Improvements of soil organic carbon and reduction of carbon footprint are critical for the sustainability of agricultural production system. In a 14-year (2006–2020) field experiment, we assessed the effects of conservational (reduced/zero) tillage and residue management (incorporation/retention) (CsT+RM) practices on carbon input, carbon sequestration, productivity and profitability rice-wheat system (RWS) in western Indo-Gangetic Plains (IGP) of India. Experiment consisted one scenario of conventional tillage (Sc-1: Puddle transplanted rice - conventional tilled wheat); and four scenarios of CsT+RM that are, Sc-2: Reduce tilled direct seeded rice (RTDSR) - reduce tilled wheat (RTW); Sc-3: RTDSR-RTW + 1/3rd residue incorporation (RI); Sc-4: Zero tilled direct seeded rice (ZTDST)-zero tilled wheat (ZTW); and Sc-5: ZTDSR-ZTW + 1/3rd residue retention (RR). Overall, 14-years mean DSR yield significantly (p < 0.05) lowered (9.0–22.0 %), and wheat yield significantly increased (4.4–9.2 %) in CsT+RM practices as compared to Sc-1. The mean RWS yield lowered by 1.0–3.8 % in reduced tillage and 6.3–9.3 % in zero tillage, along with 10.9–17.4 % lower cost of cultivation and nonsignificant higher return over variable cost under CsT+RM practices. The sustainable yield index of DSR was lower (0.50–0.58), and wheat was higher (SYI; 0.65–0.69) in indicating the low sustainability of DSR and better sustainability of wheat in CsT+RM. The long-term CsT+RM caused net enrichment in SOC stock by 2.4–21.0 %, and carbon sequestration from 9.9 % to 87.0 % in different scenarios over Sc-1. In order to counterbalance the loss of SOC and maintain its level, a critical amount of 1.17 Mg C ha−1 yr−1 need to be added into the soil. The CsT+RM thus enhanced the SOC stock and sequestration in the soil and provided at par system yield in reduced tillage and lower yield in zero tillage grown RWS. Further, better management of DSR including development of suitable genotype for direct seeding, ensuring uniform crop establishment, weed and micronutrient management under reduced/zero tillage is needed for long-term sustainability of DSR-ZTW system in the western IGP of India.

中文翻译：

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14 年作物种植、耕作和残留物管理对碳输入、土壤碳封存、作物生产力和水稻-小麦系统盈利能力的影响


土壤有机碳的改良和碳足迹的减少对于农业生产系统的可持续性至关重要。在一项为期 14 年（2006-2020 年）的田间实验中，我们评估了保护性（减少/零）耕作和残留物管理（掺入/保留）（CsT+RM）做法对印度西部恒河平原 （IGP） 的碳输入、碳封存、生产力和盈利能力稻麦系统 （RWS） 的影响。实验包括一种常规耕作场景（Sc-1：水坑移栽稻 - 常规耕作小麦）;以及 CsT+RM 的四种情景，即 Sc-2：减少耕作直接播种稻 （RTDSR） - 减少耕作小麦 （RTW）;Sc-3： RTDSR-RTW + 1/3 残基掺入 （RI）;Sc-4： 零耕直播稻 （ZTDST）-零耕小麦 （ZTW）;和 Sc-5：ZTDSR-ZTW + 1/3 残基保留 （RR）。总体而言，与 Sc-1 相比，CsT+RM 实践中的 14 年平均 DSR 产量显着降低 （p < 0.05） （9.0-22.0 %），小麦产量显著增加 （4.4-9.2 %）。减少耕作的平均 RWS 产量降低了 1.0-3.8%，零耕降低了 6.3-9.3%，同时在 CsT+RM 实践下，种植成本降低了 10.9-17.4%，与可变成本相比，回报率没有显着提高。DSR 的可持续产量指数较低 （0.50–0.58），小麦较高 （SYI;0.65–0.69），表明 DSR 的可持续性较低，而 CsT+RM 中小麦的可持续性较好。长期 CsT+RM 导致 SOC 储量净富集 2.4–21.0 %，在 Sc-1 的不同情景下碳封存率从 9.9 % 增加到 87.0 %。为了抵消 SOC 的损失并保持其水平，需要在土壤中添加 1.17 Mg C ha-1 yr-1 的临界量。 因此，CsT+RM 增强了土壤中的 SOC 储量和封存能力，并在少耕中以面值系统产量提供，在免耕种植的 RWS 中提供较低的产量。此外，为了印度西部 IGP 的 DSR-ZTW 系统的长期可持续性，需要更好地管理 DSR，包括开发合适的直接播种基因型、确保均匀的作物生长、在减少/零耕作下进行杂草和微量营养素管理。