Work

Exploring soil genes as proxies for short-term SOC and N dynamics: Insights from a four-year on-farm experimentation

Year: 2025

Type: article

Abstract: The sustainability of different management practices to enhance soil organic carbon (SOC) sequestration and reduce nitrogen (N) losses remains debated due to site-specific variability. Investigating soil physicochemical and biological factors is crucial, and soil functional genes can serve as key indicators of nutrients cycling and soil health. The present 4-year on-farm experiment in northeastern Italy, developed in collaboration with local farmers and a land reclamation authority, investigated the effects of two organic fertilizers (compost or digestate), a triticale ( X triticosecale ) cover crop treatment (CC) under rainfed vs. irrigated conditions on SOC, total N (nitrates - NO 3 - and Total Kjeldahl Nitrogen -TKN), and soil N and C functional genes in a biennial maize-soybean rotation. Compost application led to higher short-term SOC accumulation and greater GH48 cellulolytic enzyme activity than digestate supposedly due to its more recalcitrant molecules. In compost treatments, higher SOC levels enhanced microbial denitrification ( nosZ ). While triticale CC did not impact SOC, it reduced soil NO 3 - content. Digestate exhibited greater competition with microbial N fixation (lower nifH gene copies) than compost. Elevated NO 3 - levels in the soil stimulated nitrification activity (AOA) across all management practices. A general increase in N, SOC, and microbial-mediated activities throughout the four experimental years suggested an overall enhancement of soil biological fertility. Agronomic management strategies influenced N and SOC dynamics, and functional genes linked to C and N cycling showing their potential as proxies for tracking these changes. However, while gene abundance was sensitive to management practices, environmental conditions also influenced the results, making it challenging to isolate single key factors.

Source: Italian Journal of Agronomy

DOI: 10.1016/j.ijagro.2025.100039

Authors: Giorgia Raimondi, Carmelo Maucieri, Laura Maretto, Piergiorgio Stevanato, Andrea Squartini, Maurizio Borin

Institution: University of Padua

Language: English

Topic: Soil Carbon and Nitrogen Dynamics

Subfield: Soil Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDGs: Zero hunger, Life on land, Climate action

Open Access status: gold

Estimated APC paid: $1,640