Challenge of transition: the history of a case study involving tropical fruits polyculture stimulated by humic acids and plant-growth promoting bacteria

Abstract

Background Innovative technologies are required in agricultural production to eliminate the environmental risk generated by the intensive use of fertilizers and pesticides. Soil organic matter is a keystone for the transition towards sustainable production. However, it is not an easy task to increase soil organic matter in highly weathered soils without considerable resources and energy. Here, we highlighted the role of biological inputs in plant adaptation to low fertility and water scarcity. The direct use of humic acids and plant growth-promoting bacteria on plants can modify the root architecture systems, including surface area and roots length, thus allowing greater soil exploration. Material and methods Within a socio-historical perspective of concepts and research methods, a case study is presented on the effects of humic acids applied together with plant-growth promoting bacteria, as an efficient tool for supporting the transition to more suitable production system. We implemented this natural ecological approach onto a polyculture system with different tropical fruits (banana, passion fruit, papaya and pineapple) and evaluated crop yields. Results We observed increases of around 50 and 90% in banana and papaya yield, respectively, and 25% in passion fruit productions, with significantly greater yields maintained over four production cycles. No effect was observed in ananas production probably due to the large shading level in the area. Conclusion The biostimulant formulated with endophytic diazotrophic bacteria and humic acids represents a low-cost technology that enhances crop yields and can play an important role in promoting a transition process towards sustainable agriculture. Graphical Abstract

Número Completo (Mayo-junio)

“…El tercer clúster se destaca por el estudio de los suelos, agricultura de suelo, calibración, carbón, propiedad de suelo, contaminación de suelo, asuntos de suelos orgánicos etc. que lo relacionan además con su impacto económico (Biney et al, 2022;Pesqualoto et al, 2022;Magallanes-Quintanar et al, 2022;Maino et al, 2022).…”

Novel Nanomaterials Made of Humic Substances from Green Composts and Chitosan Exerting Antibacterial Activity

“…In the case of agricultural residues, their mass dimension is relevant because, in Europe alone, they account for 1000 million tonnes per year and represent about 40% of the total wastes produced on the continent . Composting such residues or exploiting them as soil conditioners are efficient ways to recycle agricultural residues and usefully improve the agroecosystem quality. , Compost is produced by microbially transforming biomasses under aerobic conditions, and it is commonly employed to restore the chemical, physical, and biological properties of soils. , Moreover, compost is a valuable source of humic substances (HS), which are reckoned to exert a direct positive stimulation of plant growth. , HS extracted from the compost are found to stimulate the emergence of lateral roots in plants, thus allowing a more extensive exploration of soil volumes , and an increased nutrient uptake. − …”

Humic Substances Isolated from Recycled Biomass Trigger Jasmonic Acid Biosynthesis and Signalling

“…The lack of sustainability is amplified by the worsening of adverse cropping conditions, the jeopardizing of food security driven by climate change (soil drought and salinity), and the lowering efficacy and affordability of external inputs (chemical fertilizers, GMO seeds, pesticides, etc.). In this scenario, a widening interest has been devoted to the deployment of more accessible and eco-sustainable technologies based on the application of plant biostimulants (PBs) [2]. PBs are defined as substances and microorganisms, either distinct or combined, that are applied in small amounts, whose function is to stimulate and steer biochemical reactions and physiological activities, purposed to enhance uptake and nutrient use efficiency and improve tolerance to biotic and abiotic stresses while preserving or increasing crop yield and quality [3].…”