Sarah Strauss, a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) soil microbiologist, shared initial results from a UF/IFAS cover crop research trial during the March 23 OJ Break virtual meeting for citrus growers.
According to Strauss, use of cover crops has received increased interest by growers as a method to sustainably and economically improve soil health and crop production.
Cover crops add soil organic matter (SOM), an important undertaking as Florida’s sandy soils in citrus-producing regions often have only 1 to 2% SOM. SOM improves soil’s water-holding capacity, nutrient cycling and retention, and provides nutrients for microbes. Since soil health and plant health act interchangeably, Strauss believes increased soil health aids in the citrus greening fight.
Based on preliminary findings, planting cover crops increased SOM, soil nutrients and microbial activity.
In citrus, cover crops can only be planted in the row middles. However, Strauss found that as citrus roots extend into the row middles, increases in SOM and microbial abundances were found under tree canopies, similar to the numbers found in row middles.
In addition, cover crops reduce weed pressure in treated row middles. Strauss reported weed density being reduced up to 84%.
Strauss says these results appear very promising, despite not seeing any significant differences in fruit quality or tree production. Because of Florida’s extremely low SOM percentage, it may take several years before increases in soil health influence tree health and productivity.
Strauss also conducted a small trial combining compost with cover crops to enhance germination. Two different rates of compost were applied prior to cover crop seeding during the first year of the ongoing project. After examining the data, she reported that there was no significant difference in germination between cover crops alone and combining them with compost.
Read more about cover crops.