Brief Summary of Minutes of Annual Meeting

Accomplishments (Short Term Outputs):

 Florida:

• Cultivating flooded rice in the summer as a rotation crop has been shown to reduce phosphorus loads in farm canals and also to improve soil quality. We have been successful in taking our research and findings beyond peer-reviewed publications and reporting.
• The adoption of cover crops such as sunn hemp and cow peas during summer (fallow period) in south Florida has shown to increase soil organic matter and maximum water holding capacity.
• The application of organic amendments such as bagasse as a soil amendment is proving to be a good practice for local growers planting sugarcane, particularly on sandy mineral soils with very low organic matter (<2%).

 Michigan:

• Climate-smart practice interactions: In a no-till soybean system, biochar (10 Mg ha-1) and/or cereal rye cover crops increased SOC by 12-50% relative to conventional tillage in the first year; cereal rye had the largest SOC gains (30-42% higher than other CSA treatments).
• Biochar alone or with cereal rye strongly increased extracellular enzyme activities supporting C and N cycling (e.g., beta-glucosidase +108% to +131%; N-acetylglucosaminidase +58.8% to +184% vs. conventional tillage) and altered microbial biomass indicators (PLFA), with SOC positively related to microbial biomass.
• Interannual dynamics: SOC declined ~13% in the second year across treatments; biochar plus cereal rye appeared to dampen SOC losses, suggesting potential mitigation of biochar-induced priming when combined with cover crops and no-till management.
• Microstructure controls on microbial CUE: Using selective delivery of isotopically labeled substrates to pore-size fractions (<30, 30-150, >150 μm), microbial CUE was highest in small pores under N limitation; N addition eliminated pore-size differences and reduced CUE in small pores, indicating that nutrient context and microhabitat jointly shape microbial allocation to growth vs. respiration.
• pH-mineralogy controls on MAOM: Artificial soil experiments showed pH alters the chemical composition of newly formed MAOM through changes in microbial activity/CUE and necromass composition; pH also influenced necromass retention and interacted with mineralogy to determine MAOM thermal stability. Increasing necromass loading weakened organo-mineral bonding and reduced MAOM stability.
• Diazotroph biodiversity and FLNF: In the field, FLNF was better predicted by soil moisture and temperature than diazotroph diversity; experimentally reducing biodiversity decreased FLNF and strengthened diversity-function relationships, with land management mediating whether diversity or microbial biomass best predicted FLNF.

 Minnesota:

• Deeper SOC concentrations were more correlated with yield and with profitability than topsoil SOC.
• Short term SOM incubations were more sensitive to in-field temperatures than expected where mean annual temperature correlated highly with C mineralization (Objective 1a and 1c).
• No discernible trend was seen in soil biological indicators in cropping systems varying in tillage and crop rotation over more than a decade.
• A life cycle analysis was performed to quantify the magnitude and variance of emissions reduction and soil carbon gains of perennial grain production, and found that even conservative estimates show some soil carbon gain, and neutral emissions, after multiple years of perennial grain production (Objective 1a).

 North Dakota:

• Routine processing of soils of the Prairie Pothole Region for carbon analysis may result in loss of total C and inorganic C which may impact soil C analysis. Carbonate concretions and nodules were removed prior to soil crushing and then analyzed separately before summarizing soil total C (TC), inorganic C (IC) and organic C (OC) showing that materials that are often screened out during the soil crushing process can influence the analysis of C in a soil profile. The carbonate fragments added as much as 3.9 kg C/m²/depth to the IC pool while as much as 0.25 kg C/m²/depth could be added to the OC pool due to OC being contained in the carbonate fragments. This may require modifying procedures where C stocks are being quantified below an 0.3 m depth and where carbonates occur in the soil profile
• Resampling paired soil sites on similar soils over 30 years shows that acidification of cropland soils has accelerated since 2010 due to no-tillage and increased fertilizer use. Long-term no-till has increased total soil C in cropland over a 30-year time period.

