Foliar application of bioorganic fertilizer enhances plant nutrients uptake and citrus yield by regulating rhizosphere and phyllosphere microbiome

Decreasing chemical fertilizers and using bio-organic fertilizers (BIOF) are effective strategies for enhancing soil quality, promoting sustainable agriculture, and protecting the environment. However, the impact of foliar application of BIOF on rhizosphere soil properties, microbial communities, and citrus yield remains unclear. This study was set in randomized complete block (RCB) with two treatment, control (CK) and the foliar application of BOF (BIOF) treatment, to investigate the impact of BIOF in citrus orchards for the first time, on soil chemical and biochemical properties, its interactions with microbial communities, and the subsequent impact on citrus yield. Results showed that BIOF significantly increased soil total nitrogen (TN), available nitrogen (AN), total phosphorus (TP), available phosphorus (AP), available potassium (AK), soil organic carbon (SOC), and soil organic matter (SOM) compared to CK. Meanwhile, accompanied by a decrease in soil pH values and increasing essential micronutrients like manganese (Mn), copper (Cu), boron (B), iron (Fe), and zinc (Zn). Furthermore, enzymatic activities such as acid phosphatase, urease, and catalase activities were also increased in BIOF treatment. In citrus leaves, BIOF elevated key nutrient levels and significantly boosted fruit weight (10.25 %, size (29.59 %), fruit count tree(-1) (13.56 %), and total yield tree(-1) (31.95 %). Microbial diversity analysis showed that BIOF altered rhizosphere and phyllosphere microbiomes, increasing beneficial bacteria while reducing pathogens. Mantel-test heat maps confirmed positive links between enhanced soil nutrients and microbial diversity. Overall, foliar application of BIOF enhances soil fertility, enzymatic activity, microbial diversity, and citrus yield, highlighting its potential as a sustainable agricultural practice.