Water Management District, West Palm Beach, FL. Sept 24-26, 2002. Invited.
• Daroub, S.H. 2002. Best management practices to reduce P loading in the Everglades Agricultural Area.  Certified Crop Advisor Program; South Florida Community College, Avon Park, FL. 100 attendees, March 20, 2002. Invited.
• Daroub, S.H., and Stuck, J.D.  2002. Particulate Phosphorus Control in the Everglades Agricultural Area. Florida Department of Environmental Protection, Tallahassee, FL. May 15, 2002. Invited.
• Daroub, S.H.  2002. Scope of Work: BMP Research, testing and implementation to address water quality standards. Public Workshop organized by the SFWMD on Chapter 40E-63, FAC, Part III BMP Research, testing and implementation to address water quality standards, Belle Glade, FL. January 30, 2002. Invited.
• Daroub, S.H.  2002.  Specific Conductivity research summary.  Public Workshop organized by the SFWMD on Chapter 40E-63, FAC, Part III BMP Research, testing and implementation to address water quality standards. Belle Glade, FL. January 30, 2002. Invited.
• Stuck, J.D. and S.H. Daroub.  2002. Particulate phosphorus research summary. Public Workshop organized by the SFWMD on Chapter 40E-63, FAC Part III BMP Research, testing and implementation to address water quality standards. Belle Glade, FL. January 30, 2002. Invited.

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Annual Reports

For additional information contact Samira Daroub.

1. Annual Report 2017 - updated
2. Annual Report 2016
3. Annual Report 2015
4. Annual Report 2014
5. Annual Report 2012
6. Annual Report 2011
7. Annual Report 2010
8. Annual Report 2008
9. Annual Report 2007
10. Annual Report 2006
11. Annual Report 2004 Chapter 1
12. Annual Report 2004 Chapter 2
13. Annual Report 2004 Chapter 3
14. Annual Report 2004 - Executive Summary

Miscellaneous Reports

1. Management and Environmental
2. FDEP REPORT FINAL
3. FDEP FINAL EXECUTIVE SUMMARY
4. Specific Conductance Final
5. Specific Conductance Executive Summary

2018

Best Management Practices training presentations (Held September 27, 2018)

1. Vegetación Acuática Flotante Impacto-20180827-VN
2. Buenas Practicas de Manejo de Nutrientes-20180927-JF
3. Detencion de lluvia y drenaje en las fincas BMP-20180927-AM
4. Fósforo en Partícula-20180927-LG
5. Las Mejores Practicas del Uso de Plaguicidas-20180927-MO
6. Mejores Prácticas de Manejo para el Control+Program Regulatorio-20180927-CB
7. Mejores Prácticas de Manejo-20180927-LG
8. Opening Slide-20180927

Best Management Practices training presentations (Held April 2018)

1. BMP Overview
2. Opening Slide
3. BMP Regulatory Program
4. EAA Aquatic Weeds
5. Pesticide BMP
6. Research BMP
7. Sediment Particle Control
8. Selection of Suitable BMP
9. Water Management-

2017

Best Management Practices training presentations (Held on Thursday, September 28, 2017)

1. Agenda Sep 28
2. BMP Regulatory Program
3. BMP Herbicide
4. Water Management BMP
5. Sediment Control
6. Selecting Optimal BMP
7. BMP Training Evaluation

2016

Best Management Practices training presentations (Held on Thursday, September 29, 2016)

1. Hansing BMP Sep 29
2. Van Horn Lake Okeechobee Algae Sep 29
3. McCray Nutrient Control Sep 29
4. Gettys Aquatic Weeds Sep 29
5. Fernandez Wise Use Triaziness EAA Sep 29
6. Lang Sediment Particulate Sep 29
7. Girado Selection Suitable Sep 29
8. Daroub BMP Research Update Sep 29

2016

Best Management Practices training presentations (Spanish session)

(Held on Thursday, September 22, 2016)

1. Entrenamiento Sep 22Entrenamiento Sep 22
2. Asuaje Mejores Practicas Manejo de Pesticidas Sep 22
3. Pernett Programa Regulatorio Sep 22
4. Lang/Lopez Detencion de Agua de Lluvia Sep 22
5. Girado Fosforo en Particula Sep 22
6. Fernandez Buenas Practicas Sep 22
7. Nadal Actualizacion de las Investigaciones Sep 22
8. Girado Workshop Buenas Practicas Manejo Sep 22

2013

Best Management Practices training presentations (Held on Thursday, April 11, 2013)

1. Daroub 40E-63 Expalanation update Apr 11
2. Gettys Herbicide Resistance Apr 11
3. Donovan Practices & Discharge monitoring Apr 11
4. Jerauld Presentation Apr 11
5. Odell Alternative Treatment Systems Apr 11
6. Baucum Wise use of Herbicides Apr 11
7. Glaz Sugarcane Apr 11
8. Howell Discharge Method Apr 11