Carbonate influences on the biogeochemical processes driving the stabilization of soil organic carbon in drylands

碳酸盐对驱动旱地土壤有机碳稳定的生物地球化学过程的影响

基本信息

批准号：
EP/X022498/1
负责人：
Kirsten Ball
金额：
$ 32.5万
依托单位：
University of Aberdeen
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2023
资助国家：
英国
起止时间：
2023 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FX022498%2F1
关键词：
Carbonate influences biogeochemical processes driving

项目摘要

Increasing temperatures and worsening drought from climate change are exacerbating soil degradation and desertification indrylands, presenting a major threat to food security. Soil organic carbon (SOC) loss is a strong driver of soil degradation anddesertification. Increasing SOC can mitigate soil degradation, but dryland SOC stocks can be minimal, and critically, most soil carbonin drylands exists as carbonate (SIC). SIC likely moderates the physical stabilization of SOC in the soil mineral matrix via pedogenicprocesses that form SIC-organo-mineral structures. Pedogenic processes may increase SOC stabilization by controlling physical accessof microorganisms to substrate, but it's unclear how they indirectly alter microbial processes and SOC decomposition/stabilization. Tothis end, SIC-SOC-STABLE aims to 1) quantify the global influence of SIC on SOC stabilization in drylands using an established dataset,and 2) validate global patterns along a local field gradient and to generate a detailed understanding of how physical stabilizationstructures, driven by carbonate pedogenesis influence the microbial processes driving SOC stabilization. Further, considering theimpacts of soil management on SOC storage in drylands is fundamental given that soil tillage may accelerate carbonate pedogenesis.It addresses the agricultural implications of IPCC recommended management practices like reduced tillage on SOC stabilization incalcareous soils, by 3) experimentally quantifying the influence of soil disturbance on carbonate pedogenesis and the fate ofmicrobially-mediated SOC storage. Finally, because reduced tillage requires greater mechanical weeding, a role which predominantlyfalls on women in rural drylands, the proposed MSCA considers gender disparity in labor when advocating best practices to increasesoil carbon. To achieve this, it 4) develops a scientifically robust training and support tool to empower and equip women for key rolesin agricultural management.

气候变化导致气温升高和干旱加剧，加剧了旱地土壤退化和荒漠化，对粮食安全构成重大威胁。土壤有机碳（SOC）损失是土壤退化和荒漠化的重要驱动因素。增加 SOC 可以缓解土壤退化，但旱地 SOC 储量可能很少，而且最重要的是，旱地的大多数土壤碳以碳酸盐 (SIC) 形式存在。 SIC 可能通过形成 SIC-有机矿物结构的成土过程调节土壤矿物基质中 SOC 的物理稳定性。成土过程可能通过控制微生物对基质的物理访问来增加 SOC 稳定性，但尚不清楚它们如何间接改变微生物过程和 SOC 分解/稳定。为此，SIC-SOC-STABLE 旨在 1) 使用已建立的数据集量化 SIC 对旱地 SOC 稳定的全球影响，2) 验证沿局部场梯度的全球模式，并详细了解物理稳定结构如何、由碳酸盐成土作用驱动的微生物过程会影响驱动 SOC 稳定的微生物过程。此外，鉴于土壤耕作可能加速碳酸盐成土作用，考虑土壤管理对旱地 SOC 存储的影响至关重要。它解决了 IPCC 建议的管理实践的农业影响，例如减少耕作对钙质土壤 SOC 稳定性的影响，通过 3）实验量化土壤扰动对碳酸盐成土作用和微生物介导的 SOC 储存的命运。最后，由于减少耕作需要更多的机械除草，而这一作用主要落在农村旱地的妇女身上，因此拟议的 MSCA 在倡导增加土壤碳的最佳做法时考虑了劳动力中的性别差异。为了实现这一目标，它 4) 开发了科学可靠的培训和支持工具，以赋予妇女权力并让妇女具备在农业管理中发挥关键作用的能力。