A team of UF/IFAS researchers is looking into how changes in soil health impact citrus and other subtropical tree crops. Specifically, they will examine how quickly soil health can change in Florida’s sub-tropical sandy soils and how specific changes in soil health might impact yield. The U.S. Department of Agriculture National Institute of Food and Agriculture is funding the nearly $500,000, four-year project.
“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.”
Improving soil health will hopefully improve productivity. However, sometimes impacts aren’t seen for several years. Strauss and her team want to know what indicators can be measured only once a year or more frequently which might show progress even if yield hasn’t changed yet. This would provide critical grove management information to growers faster.
The team will first measure soil physical, biochemical and microbial parameters involved in carbon, nitrogen, and phosphorus cycling at two Florida citrus groves. This will provide 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.
Row Crops vs. Tree Crops
“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 commercially available. 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.
Joining Strauss in the study are soil and water sciences department colleagues Gabriel Maltais-Landry, assistant professor of sustainable nutrient management systems, and Allan Bacon, assistant professor of environmental pedology. In addition, Danielle Treadwell, associate professor in the UF/IFAS horticultural sciences department, will help expand the scope of the proposed research beyond citrus. Antonio Castellano-Hinojosa, a post-doctoral associate in Strauss’s lab, brings expertise in plant growth-promoting bacteria and their linkage to soil nutrient cycling.
“Growing crops in Florida’s sandy soils is challenging. If we can give producers an efficient, useful management tool, we want to do that,” Strauss said.
This work is supported by the USDA National Institute of Food and Agriculture.