Push-pull cropping system soil legacies shifts rhizosphere and root microbiome in maize farming systems and reduce Spodoptera frugiperda larval feeding

Rhizosphere biota varies greatly across farming systems and influences soil health and plant productivity. Push-pull technology (PPT) is an agroecological companion cropping system used for insect-pest management, soil fertility, and weed control and has been adopted by many farmers across sub-Saharan Africa. The impact of this cropping system on belowground microbiome is poorly understood. We examined how conditioning soil with PPT affected rhizosphere and maize-root microbiome, soil properties, maize seed germination and plant growth and subsequent effect on Spodptera frugiperda larval feeding. Rhizosphere soil and maize-root from PPT fields had enriched ecologically important microbiomes which are linked to important ecosystem services like plant protection, carbon utilization, nematode suppression and nitrogen fixation such as Trichoderma, Streptomyces, Nitrospira, Streptomyces, Sphingomonas, RB41 among others compared to maize-monoculture fields. Contrary, maize-monoculture fields had enriched microbial communities associated with plant pathogenesis and food safety such as Bryobacter and Aspergillus. Soil conditioned by PPT exhibited high pH, nitrogen, and phosphorus levels. Maize grown in PPT soil had faster seed germination and higher plant growth rate. Spodoptera frugiperda neonates fed more on leaf tissue from maize grown in maize-monoculture soil than those grown in PPT soil. The findings show that PPT improves soil health including soil microbial communities and enhances maize growth parameters, and Spodptera frugiperda resistance by reducing larval feeding. These findings in soil health are linked to the reduced larval feeding as a measure of direct resistance to a new invasive pest and present new ecosystem services for the push-pull cropping systems.