Effect of the forage maize-pasture rotation on the soil carbon storage in Galicia (NW Spain)

Galicia is a region in NW Spain with high economic dependence on dairy cattle where livestock feeding is mainly based on the production of forage maize. In this region, one of the major challenges for the forage maize production systems is to maximize the economic return while minimizing environmental pollution mainly associated with greenhouse gas emissions such as CO2. In this context, crop rotations influence not only crop growth, but also the soil chemical properties such as the amount of carbon storage in the soil. This study aimed to evaluate the effect of the forage maize-pasture rotation on the carbon storage in the whole soil and each soil aggregate fraction (250–2000 μm; 53–250 μm and < 53 μm) under different climatic conditions in Galicia. In September 2020, a total of sixteen plots were selected in the interior and coastal areas of Galicia. In each area, four plots with a forage maize-pasture rotation and four plots without rotation with pasture were selected to collect composite soil samples. In the laboratory, the total soil carbon and the carbon storage in the different soil fractions were estimated. In this study, the crop rotation increased the amount of carbon storage in the soil in the long term.