By Sarah Strauss
If you’ve been exploring methods to improve your soil health, chances are you’ve come across the use of cover crops. Even though we call them “crops,” these plants are not harvested and are only planted to improve soil health.
The benefits of cover crops to soil health include increasing soil organic matter and microbial diversity and activity as well as reducing weed growth. There are several ongoing research projects in Florida to determine exactly how cover crops are improving soil health in Florida citrus. So far, cover crops in citrus grove row middles have dramatically improved the abundance and altered the types of microbes in the soil, which can influence nutrient availability.
Cover crops have had a big impact on weed management as they significantly reduce weed pressure. In fact, one of the major benefits to planting cover crops is that it reduces the amount of mowing needed in row middles. If you don’t mow your annual cover crops for several months, you can let them flower and produce seeds for next year, providing you with more seed and saving money on mowing.
Cover crops for citrus can be annual or perennial species. Annual cover crop species include legumes, which can provide nitrogen to the soil, such as sunn hemp, cowpeas and clovers. Non-legume annual cover crops include millet, buckwheat, oats and daikon radish. These can provide soil carbon inputs that can be important for microbial activity and nutrient cycling.
With the rainy season approaching, now is a great time to start thinking about planting annual cover crops. Because cover crops are intended to provide benefits without requiring fertilization or irrigation, timing the planting of your cover crops with the rainy season can be critical for germination and growth. Planting a mixture of annual cover crops at the beginning of the rainy season and toward the end of the rainy season helps ensure the germinating plants have enough water.
Before you plant annual cover crops, you may want to prepare your row middles to provide optimal conditions for germination. Depending on the current weed pressure, herbicides can be applied to the row middles to reduce competition with the germinating cover crops. Annual cover crop seeds can be planted using seed drills or by broadcasting the seeds. Another way to potentially assist cover crop germination is to mow the dead weeds after planting the cover crops. This plant material can help retain soil moisture.
For more details on some of the results from University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) cover crop research, be sure to check out the June issue of Citrus Industry! In the meantime, here are some UF/IFAS Extension publications about cover crops:
- Sunn Hemp — A Promising Cover Crop in Florida
- Questions and Answers for Using Sunn Hemp (Crotalaria juncea L.) as a Green Manure Cover Crop
Sarah Strauss is an assistant professor at the UF/IFAS Southwest Florida Research and Education Center in Immokalee.
Share this Post