Long-term push–pull cropping system shifts soil and maize-root microbiome diversity paving way to resilient farming system

Abstract

Background The soil biota consists of a complex assembly of microbial communities and other organisms that vary significantly across farming systems, impacting soil health and plant productivity. Despite its importance, there has been limited exploration of how different cropping systems influence soil and plant root microbiomes. In this study, we investigated soil physicochemical properties, along with soil and maize-root microbiomes, in an agroecological cereal-legume companion cropping system known as push–pull technology (PPT). This system has been used in agriculture for over two decades for insect-pest management, soil health improvement, and weed control in sub-Saharan Africa. We compared the results with those obtained from maize-monoculture (Mono) cropping system. Results The PPT cropping system changed the composition and diversity of soil and maize-root microbial communities, and led to notable improvements in soil physicochemical characteristics compared to that of the Mono cropping system. Distinct bacterial and fungal genera played a crucial role in influencing the variation in microbial diversity within these cropping systems. The relative abundance of fungal genera Trichoderma, Mortierella, and Bionectria and bacterial genera Streptomyces, RB41, and Nitrospira were more enriched in PPT. These microbial communities are associated with essential ecosystem services such as plant protection, decomposition, carbon utilization, bioinsecticides production, nitrogen fixation, nematode suppression, phytohormone production, and bioremediation. Conversely, pathogenic associated bacterial genus including Bryobacter were more enriched in Mono-root. Additionally, the Mono system exhibited a high relative abundance of fungal genera such as Gibberella, Neocosmospora, and Aspergillus, which are linked to plant diseases and food contamination. Significant differences were observed in the relative abundance of the inferred metabiome functional protein pathways including syringate degradation, L-methionine biosynthesis I, and inosine 5'-phosphate degradation. Conclusion Push–pull cropping system positively influences soil and maize-root microbiomes and enhances soil physicochemical properties. This highlights its potential for agricultural and environmental sustainability. These findings contribute to our understanding of the diverse ecosystem services offered by this cropping system where it is practiced regarding the system's resilience and functional redundancy. Future research should focus on whether PPT affects the soil and maize-root microbial communities through the release of plant metabolites from the intercrop root exudates or through the alteration of the soil's nutritional status, which affects microbial enzymatic activities.

The Effect of Two Siderophore-Producing Bacillus Strains on the Growth Promotion of Perennial Ryegrass under Cadmium Stress

“…It was also verified that the inoculation of PGPRs significantly increased the nitrogenase activity of Dalbergia sissoo seedlings and promoted its growth [ 51 ]. Phosphorus stands as a crucial nutrient vital for plant metabolism and nutrient cycling, ranking second only to nitrogen in significance [ 52 , 53 ]. One of the most promising avenues for developing durable and secure technology is the application of phosphorus-solubilizing bacteria (PSBs) [ 54 ], which play an important role in phosphorus cycling and promoting plant growth.…”

Maize edible-legumes intercropping systems for enhancing agrobiodiversity and belowground ecosystem services

“…While agricultural intensification aims to enhance agricultural yields, it centered around conventional practices such as monocropping, increased usage of synthetic chemical inputs among others. Addressing these challenges require focusing on ecological intensification including crop diversification, emphasizing on environmental quality, and the role of belowground biodiversity 2 – 4 . One effective strategy of ecological intensification is intercropping, where two or more crops are cultivated simultaneously in the same field, offering numerous advantages 3 – 7 .…”

“…One effective strategy of ecological intensification is intercropping, where two or more crops are cultivated simultaneously in the same field, offering numerous advantages 3 – 7 . Intercropping highlights utilization of resources relying on natural agroecological services, and synergies among plant species to improve the soil and crop yields, reduce environmental risks, and promote agricultural sustainability 2 – 4 , 7 . For example, grains like wheat or maize are often intercropped with legumes because they can fix nitrogen in the soil, benefiting the companion crops 4 , 8 .…”

“…Soil habitat is an ecosystem known for its diverse array of living organisms (especially microbes) and essential micro and/or macro nutrients 7 , 19 – 21 . The rhizosphere offers a favorable habitat for bacteria, fungi, and other organisms to thrive 4 , 17 , 18 . Further, the root microbiome significantly contributes to plant growth and health by facilitating nutrient uptake, improving stress tolerance, and protecting against pathogens.…”

“…The choice of plants for specific cropping systems also plays a significant role in determining the composition of microbes in the rhizosphere, plant root, and soil health by increasing or decreasing their abundance and diversity 20 , 24 . Agricultural practices such as crop rotation, intercropping, cover cropping, and PPT have been shown to increase the microbiome diversity and abundance and soil health by enhancing symbiotic and non-symbiotic beneficial microbial communities 4 , 17 , 25 . On the contrary, monoculture cropping systems contribute to the decline of soil biota and negatively impact soils by increasing erosion and plant pathogens 4 , 26 .…”