RUI: CAS-Climate: Carbon sequestration through enhanced weathering in agricultural soils with co-benefits to soil quality and crop yield

为了实现限制未来变暖的国际目标，几十亿吨级的二氧化碳清除将是必要的。增强风化是一种令人兴奋的二氧化碳去除技术，可以利用现有的基础设施应用于农业，同时通过改善土壤质量和作物产量为农民提供额外的好处。取代农业中使用的更传统的材料(如用于石灰处理的碳酸盐岩石)，富含钙和镁的硅酸盐岩石(如玄武岩)具有吸引力，因为它们的溶解消耗二氧化碳，并最终将碳以碱度存储在海洋中。通过增加可供风化的矿物表面积，铺展粉碎的硅酸盐岩石可以增加风化(和除碳)的速度。然而，评估增强风化的现场试验很少，实现的碳去除速率和协同效益也鲜为人知。该奖项支持的研究将进行为期三年的田间试验，测试每年使用粉碎硅酸盐矿物对作物和土壤的碳去除效率和协同效益。调查人员将通过与明尼苏达州东南部的当地农业合作伙伴合作，监督一项为期三年的田间试验。增强风化的试验性处理包括局部产生的破碎玄武岩和硅酸盐工业废物(矿渣)。该项目将优先通过测量土壤水的碱度、土壤的总碳含量(有机碳和无机碳)和土壤呼吸速率来直接跟踪碳封存。对土壤有机碳和土壤微生物群落的仔细监测将有助于确定粉碎的硅酸盐对土壤微生物群和土壤碳的有机成分的影响，这两者都是许多保护性农业努力的主要重点。这项研究的所有阶段都将在卡尔顿学院的本科生中进行。这项工作的结果将为加强气候变化提供重要的现实约束，并将与科学界和农业界广泛分享。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Carbon dioxide removal at the gigaton scale will be necessary to meet international goals for limiting future warming. Enhanced weathering is an exciting carbon dioxide removal technology that could be applied in agriculture using existing infrastructure while providing added benefits to farmers through improved soil quality and crop yields. In place of more traditional materials used in agriculture (like carbonate rocks used for liming), silicate rocks rich in Ca and Mg (e.g., basalts) are attractive because their dissolution consumes carbon dioxide and ultimately stores that carbon as alkalinity in the oceans. Spreading crushed silicate rocks increases the rate of weathering (and carbon removal) by increasing the available mineral surface area for weathering. However, field experiments evaluating enhanced weathering are rare and realized rates of carbon removal and co-benefits are poorly understood. This award supports research that will conduct a three-year field trial testing the carbon removal efficiency and co-benefits to crops and soils of annual applications of crushed silicate minerals. The investigator will monitor a three-year field trial through collaboration with local farming partners in southeastern Minnesota. Experimental treatments of enhanced weathering include a locally occurring crushed basalt and a silicate industrial waste product (slag). The project will prioritize direct tracking of carbon sequestration through measurements of alkalinity in soil water, total carbon content of soils (both organic and inorganic carbon), and soil respiration rates. Careful monitoring of soil organic carbon and microbial communities in the soil will help to determine the impacts that crushed silicates have on the soil microbiome and the organic component of soil carbon, both of which are the main focus of many efforts in conservation agriculture. All phases of this research will be conducted with undergraduate students from Carleton College. Results from this work will provide important real-world constraints on enhanced weathering and will be shared broadly with both the scientific and agricultural communities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.