MESSAGE FROM THE 2003 EXECUTIVE COMMITTEE, FLORIDA DIVISION
SUGARCANE AND THE EVERGLADES
A GOOD RELATIONSHIP SCIENCE CAN IMPROVE
Our organization agrees with many diverse groups that an effective long-term plan is needed to save the natural Everglades. Sugarcane farming in the Everglades Agricultural Area (EAA) and a sustainable Everglades should not be viewed as two opposing forces. The two are inextricably linked; conceptually, a sustainable agriculture in the EAA and a sustainable Everglades ecosystem are interdependent. We recognize that both the natural Everglades and the farmers in the EAA face many challenges to become both compatible and sustainable in the future.
FACTS CONCERNING THE FLORIDA SUGAR INDUSTRY
Sugarcane is a grass grown primarily for its sugar (sucrose) content. This field crop has been grown commercially in southern Florida since the 1920s and is one of the most economically important crops in the state.
Approximately 450,000 acres are grown annually, primarily around the lower half of Lake Okeechobee. The proximity to the lake is important in that it offers some cold protection to the tender cane during occasional harsh winter weather.
SUGARCANE, MOST SUITABLE FOR THE EAA
Sugarcane planting and harvesting operations are conducted during the fall and winter. This period is typically drier than the summer months. Thus, sugarcane culture is in harmony with the South Florida climate. The cool, dry fall and winter months are good for plant emergence and mature sugarcane ripening.
Once established, sugarcane is far more water tolerant than leafy vegetables or sweet corn. This becomes an asset for summer water management practices. Area farms store water during surplus rainfall periods by maintaining higher water tables in sugarcane fields, flooding vacant vegetable and sugarcane fields, or growing paddy rice. This good soil conservation practice is also a very effective best management practice for phosphorus reduction.
Water that is managed by area farmers is monitored for quantity and quality, and reports are submitted to the South Florida Water Management District monthly. All farmers have responded well under regulatory action and made commendable gains in the management of this valuable and essential resource. EAA farms have achieved a 71% across the board reduction in phosphorus levels in the water discharged from the EAA according to a recent report from the South Florida Water Management District. This reduction exceeds the 25% annual goal required for the entire EAA basin by Florida's Everglades Forever Act.
SUGARCANE USES FERTILIZER EFFICIENTLY
Sugarcane requires only one half the amount of phosphorus needed for sweet corn, one third the amount needed for celery, and only one quarter the amount needed for lettuce.
Sugarcane, like any other plant, requires nutrients for optimum growth. In the EAA, nutrients are provided for plant uptake from rainfall, irrigation water, the organic soils, and supplemental fertilizer. Research by the University of Florida to determine adequate levels of nutrient elements necessary for sugarcane production began in1929. Early research showed that the high levels of phosphorus needed for vegetable production reduced the amount of sugar in the cane stalk. Since then, numerous research studies based on yield responses have established the guidelines currently used for fertilizer rates.
Research studies by Coale et. al. (Agron. J. 85:310-315) showed that sugarcane biomass removes more phosphorus from the soil than the amount applied as fertilizer. This indicates that the sugarcane plant uses not only fertilizer phosphorus but also residual and naturally occurring phosphorus as well.
In another study, Izuno et. al. (Agricultural Best Management Practices (BMPs) for Phosphorus Loading Reduction in the Everglades Agricultural Area (EAA), IFAS, U of F, 11/29/90) showed that less phosphorus was found in drainage water from fertilized sugarcane fields than in the drainage water from adjacent non-fertilized fallow fields.
ROTATION: A NUTRIENT, SOIL CONSERVATION, AND PEST MANAGEMENT TOOL
Sugarcane is planted in rotation with rice, sod, spring and fall sweet corn, radishes, and other assorted vegetables. To maximize the efficient use of plant nutrients in the soil, a rotation from higher to lower fertility requiring crops is normally practiced.
A typical production plan would be for a sweet corn or vegetable crop (9 months to several years) to be followed by one or two sugarcane crops (3-8 years). These would be followed by a summer rice crop. This rotation not only maximizes the use of residual fertilizer, but also follows a decreasing intensity of drainage and pest management requirements.
SUGARCANE IN FLORIDA RECEIVES RELATIVELY LITTLE PESTICIDE
Sugarcane in Florida requires a minimum amount of pesticides. There are several reasons why this is the case. First, sugarcane is relatively tolerant to damage by most pest species. This is especially true with respect to pests which attack foliage. Taking advantage of this tolerance, sugarcane growers have successfully implemented natural control strategies for most pests.
For control of plant diseases, no fungicides (pesticides used specifically for fungal pathogens) are applied by sugarcane growers in Florida. Resistant sugarcane varieties are the single-most important management strategy for the control of bacterial, fungal, and viral diseases.
