SOIL CARBON DYNAMICS AND CROP RESPONSE IN BARLEY AND CHICKPEA GROWN UNDER CARBON-FARMING AND CONVENTIONAL PRACTICES: A REGIONAL ASSESSMENT IN NORTH MACEDONIA

Abstract

Soil organic carbon (SOC) represents a key indicator of soil health, fertility, and the capacity of agroecosystems to contribute to climate change mitigation through carbon sequestration. Within the framework of the CARBONICA project, this study evaluates SOC dynamics in barley (Hordeum vulgare L.) and chickpea (Cicer arietinum L.) cultivated under contrasting management systems, carbon farming (CF) and conventional practices, across representative pilot sites in North Macedonia. Soil sampling was conducted from the 0-20 cm layer using a stratified composite approach that accounted for crop type and management regime. Soil organic carbon (SOC) content was determined using the validated Walkley–Black method, focusing on the biologically active organic carbon fraction, while total nitrogen (TN) was quantified using the Kjeldahl method. Experimental setups included four treatment variants: chickpea under CF (B2) and conventional management (B3), and barley under conventional (B4) and CF practices (B5). The results revealed distinct temporal and management-dependent patterns in SOC dynamics. In barley systems, SOC declined during the monitoring period under conventional management, decreasing from 1.34% at the start-point to 0.89% at the end-point. In contrast, carbon-farming practices promoted a substantial increase in SOC, from 1.25% to 1.68%, indicating enhanced carbon sequestration potential. Similar trends were observed in chickpea systems, where SOC under CF increased from 1.18% to 1.57%, while conventional management resulted in a decline from 1.22% to 0.91%. Total nitrogen exhibited distinct crop- and management-dependent dynamics. In barley, TN decreased from 1.27 to 1.01 mg g⁻¹ under conventional management but increased from 1.28 to 1.36 mg g⁻¹ under carbon-farming practices. In contrast, chickpea showed progressive nitrogen enrichment throughout the growing season, reaching 1.41 and 1.45 mg g⁻¹ under conventional and carbon-farming management, respectively. The study provides region-specific evidence supporting the implementation of regenerative agricultural practices for improving soil quality, increasing carbon storage, and promoting sustainable land management in North Macedonia.