Bio

My main interests lie within anthropogenic climate change, environmental science, and agriculture. The complex system dynamics and interconnections between agriculture and the environment including nutrient cycling, energy use, and greenhouse gas emissions are a few of the most critical challenges for today's soil scientists. After completing a master’s degree in Sustainability Science and Environmental Studies at Lund University in Sweden, researching farmer adoption of practices which mitigate GHGs from arable soils in the Netherlands at Wageningen University, I started a PhD in Earth System Science at Stanford University, aiming to focus on soil and environmental biogeochemistry. In parallel to my work in academia, I have been working on a start-up to address food waste and food insecurity in CA (Ugly Food Market), in addition to being a team member on several projects including a sharing library (Circle Centre), a soil science educational platform (Soil Life), and other sustainability related initiatives.

Honors & Awards

  • Fellowship Recipient, EDGE, Enhancing Diversity in Graduate Education Doctoral Program (2020)

Contact

  • Academic
    amgomes@stanford.edu
    University - Student Department: Department of Earth System Science Position: Graduate

Additional Info

Links

All Publications

  • Nitrogen mineralization of cover crop residue depends on carbon-to-nitrogen ratio and soil temperature. Journal of environmental quality Gomes, A., Gutierrez, D., Castaneda, S., Brennan, E., Smith, R., Fendorf, S. 2026; 55 (1): e70107

    Abstract

    Groundwater nitrate contamination is largely attributed to fertilizer and intensive livestock manure inputs in agricultural systems. California's Salinas Valley is an area where regional policy is aimed at reducing nitrate leaching. Nonlegume winter cover crops can help decrease nitrate leaching by scavenging residual soil nitrogen (N) during winter fallow periods following the cropping season. However, the ability of fall-incorporated cover crops to decrease nitrate leaching and recycle N to subsequent cash crops is unknown. We conducted a 112-day laboratory soil incubation experiment using Merced rye (Secale cereale) cover crop shoot biomass, with four carbon-to-nitrogen (C/N) ratios (10, 14, 19, and 30), at three temperatures (10°C, 15°C, and 20°C). Destructive soil sampling was done at six intervals during the incubation to measure plant-available nitrogen. Rye biomass with the lowest C/N ratio (10) had the highest average nitrogen mineralization (Nmin) rate (56%) at the warmest temperature (20°C). Conversely, biomass with the highest C/N (30) showed net nitrogen immobilization at 10°C and 15°C during the incubation, transitioning to net mineralization only at 20°C. We found a linear correlation between soil temperature and nitrogen mineralization (at Day 112) for higher C/N ratios. Furthermore, doubling the soil mineral nitrogen content had a negligible impact on the percent mineralization of the C/N 30 residue. These results provide useful information to help farmers and policymakers understand mineralization dynamics from fall-, winter-, or spring-terminated cereal cover crops.

    View details for DOI 10.1002/jeq2.70107

    View details for PubMedID 41367217

  • Soil carbon concentration drives anoxic microsites across horizons, textures, and aggregate position in a California grassland GEODERMA Lacroix, E. M., Gomes, A., Honeyman, A. S., Huy, K. R., Fendorf, S., Noel, V., Aeppli, M. 2025; 454

    View details for DOI 10.1016/j.geoderma.2025.117165

    View details for Web of Science ID 001414372300001

  • Microbial Proxies for Anoxic Microsites Vary with Management and Partially Explain Soil Carbon Concentration. Environmental science & technology Lacroix, E. M., Gomes, A., Heitmann, G. B., Schuler, D., Dekas, A. E., Liptzin, D., Aberle, E., Watts, D. B., Nelson, K. A., Culman, S., Fendorf, S. 2024

    Abstract

    Anoxic microsites are potentially important but unresolved contributors to soil organic carbon (C) storage. How anoxic microsites vary with soil management and the degree to which anoxic microsites contribute to soil C stabilization remain unknown. Sampling from four long-term agricultural experiments in the central United States, we examined how anoxic microsites varied with management (e.g., cultivation, tillage, and manure amendments) and whether anoxic microsites determine soil C concentration in surface (0-15 cm) soils. We used a novel approach to track anaerobe habitat space and, hence, anoxic microsites using DNA copies of anaerobic functional genes over a confined volume of soil. No-till practices inconsistently increased anoxic microsite extent compared to conventionally tilled soils, and within one site organic matter amendments increased anaerobe abundance in no-till soils. Across all long-term tillage trials, uncultivated soils had ∼2-4 times more copies of anaerobic functional genes than their cropland counterparts. Finally, anaerobe abundance was positively correlated to soil C concentration. Even when accounting for other soil C protection mechanisms, anaerobe abundance, our proxy for anoxic microsites, explained 41% of the variance and 5% of the unique variance in soil C concentration in cropland soils, making anoxic microsites the strongest management-responsive predictor of soil C concentration. Our results suggest that careful management of anoxic microsites may be a promising strategy to increase soil C storage within agricultural soils.

    View details for DOI 10.1021/acs.est.4c01882

    View details for PubMedID 38875507

  • Long-term reduced tillage and winter cover crops can improve soil quality without moisture CALIFORNIA AGRICULTURE Gomes, A., DeVincentis, A. J., Solis, S., Zaccaria, D., Munk, D., Bali, K., Shrestha, A., Gould, K., Mitchell, J. 2023; 77 (1): 4-14

    View details for DOI 10.3733/ca.2023a0001

    View details for Web of Science ID 001024897600001

  • Contributions of anoxic microsites to soil carbon protection across soil textures GEODERMA Lacroix, E. M., Mendillo, J., Gomes, A., Dekas, A., Fendorf, S. 2022; 425

    View details for DOI 10.1016/j.geoderma.2022.116050

    View details for Web of Science ID 000847217000011

  • Impacts of winter cover cropping on soil moisture and evapotranspiration in California's specialty crop fields may be minimal during winter months Results from a 3-year study suggest that processing tomato and almond growers can adopt winter cover cropping without changing irrigation practices CALIFORNIA AGRICULTURE DeVincentis, A., Solis, S., Rice, S., Zaccaria, D., Snyder, R., Maskey, M., Gomes, A., Gaudin, A., Mitchell, J. 2022; 76 (1): 37-45

    View details for DOI 10.3733/ca.2022a0001

    View details for Web of Science ID 000795862200010

  • Time to Transition: Barriers and Opportunities to Farmer Adoption of Soil GHG Mitigation Practices in Dutch Agriculture FRONTIERS IN SUSTAINABLE FOOD SYSTEMS Gomes, A., Reidsma, P. 2021; 5

    View details for DOI 10.3389/fsufs.2021.706113

    View details for Web of Science ID 000706454300001

https://orcid.org/0000-0001-7526-3639