Natural control of insect pests through the preservation and encouragement of insect parasitoids and predators is recognized as an important tactic of integrated pest management (IPM) . For insects and mite pests of sugarcane, biological control (using predators, parasites, and other beneficial organisms to control pests) has been an outstanding management strategy.
Insect parasites are among the most valuable biological control agents, but a number of common predators are also important. These include earwigs, lacewings, lady beetles, fire ants, and ground beetles, as well as birds such as the cattle egret. Years of cooperative research by private industry, the USDA and the University of Florida, have been conducted to boost biological controls. One large sugarcane company has developed a system for growing beneficial insects and releasing them as a substitute for pesticides to control one of the most important insect pests.
While EPA-approved insecticides may occasionally be required, the use of chemicals in Florida sugarcane is best described as limited. For example, recent estimates indicated that more than 80% of the sugarcane in Florida is often grown without receiving a single foliar pesticide application for insects, mites, or diseases over the course of an entire year.
EAA AMBIENT AIR MONITORING
The Palm Beach County Health Department and the Florida sugar industry have conducted programs of air quality monitoring in the EAA since the late 1960's. These programs are designed to monitor particulate matter, sulfur dioxide, and ozone under sampling protocol and regulations of the U. S. Environmental Protection Agency and the Florida Department of Environmental Protection.
Air quality in the EAA is well within state and federal air quality standards and is comparable to both the statewide and coastal Palm Beach County averages.
Palm Beach County Health Department measurements show that less than 2% of the airborne particulate matter measured at their five monitoring stations is from agricultural origins.
PUBLIC AND PRIVATE GROUPS WORK TO SUSTAIN AGRICULTURE
Public and private sugarcane breeding programs have focused on cultivated sugarcane varieties with high yields and disease resistance. Varieties originating in the EAA have substantially improved sugar production in Florida, Louisiana, Texas, Latin America, and other regions throughout the world.
Geneticists and agronomists are currently broadening their programs to seek varieties that are even more phosphorus efficient and are more tolerant to high water tables. The phosphorus research is two-pronged; isolate the ability to achieve high yields with less phosphorus fertilizer, and select for the ability to remove more phosphorus from the soil.
Research and commercial conditions in the EAA, and other countries, have shown that sugarcane tolerates short-term floods, and that this characteristic could be genetically improved. More water-tolerant sugarcane would have side benefits of enhancing soil conservation efforts and further reduce phosphorus runoff from EAA soils.
AT THE FACTORIES
In Florida, the sugar mills process approximately 17,000,000 tons of sugar cane, from which about 2,000,000 tons of raw sugar and about 100 million gallons of black strap molasses are produced each year. Raw sugar is used by refineries to produce refined sugar.
Chemically classified as a carbohydrate, sugar is a natural energy source. Black strap molasses is normally used for cattle feed or as a feed-stock in the production of alcohol, a renewable fuel.
The production of sugar from cane involves several well established processes: extraction, clarification, evaporation, crystallization, and mechanical separation. None of these processes involve the use of hazardous or environmentally undesirable materials. Current emphasis in the industry is towards improved process control and efficiency.
At the grinding station, juice is extracted by crushing the cane through a series of three or four roll mills. The fiber residue left from grinding the cane, bagasse, is sent to the boilers as fuel. Using bagasse as the renewable fuel makes Florida sugar cane processing operations almost energy self-sufficient.
With the modern boilers now in use, the sugar industry produces a surplus of energy, available as electric power to domestic and industrial users. Flue gas generated during boiler operations has a higher moisture content because the bagasse itself is a moist material. This helps to produce a very clean stack gas which is in compliance with all local and federal clean air laws.
Fuel biomass, bagasse, is almost entirely plant material. The ash from this biomass can be used as fertilizer due to it's high mineral content. Once these materials have been returned to the cane field, a very natural cycle has been completed.
Clarification of the juice is normally carried out with the help of lime and heat in cylindrical tanks. Clarified juice and a precipitate are obtained. This insoluble precipitate, comprised of field soil and plant material, is filtered out and retained in ponds for eventual return to production fields. Again, this completes a natural cycle.
The clarified juice is concentrated in evaporators and seeded with fine sugar powder to serve as nuclei for the sugar crystals. Finally, the crystals, raw sugar, are separated from their surrounding molasses by centrifugal force and sent to storage or to cane sugar refineries.
QUALITY CONTROL IN THE FLORIDA SUGAR INDUSTRY IS STATE-OF-THE ART
The United States cane sugar industry has much more regulatory control than almost all foreign suppliers of sugar. These regulations impact many aspects of operations, including cane production, construction of new equipment and facilities, worker safety, and the environment. If rationally conceived and implemented, such ordinances are desirable for the industry to be a good citizen and neighbor.
Compared to many over-seas milling operations, Florida sugar mill technologists have successfully created a safe and environmentally compatible industry.
Updated from: Journal of the American Society of Sugar Cane Technologists, 1997, Vol. 17: 9-12
return to top