Pirinç-Kuru Tarım Ürün Rotasyonları, Kararlı Organik Karbon Modülasyonu Yoluyla Farklı Sera Gazı Emisyonlarını ve Ürün Verimini Etkiler

Özet (abstract)

Context Optimizing crop rotations is essential for synergistically increasing yield and reducing environmental impacts. However, in rice-dryland crop rotation systems, the underlying mechanisms through which different dry-season crops influence subsequent rice yield and greenhouse gas (GHG) emissions remain to be elucidated. Objective This study aims to clarify the mechanisms by which dry-season crops influence the productivity and GHG emissions of the subsequent rice season, to identify agronomic strategies that balance grain yield and environmental effects. Methods Over three consecutive years (2021–2023), a field experiment was conducted to assess how different dry-season crops affected soil properties, rice productivity, and GHG emissions in the subsequent rice season. Results Four rotation treatments were compared: fallow-rice rotation (FR), wheat-rice rotation (W R ), garlic-rice rotation (GR), and rapeseed-rice rotation (RR). Compared with the FR system, all rice-dryland crop rotation treatments enhanced rice yield by 10.74%–16.97% but also elevated global warming potential (GWP) by 13.96%–35.88%. Among the three rice-dryland crop rotation treatments, W R system exhibited the lowest rice yield (11.00 Mg ha⁻¹), GWP (3247.11 kg CO 2 -eq ha −1 ), and greenhouse gas intensity (GHGI, 0.29 kg CO 2 -eq kg −1 ). In contrast, the GR treatment achieved the highest rice yield (11.80 Mg ha −1 ), GWP (4009.53 kg CO 2 -eq ha −1 ), and GHGI (0.34 kg CO 2 -eq kg −1 ). The RR treatment showed intermediate values, with a yield of 11.77Mg ha −1 , GWP of 3722.73 kg CO 2 -eq ha −1 , and GHGI of 0.32. Methane (CH 4 ) was the predominant GHG, accounting for 95.80% of total GWP. Conclusions The increased labile organic carbon (LOC) in topsoil under GR and RR treatments stimulated methanogenic activity by providing abundant substrates, thereby significantly enhancing CH 4 emissions. In contrast, the W R treatment maintained significantly lower levels of labile organic carbon, effectively suppressing CH 4 emissions. Moreover, the higher nutrient content and organic matter in GR and RR treatments enhanced rice productivity. Implications These findings elucidate the underlying mechanisms through which different dry-season crops modulate soil organic carbon fractions, thereby influencing subsequent rice yield and GHG emissions. Specifically, the W R treatment effectively reduced GHG emissions but at the expense of yield, underscoring a trade-off between environmental sustainability and agricultural productivity.

Yazarların özeti; kaynağından alınmıştır. Field Crops Research, 2026 · DOI ↗