Balancing Productivity, Grain Quality and Carbon Footprint in Malting Barley Through Soil Tillage Systems Under Mediterranean Conditions

Soil tillage significantly affects yield, grain quality, and the environmental footprint of cereals under Mediterranean rainfed conditions. This two-year field study evaluated five contrasting tillage systems: conventional tillage (CT), disc harrow (DH), chisel plough (CP), and two no-tillage systems, including long-term (NT1, 30 years) and recently established (NT2, 3–4 years), for their effects on yield and quality traits, and greenhouse gas (GHG) emissions of malting barley grown in Central Greece. Conventional tillage achieved the highest aboveground biomass (up to 12.1 t ha−1) and yield (up to 6.3 t ha−1), but resulted in lower thousand-grain weight (TGW) and reduced grain plumpness. In contrast, no-tillage systems produced slightly lower yields (4.3–5.2 t ha−1), significantly higher TGW (up to 58.3 g), and improved grain-size distribution, while maintaining grain protein concentration within acceptable malting thresholds (10.4–11.0%). Environmental assessment indicated substantially lower GHG emissions under no-tillage, with NT2 achieving the lowest carbon footprint (0.19–0.22 kg CO2 eq kg−1). Carbon footprint estimates revealed that carbon accounting tools prioritize short-term management transitions over long-term no-tillage systems. Year effects reflected differences in rainfall distribution and temperature during critical growth stages. Overall, no-tillage systems provided the most balanced agronomic, qualitative, and environmental performance for malting barley under Mediterranean conditions.