How can changes in soil health impact citrus and other sub-tropical tree crops? That’s a question UF/IFAS researchers hope to answer in a four-year, $500,000 project funded by the U.S. Department of Agriculture National Institute of Food and Agriculture.
Specifically, they will examine how quickly soil health can change in Florida’s sub-tropical sandy soils and how changes in the soil’s health might impact yield.
“Our goal is to help producers by finding out what cover crops do to soil health in Florida groves,” said Sarah Strauss, assistant professor of soil microbiology in the UF/IFAS soil and water sciences department and the lead investigator on the grant project. “While there’s a lot of interest in soil health right now, much of the research and metrics for assessing it are not based on sub-tropical sandy soils like we have in Florida. In order to determine if soil health is improving, growers need to know what the best parameters are to measure. That includes determining which indicators are the most useful for monitoring the soil health of tree crops.”
Sometimes, though, impacts may not be observed for several years. Strauss and her team want to know what indicators can be measured only once a year or more frequently that might show progress even if yield hasn’t changed yet. This would provide grove management information to producers in a more timely fashion.
The team will first measure soil physical, biochemical and microbial parameters involved in carbon, nitrogen and phosphorus cycling at two Florida citrus groves. This provides a detailed assessment of the changes to the soil environment and microbial groups with cover crops. After measuring cover crop impacts on soil in the groves, scientists will see which soil health indicators can carry over to the non-citrus setting. They will also share Florida-specific information with producers.
“In vegetable or row crop systems, cover crops are planted during the fallow season for a few months and then the cash crop will be planted in the same field. That’s not the case for a tree crop, and in Florida, we can keep cover crops growing in the middle of rows between the trees all year,” said Strauss, a faculty member at the UF/IFAS Southwest Florida Research and Education Center in Immokalee. “So, metrics for how quickly things change in the soils for a tree with cover crops may be very different than in a vegetable or cotton field.”
Strauss said they will also compare results with some commercial soil tests to see how indicators relate to what is currently available on the commercial level. Many commercial tests may not provide suggestions or recommendations specific to tree crops.
“Ultimately, this study will provide a list of meaningful soil health indicators that Florida producers can use to meet their unique needs in sub-tropical tree fruit systems,” she said.