 Tennessee:

• A state-wide assessment revealed that SOC stock responded significantly to management practices, and these responses were prominent in shallow soil layers compared to deeper layers. Intensively managed rotational pastures with long duration presence of livestock and long-term no-till row crop systems with organic inputs increased SOC stock the most. When biophysical and management drivers of SOC accumulation were evaluated, precipitation and normalized difference vegetation index (NDVI) were dominant biophysical drivers in the topsoil across both crop and pasture systems. In row crop farms, cropping diversity and organic inputs were the dominant management drivers and in pasture systems, grazing and cropping diversity were the management drivers. Subsoil SOC stock in both systems was primarily shaped by biophysical drivers - precipitation, NDVI, clay in row crop systems and clay and NDVI in pasture systems.
• We also assessed SOC accumulation in a silvopasture system and found that tree age and distance from tree base significantly influence SOC storage. Specifically, SOC stock down to 60 cm was 18% greater at 0.5 m from 7-year-old trees compared to the grass-dominated alleyways at 15 m, whereas 4-ear-old trees showedno variation in SOC stock across distance.

Florida:

• Bhadha ,J. (PI). USDA NRCS. Florida Everglades Agricultural Area CEAP Watershed. 09/2025 – 09/2030. $1,030,587.

Tennesee:

•  Jagadamma, S. (PI,; Kelly, H. (Co-PI). Row crop production under climate change – assessment of sustainable management practices and plant and soil health. USDA-ARS-Cooperative Agreement. 07/2024 to 06/2025. $103,704
• Jagadamma, S. (PI), Griffith, A., Saha, D. (Co-PIs). Integration of agroforestry as a transformative solution to climate change mitigation and adaptation in organic farms.. The Organic Center-Foundation of Food and Agriculture Research. 01/2023 to 12/2025. $200,000

Publications:

Florida:

• Guo, Y., Silveira, M.L., Bhadha, J.H., Boughton, E.H., Qiu, J. 2025. Divalent cations outweigh metal oxides in stabilizing organic carbon in humid subtropical grassland soils. Geoderma. 463: 117601. https://doi.org/10.1016/j.geoderma.2025.117601
• Jesmin, T., Rabbany, A., Sharma, L., Griffin, W., Upadhyaya, Y.R., Singh, H., Kaur, N., Brym, Z., Serrano, T., Williams, A., Bhadha, J.H. 2025. Evaluating the effects of industrial hemp cultivation on soil quality in Florida. Agrosystems, Geosciences and Environment. 8:e70231. https://doi.org/10.1002/agg2.70231
• Melkani, S., Manirakiza, N., Magana, G., Dold, B., Rabbany, A., VanWeelden, M., Bhadha, J.H. 2025. Pre-flooding phosphorus-iron interactions and nutrient uptake under flooded rice cultivation in histosols of South Florida. Journal of Plant Nutrition. https://doi.org/10.1080/01904167.2025.2563297
• Bai, X., Smidt, S.J., Her, Y.G., Li, Y., Kim, D., Manirakiza, N., Duriancik, L., Bhadha, J.H. 2025. Sensitivity of redox conditions to irrigation practice and organic matter decomposition in a rotational flooded rice (Oryza sativa) cropping system. Journal of Environmental Quality. https://doi.org/10.1002/jeq2.70087
• Santos, F., Filho, M.R., Soares, J.R., Jesmin, T., Manirakiza, N., Silveira, M.C., Mendes, I.C., Oliveira, M.I.,  Melkani, S., Freitas, A.C., Malaquias, J.V., Bhadha, J.H. 2025. Organic matter: a critical soil health indicator in agrosystems within the Cerrado of Bahia, Brazil and South Florida, USA. Frontiers in Soil Science. 5. https://doi.org/10.3389/fsoil.2025.1524550
• Kim, D., Wade, T., Brym, Z., Ogisma, L., Bhattarai, R., Bai, X., Bhadha, J.H., Her, Y. 2025. Assessing the agricultural, environmental, and economic effects of crop diversity management: A comprehensive review on crop rotation and cover crop practices. Journal of Environmental Management. 387. https://doi.org/10.1016/j.jenvman.2025.125833
• Melkani, S., Manirakiza, N., Rabbany, A., Medina-Irizarry, N., Smidt, S., Braswell, A., Martens-Habbena, W., Bhadha, J.H. 2025. Understanding the mechanisms of hydrolytic enzyme mediated organic matter decomposition under different land covers within a subtropical preserve. Frontiers in Environmental Science. 13: https://doi.org/10.3389/fenvs.2025.1564047
• Manirakiza, N., Melkani, S., Rabbany, A., Medina-Irizarry, N., Smidt, S., Braswell, A., Martens-Habbena, W., Bhadha, J.H. 2025. Responses of soil health to seasonal change under different land cover types in a sub-tropical preserve ecosystem. PLOS ONE. 20(3): e0318092. https://doi.org/10.1371/journal.pone.0318092
• Xu, N., Bhadha, J.H., Rabbany, A., Swanson, S., McCray, J.M., Li, Y., Strauss, S.L., Mylavarapu, R.S. 2025. Soil health assessment of incorporating bagasse in a commercial sugarcane production system on mineral soils. Journal of Plant Nutrition and Soil Science. https://doi.org/10.1002/jpln.202300355
• Jesmin, T., Amgain, N.R., Rabbany, A., Manirakiza N., Capasso, J., Korus, K., Bhadha, J.H. 2024. On farm soil health assessment across seven sub-tropical cover crop management systems. Agrosystems, Geosciences & Environment. 8:e70022. https://doi.org/10.1002/agg2.70022

