Organic Orchards Boost Microbial Diversity and Nutrient Cycling Harmed by Pesticides

(Beyond Pesticides, May 12, 2026) Research published in Microbiological Research finds that organic farming enhances microbial diversity in citrus orchard soil systems, both in terms of nutrient cycling and aiding in the development of more complex microbial networks pivotal to biodiversity. This comes as no surprise to organic, public health, and biodiversity advocates who have tracked the scientific literature on soil health and human health benefits of organic land management systems.

Methodology and Results

The international research team for the study engaged in a comparative field study of 15 commercial citrus orchards in Sicily, including 7 organic fields and 8 chemical-intensive, conventional fields, with the prime objective of assessing the role of the farming system, as well as environmental and agronomic factors, on soil microbiome structure and function. They collected 75 samples in summer (June-July 2021) and winter (December 2021-January 2022) periods, with 150 soil samples collected in total. In each orchard, 5 trees were randomly selected, with 4 soil “cores” pooled into one composite sample per tree at a depth of roughly 20-30 centimeters to assess interactions with tree roots and at a distance of 40-100 centimeters from the tree trunk.