Soil Microbiome Engineering for Enhanced Agricultural Productivity

Abstract

Soil microbiome engineering--the deliberate manipulation of soil microbial community composition and function to augment plant productivity, nutrient cycling, and stress resilience--represents a frontier strategy for sustainable intensification of food production without proportional increases in synthetic agrochemical inputs. This study evaluates four soil microbiome engineering interventions--bioinoculant consortia (BIC), biochar-assisted microbial introduction (BAMI), synthetic community transplantation (SCT), and humic acid-stimulated indigenous microbiome activation (HASIMA)--across wheat, maize, and tomato cropping systems at five sites in Italy, Switzerland, and Spain over three growing seasons (2022-2024). Soil microbiome responses were characterised by 16S rRNA amplicon sequencing (V3-V4, Illumina MiSeq), quantitative PCR for functional genes (nifH, amoA, phoD), and enzymatic activity assays. BIC increased wheat yield by 18.4% and NUE by 22.7% relative to uninoculated control, while SCT produced the largest diversity increase (Shannon H' +1.42) but inconsistent yield responses. BAMI exhibited the most durable microbial community shifts, with inoculant strains detectable at 12 months in 78% of plots. These findings advance understanding of microbiome-yield linkages and inform rational design of microbial soil amendments for precision agriculture.