Minnesota:

• Koehler, A., K Phillips, K. Chute, M. Gorman, and Gutknecht. 2025. Life Cycle Assessment of Kernza perennial grain in organic and nonorganic production systems in Minnesota. ACS Sustainable Resource Management. Accepted for publication
• Jilling, A., Grandy, A.S., Daly, A.B. et al. Evidence for the existence and ecological relevance of fast-cycling mineral-associated organic matter. Commun Earth Environ 6, 690 (2025). https://doi-org.ezp3.lib.umn.edu/10.1038/s43247-025-02681-8
• Garg, A., Kwakye, S., Cates, A., Peterson, H., Labine, K., Olson, G., & Sharma, V. 2025. Integrated soil health management influences soil properties: Insights from a US Midwest study. Geoderma, 455, 117214.
• Buell, Z. W., Dabbs, J., Steinweg, J. M., Kluber, L. A., Phillips, J. R., Yang, Z. K., ... & Mayes, M. A. 2025. Interrelationships among methods of estimating microbial biomass across multiple soil orders and biomes. Soil Biology and Biochemistry, 109844.
• Bergquist, G., Sheaffer, C., Rakkar, M., Wyse, D., Jungers, J., & Gutknecht, J. 2025. Soil microbial and plant biomass carbon allocation within perennial and annual grain cropping systems. Agriculture, Ecosystems & Environment, 383, 109535.

Michigan:

• Tiemann, L.K., Oldfield, E.E., Popat, I., Lavallee, J., and Raffeld, A. 2025. Biochar and Climate Outcomes: Literature Review and Technical Guidance. Technical Advisory Network on Climate Smart Agricultural Practices. Zenodo. DOI: 10.5281/zenodo.15890501.
• Kristy, B., Davidson, J., Evans, S.E., and Tiemann, L.K. 2025. Reduced soil diazotroph diversity decreases nitrogen fixation rates, but depends on land management. Applied Soil Ecology 211:106152. DOI: 10.1016/j.apsoil.2025.106152.

