BMPs (Best Management Practices) in agriculture are a logical control mechanism for lowering the amount of nutrients escaping into the environment. To maximize agricultural production and to minimize its negative impact, apply these common-sense rules wherever fertilizers are used. Fertilization costs money -
Because it is there a limiting mineral nutrient, PHOSPHORUS (P) is the most important element in the Everglades.
At the same time, it is crucial to the agriculture where it substantially improves crop yields. Unfortunately, it washes off the fields and most of it ends up where it creates ecological havoc in the environment.
One of the ways of minimizing this draw-back effect is to improve on the availability of P to the plants and make thus for its more efficient uptake by the crop plants.
Watch this 23-sec. short VIDEO on how AVAIL Fertilizer Advancer does it.
Specifically, BMPs are aimed at improving :
On-farm water management, and -
Minimization of particulate Phosphorus run-off
Best Management Practices (BMPs) - just what are they ?
Agricultural BMPs are practical, cost-effective actions that agricultural producers can take to reduce the amount of pesticides, fertilizers, animal waste, and other pollutants entering our water resources, and to increase water-use efficiencies.
• BMPs are designed to benefit water quality and water conservation while maintaining or even enhancing agricultural production.
• The Florida Department of Agriculture and Consumer Services (FDACS) develops and adopts BMPs by rule for different types of agricultural operations. Most of the BMPs are outlined in specific manuals, which can be found on FDACS website.
Particulate P and sediment control practices are integral to each EAA farm's efforts to reduce its off-farm P loads. • Each type of a BMP is assigned a certain number of POINTS - farmers are expected to commit to a precribed number of points (
for a POINT example Mouse-over/Click HERE) The following can be considered as the main and basic BMP practices:
BMPs reduce sheet erosion, improve water management, retain nutrients.
Farmers select from the following to meet recommended BMP point count :
(Laser) Leveling of fields
Ditch and canal bank berms
Main canal sediment sumps and traps
Sediment sumps in field ditches
Regular canal and field ditch cleaning
Slowed drainage near exit pump stations
Use of cover crops
Installation of raised culverts
Vegetated ditch banks for stabilization
Use of weed booms and trash racks
Highly polluting field run-off, fertlizers inefficiencies and soil erosion result when inadequate BMPs are practiced:
Technological Limits:
The fact remains - we currently do NOT have cost-effective techniques to control and remove P from the environment to low parts per billion (ppb, micrograms/liter) - on a huge scale as necessary for the Everglades.
Pollution from fields into canals -
contaminating surface waters -
causing toxic algal blooms - Proliferation of harmful algae in P-rich waters pours the contamination all the way into the ocean that cannot absorb it any more
without an undue coastal and oceanic ecosystem harm -
AGRICULTURE Mainly -
Fertilizers from pastures and row crops in the Lake Okeechobee watershed pollute the downstream Lake with excessive nutrient (P) run-off. Water clean-up and good water management have to be applied upstream from LO. Important problem is associated with these non-point (dispersed) agricultural pollution sources. Urbanization in the region also contributes a serious pollution load. However, due to its point-source nature, it can be easier controlled. Aquifers in the region are becoming both polluted (spring contamination !) and over-drawn by mainly cattle farmers and food (meat) processors.
LO Watershed - view
LAND USE
and
PHOSPHORUS(mouse-over and/or CLICK)
Some land uses contribute high amounts of "loose" Phosphorus - it escapes into streams and canals feeding LO.
E.g. check high P contributions from "Improved Pastures"
(24.5%)", "Citrus" (18.1%), "Row Crops" (7.8%). Conversely, BIG "Natural Areas" contribute relatively little P.
For the EAA, Florida Constitution stipulates that "Polluters Pay" for water purification. Sugar cane farming is a major pollution source. ( Mouse-over and/or CLICK to enlarge below) :
To more effectively remove Phosphorus, addition of small amounts of inorganic coagulants is used such as: ♦ Ferric chloride
♦ Ferric sulfate
♦ Aluminum chloride
♦ Aluminum sulfate - together with mineral alkalinity sources such as: ♦ Lime
♦ Soda ash
♦ Magnesium hydroxide
♦ Caustic soda This more sophisticated treatment procedure results in P-rich precipitate (flocs) that has to be physically removed, usually by settling (sedimentation).
Not always suitable for farms -
Again, we currently do NOT have cost-effective techniques to control and remove P from the environment to low parts per billion (ppb, micrograms/liter) - on a huge scale as necessary for the Everglades.
US-Sugar Corp. BMPs Claim - is it such a complete success ?
The "Big Sugar" and its huge sugar-cane farming operations in the EAA have been a major source of Phosphorus water pollution mainly through the field run-off. Indiscriminate fertilization is making up for advanced soil oxidation to the point of its significant loss and subsidence. The use of BMPs has been presented, for example, by the US-Sugar Corp.as an important success in P-reduction in the following way :
The U.S. Sugar has pioneered the implementation of special land and water management systems called Best Management Practices (BMPs) developed in partnership with University of Florida’s Institute for Food and Agricultural Sciences to minimize phosphorus runoff.
Since 1995, water flowing from farmlands in the Everglades Agricultural Area (EAA) has achieved phosphorus reductions that were more than the 25 percent reduction required by the Everglades Forever Act.
The South Florida Water Management District reports that for the 2010 monitoring period show a 41 percent phosphorus reduction in the 470,000-acre EAA farming region south of Lake Okeechobee. Over the past 15 years sugar farmers have reduced phosphorus runoff an average of 50%.
The soil in the farming area is naturally very high in phosphorus, as a result of sediment built up by Lake Okeechobee spilling over its banks, which can run off into ground water. Soil sediments — not fertilizer — carried in farm runoff are a potential source of phosphorus in the water. To reduce potential for phosphorous runoff, BMPs include:
• removing phosphorus-containing sediment from canals and ditches before the water leaves Company property,
• refined fertilizer application,
• precise stormwater pumping practices and
• erosion controls, such as laser leveling fields to reduce or stop wind erosion.
Thanks to the Company’s careful water management, U.S. Sugar farming operations contribute four gallons of water to South Florida’s water supply for each gallon they use."
P-reduction by farmers in the EAA (MOUSE-OVER or CLICK the diagram)
Phosphorus MASS BALANCE for the Greater Everglades region
CLICK picture for ENLARGEMENT
FIGURE -
Average annual total phosphorus loading across the South Florida ecosystem for water years 2005-2009.
Schematic Diagram based on the P-mass balance.
Arrow numbers units = metric tons of Phosphorus per year
WCD = Water Control District
ECP = Everglades Construction Project
SOURCE:
SFWMD and FDEP (2008b); Xue (2009, 2010), S. Van Horn, SFWMD, personal communication, 2010
♦ STAs - CONSTRUCTED WETLANDS for Phosphorus removal
Stormwater Treatment Areas are currently being used for Phosphorus control of water that is mainly designated for flowing either into Lake Okeechobee or, and that's the main concern, into the Everglades Protection Area and eventually into the Everglades National Park. STAs require large land areas that have to be purchased (high land costs !) for the construction (expensive too !) and operation of this well controled aquatic system. Invariably, it is mainly the government (taxpayers) who tend to pay for this ultimate water clean-up.
The STA-based water purification system is only one part of the solution aimed at clean water. The polluting P control at the source (farms) is another and extremely important factor that makes a crucial contribution towards the goal - clean water for the Everglades.
