Soil Respiration in Maize, Wheat, and Barley Across a Growing Season: Findings from Croatia’s Continental Region

Soil respiration (Rs) in croplands is of primary importance in understanding the carbon (C) cycle mechanism and C balance of agroecosystems. This study examines the seasonal Rs dynamics in three predominant cereal crops, maize, wheat, and barley, in continental Croatia during the growing season 2021/2022. This study was conducted at the Agricultural Institute Osijek, featuring a continental climate and silty clay soil. Rs was measured monthly throughout the growing season by following an in situ closed static chamber method and using Infrared Gas Analyzers (IRGAs) with three replicates for each crop and a fallow control. This study found that crop type plays a prominent role in Rs dynamics, while temperature and moisture can have modifying effects. Significant (p < 0.05) temporal variation in Rs between months was found in wheat, barley, and maize. Mean seasonal Rs values for wheat, barley, and maize were, respectively, 14.73, 19.64, and 12.72 kg CO2-C ha−1 day−1. Cropped fields demonstrated two to three times higher Rs than no vegetation/fallow and indicated the significance of autotrophic respiration in cropped fields. There exists a seasonal dynamics of Rs governed by the complex interaction of biotic and abiotic factors that influences Rs. This necessitates a multifaceted examination for effective understanding of seasonal Rs dynamics and its integration to modeling studies.