North Dakota:

•  Batool, M., J. Cihacek, and R. S. Alghamdi. 2024. Soil Inorganic Carbon, Formation and the Sequestration of Secondary Carbonates in Global Carbon Pools: A Review. Soil Syst. 8(1):15 doi:10.3390/soilsystems8010015.
• Cabello-Leiva, S., M. T. Berti, D. W. Franzen, Cihacek, and T Peters. 2024. Can Nitrogen in fall-planted cover crops be useful to a subsequent maize crop? J Soil Water Cons. 79(2):99-112. doi:10.2489/jswc.2024.00048.
• Ajayi-Banji, A., Cihacek, S. Rahman, S. Sunoj, and C. Igathinathane. 2025. Mineral nitrogen availability from co-digested biodigester products as affected by feedstock pretreatment. Soil Sci. Soc. Am J. 89, e70005. https://doi.org/10.1002/saj2.70005.
• Cabello-Leiva, S., M. T. Berti, D. W. Franzen, Cihacek, T. Peters, D. Samarappuli, and A. Wick. 2025. Do fall-seeded cover crops affect sugarbeet establishment, production, and nutrient cycling? In Hatano, R Baggs, E.M. (eds) Nitrogen Cycling and Soil health. NCHS 2022. Progress in Soil Science. Springer, Singapore. https://doi.org/10.1007/978-981-96-1132-4_10
• Batool, M., L. J. Cihacek, and R. S. Alghamdi. (2025). Coarse carbonate fragments (CCFs) and their contribution to the soil carbon stocks in the northern Great Plains, USA. Geoderma 463 (2025) 117568. https://doi.org/10.1016/j.geoderma.2025.117568.

 Tennessee:

•  Albert-Black, C., D. Saha, J. A. Franklin, A. Wright, S. Kolodney, and S. Jagadamma.  2025. Trees for soil organic carbon storage in a temperate organic agroforestry system.  Soil Science Society of America Journal, 89(3), e70080
• Eeswaran, R., P. A. Lazicki, A. Mengistu, and S, Jagadamma. 2026. Biophysical and management drivers of soil organic carbon accumulation in operational farms across Tennessee, USA. Soil and Tillage Research, 257, 106977

 USDA (Olk):

• Zhang, Z.L.,Olk, D.C., Espina, L.A., Roel-Rezk, V., Linquist, B.A. 2025. Agronomic performance and nitrogen management of continuous rice systems following a year-long fallow. Agronomy Journal 117
• Chantigny, M.H.,Olk, D.C. and Angers, D.A. 2025 Investigating the nature of soil carbohydrates and amino compounds with liquid chromatography. Soil Science Society of America Journal 89:e270018. https://doi.org/10.1002/saj2.70018
• Zhang, Z.L., Olk, D.C. and Linquist, B.A. 2025. Introduction of a Fallow Year to Continuous Rice Systems Enhances Crop Soil Nitrogen Uptake. European Journal of Soil Science.  76:e70046. https://doi.org/10.1111/ejss.70046
• Chatterjee, A., Santiago, E.R.,Hummes, A., Dinnes, D.L., Olk, D.C. 2025. SLAKES Smartphone Application to Identify the Difference in Soil Aggregate Stability Under Cover Crop Management for Soils with Fragipan Horizon. Communications In Soil Science and Plant Analysis 56: 1264-1271. 10.1080/00103624.2025.2452177
• Chatterjee, A.,Santiago, E.R. Dinnes, D.L. Olk, D.C. 2025. Can adoption of multispecies cover crop mixtures improve soil water movement in fragipan soils of southern Illinois?  Vadose Zone Journal. 24:e70046. https://doi.org/10.1002/vzj2.70046.
• Clark, C.M., Dolda, S., Singh, U., Delgado, J.A., Hopkins, B.G, Olk, D.C., Pavuluri, K., Roy, A., Venterea, R., Wilson, M., Fugice, J. 2025. Environmental sustainability of future fertilizers: Tradeoffs between ammonia volatilization and nitrate leaching for 11 enhanced efficiency fertilizers.  Journal of Plant Nutrition (in press).