Interaction Between Conservation Tillage and Nitrogen Fertilization Shapes Prokaryotic and Fungal Diversity at Different Soil Depths: Evidence From a 23-Year Field Experiment in the Mediterranean Area

Abstract

Soil biodiversity accomplishes key roles in agro-ecosystem services consisting in preserving and enhancing soil fertility and nutrient cycling, crop productivity and environmental protection. Thus, the improvement of knowledge on the effect of conservation practices, related to tillage and N fertilization, on soil microbial communities is critical to better understand the role and function of microorganisms in regulating agro-ecosystems. In the Mediterranean area, vulnerable to climate change and suffering for management-induced losses of soil fertility, the impact of conservation practices on soil microbial communities is of special interest for building mitigation and adaptation strategies to climate change. A long-term experiment, originally designed to investigate the effect of tillage and N fertilization on crop yield and soil organic carbon, was utilized to understand the effect of these management practices on soil prokaryotic and fungal community diversity. The majority of prokaryotic and fungal taxa were common to all treatments at both soil depths, whereas few bacterial taxa (Cloacimonates, Spirochaetia and Berkelbacteria) and a larger number of fungal taxa (i.e., Coniphoraceae, Debaryomycetaceae, Geastraceae, Cordicypitaceae and Steccherinaceae) were unique to specific management practices. Soil prokaryotic and fungal structure was heavily influenced by the interaction of tillage and N fertilization: the prokaryotic community structure of the fertilized conventional tillage system was remarkably different respect to the unfertilized conservation and conventional systems in the surface layer. In addition, the effect of N fertilization in shaping the fungal community structure of the surface layer was higher under conservation tillage systems than under conventional tillage systems. Soil microbial community was shaped by soil depth irrespective of the effect of plowing and N addition. Finally, chemical and enzymatic parameters of soil and crop yields were significantly related to fungal community structure along the soil profile. The findings of this study gave new insights on the identification of management practices supporting and suppressing beneficial and detrimental taxa, respectively. This highlights the importance of managing soil microbial diversity through agro-ecological intensified systems in the Mediterranean area.

Crop Management Impacts the Soybean (Glycine max) Microbiome

“…Similar to Fungi, when the organic management system was not included in analyses, there was still a significant difference between conventional and no-till management systems, although the difference was smaller than in fungal communities ( Supplementary Table S4B and Supplementary Figure S7). As with Fungi, this distinction between conventional and no-till agriculture has been demonstrated in soils, but has been understudied within plant compartments (Piazza et al, 2019). Additionally, in the leaves the effect of management regime was reduced throughout the growing season when analyzing no-till and conventionally managed treatments alone (Supplementary Figure S7G and Supplementary Table S4B).…”

Field Inoculation of Bread Wheat with Rhizophagus irregularis under Organic Farming: Variability in Growth Response and Nutritional Uptake of Eleven Old Genotypes and A Modern Variety

“…The approach of analyzing the AMF community structure within roots is confirmed as insightful and robust for revealing fungal-plant genotypes compatibility [89,90]. This approach was proved successful for AMF and other microbes in bulk and rhispheric soil [91][92][93][94][95].…”

Spectroscopic and Foliar pH Model for Yield Prediction in a Symbiotic Corn Production

“…The results reported in this study encourage further implementation of the basic symbiotic model for maize production a basic crop that is currently threatened by high costs of production. In our opinion, this minor research route for smart agriculture could lead to an advancement in parallel knowledge concerning the hard microbiomic horizon 37,38 . In this context, the most interesting result has been to confirm the validity of the rapid analyses of foliar pH as an effective way of phenotyping AM symbiosis, and the litter-bag probes as a means of signaling the local hospitality of a soil to biota inoculations.…”