Implication of soil carbon changes on the greenhouse gas emissions of pickled ginger: a case study of crop rotation cultivation in Northern Thailand

As the global demand for ginger products continues to increase due to its medicinal and culinary properties, concerns arise regarding the loss of soil carbon (C) caused by agricultural management practices. It is crucial to understand the impact of these practices on soil C changes, especially in ginger rotation cropping systems. The goal of this study was to estimate the soil C changes resulting from management practices of ginger rotation cropping systems, and understand their influence on greenhouse gas (GHG) emissions of pickled ginger. The Intergovernmental Panel on Climate Change (IPCC) Tier 1 method with modification was used to predict the soil C changes of two different 4-year rotation cycles, one of maize-ginger rotation relative to the reference of maize-pumpkin rotation, and the other of upland rice-ginger rotation relative to the reference of upland rice-vegetable rotation for 20 years of cultivation. From the results, ginger rotation cropping systems could lead to soil C changes, ranging from - 0.02 to 0.31 Mg C ha(-1) yr(-1), compared to - 2.02 Mg C ha(-1) yr(-1) when converting forests to ginger plantations. Consequently, the net GHG emissions of pickled ginger varied from - 6.71% to 0.00% for ginger rotations and 46.33% for converting forest to cultivate ginger. The waste disposal was the primary source of GHG emissions of pickled ginger. Sustainable waste management practices could potentially reduce GHG emissions by over 60%. Implementing certain practices, such as reduced tillage, keeping all crop residue on the field, and avoiding deforestation to ginger plantations, could increase soil C sequestration.