by Each summer, nearly 25,000 acres (10,000 hectares) of rice are cultivated in the Florida Everglades Agricultural Area, an area about 1,100-square miles (2,800-square kilometers) south of Lake Okeechobee.
Farming here requires a sensitive touch. The area has lost nearly 6 feet (1.8 meters) of soil over the past century through a process known as subsidence.
One way to slow this subsidence and preserve the nutrient-rich soil is to flood the area during Florida’s rainy season and use the fields to grow rice. The fields are flooded using water from nearby canals. As soon as the water dries up or runs out, the rice is harvested.
The Conversation asked Associate Professor Jehangir Bhadha, an expert on soil sustainability at the University of Florida, how the university was involved in growing rice and what the environmental benefits were.
What is the history behind growing rice in the Everglades?
Rice was grown in the Everglades Agricultural Area for a brief period in the 1950s, but was limited to about 2,000 acres (800 hectares).
Then a rice virus was discovered in Florida called hoja blanca, or white leaf, which stunts the plants or even kills them. This virus was first reported in the late 1950s in Colombia and Venezuela.
Rice made a comeback in Florida in 1977 after growers in the Everglades Agricultural District demonstrated that it could be grown in sugar fields during the summer fallow period from May to August – when it is too hot and too wet in Florida South to grow vegetables. By this point, the hoja blanca disease was under control, and new resistant varieties of rice were developed.
In late spring and summer, more than 50,000 acres (20,000 hectares) of fallow sugarcane land in the Everglades Agricultural Area are available for rice production. In 2023, rice was planted on about half of these acres. The remaining land remains fallow or is flooded but has no rice – a practice commonly known as “fallow flooding”.
On average, each cultivated acre produces about 2 tons (1,800 kilograms) of rice.
What makes rice cultivation in this area different?
Rice cultivation in the Everglades Agricultural Area area requires no initial nitrogen, phosphorus or potassium fertilization because the regional soils are very organic and rich in nutrients.
The area consists of almost 450,000 acres (180,000 hectares) of organic soils known as Histosol. These soils contain up to 80% organic matter, making them unique to the region and a vital resource for its vibrant agricultural economy. Histosols are also sometimes called bog or peat soil.
South Florida’s Histosols were formed over a period of several thousand years when organic matter accumulated faster than it could decompose in the sawdust prairies that thrived in the area south of Lake Okeechobee.
But since the land here was drained for crop production in the early 1900s, organic matter is decomposing faster than it is being replaced. This is mainly due to microbially mediated oxidation. It occurs when organic matter slowly decomposes and is eaten by microbes. This results in a gradual loss of soil and a lowering of the surface elevation.
The soil depth in this area varies from a few inches to up to 5 feet. Underneath the Histosols is a hard limestone bedrock that is not conducive to farming. In many places, the limestone bedrock is exposed on the surface, or pieces of it are incorporated into the soil.
What does growing rice do for the health of the soil there?
By flooding these fields for long periods, growers suppress the microbial activity that causes oxidation and the hatching of pest insects. It also increases the soil’s water-holding capacity, allowing more moisture to be retained during drier periods of the year.
The improved soil health benefits the sugarcane crop and maximizes the longevity of the soil.
Flooded rice growth has also been proven to attract wading birds such as the great white heron, snowy plover and glossy ibis.
What work is your team up to now?
Over the past 15 years, more rice and more varieties of rice have been planted. While only two dominant varieties were planted in 2008 over approximately 12,000 acres (4,800 hectares), more than 10 varieties were planted over 23,000 acres (9,300 hectares) in 2023.
To provide a constant supply of new varieties, researchers and others at the University of Florida’s Institute of Food and Agricultural Sciences, along with Florida Rice Growers Inc., conduct annual rice variety trials to rate new or existing varieties in South Florida. The trials aim to identify high-yielding and disease-resistant varieties of rice that are compatible with the area’s subtropical climate and highly organic soils.
Every summer, the University of Florida IFAS Extension and Research faculty hold a rice field day dedicated to showcasing their current research.
The next rice field day is August 8, 2024, in Belle Glade. It is free to the public with advance registration.
This article is republished from The Conversation, a non-profit, independent news organization that brings you facts and analysis to help you make sense of our complex world.
It was written by: Jehangir Bhadha, University of Florida.
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Jehangir Bhadha receives funding from NSF, USDA, FDACS, Florida Rice Growers Inc.
