A large amount of cattle manure is generated in the US every year, creating challenges for ecosystem sustainability while offering opportunities for value-added products through biorefinery. While methods like land application, composting, and anaerobic digestion are well established for treating cattle manure, advanced biorefinery technologies are needed to enhance the utilization of cattle manure or its digestate. Based on the composition of cattle manure, this review discusses technologies for the biorefinery of cattle manure or its digestate, including the recovery of fiber and protein, and the production of platform chemicals, such as volatile fatty acids, lactic acid, medium-chain carboxylic acids, ethanol, single-cell protein, and lipids. Additionally, this review discusses process integration for simultaneously producing multiple value-added products from cattle manure using various biorefinery technologies. By offering insights into different approaches, this review aims to support the development of integrated biorefinery processes, thereby improving the economic and environmental sustainability of cattle manure management.

Climate change has an impact on soybean production in the USA, necessitating thorough impact studies across broad geographic areas and extended periods to develop appropriate coping strategies. This study investigates the simulated response of soybean in ten major soybean-growing states of the USA under Climate Model Intercomparison Project Phase 5 based on multiple global climate models, two representative concentration pathways [RCP8.5 and RCP4.5] under rainfed and irrigated conditions for 2013–2039, 2043–2069, 2063–2099. The future climate series was developed using Agricultural Model Intercomparison and Improvement Project protocol by applying mean and variability, and CROPGRO-soybean model was explored for soybean simulation under 400 ppm CO₂level and a set of management. Under future climate, intense changes in temperature, precipitation amount and variability are anticipated under RCP8.5 than RCP4.5. As a result, a shorter life cycle, more evapotranspiration, lower grain production, higher water consumption and water productivity were expected under RCP8.5 than RCP4.5 scenarios. A higher reduction in grain yield and water productivity is expected under rainfed than irrigated conditions and intensity increases with advancement towards end of the century. Irrigation tends to decrease adverse climate change effects; however, the marginal economy for irrigation water must be assessed. Since the northern states under study are likely to experience increased grain yields or lower negative impacts, these areas could be the major production zones for soybean production in the future if only climate change is taken into account. Before reaching a convincing conclusion, different adaptation strategies must be thoroughly investigated.

Animal manure is an agricultural by-product that presents both nutrient value and environmental challenges, particularly through nutrient leaching and greenhouse gas (GHG) fluxes. Hydrothermal carbonization (HTC) offers a potential management strategy that converts wet manures into hydrochar, which is a more stable and nutrient-retentive amendment. This study evaluated how hydrochar derived from dairy manure, swine manure, and poultry litter, applied at 15 or 30 metric tons/ha, influences GHG fluxes and corn biomass production in a controlled greenhouse experiment using soil mesocosms with two fertilization histories (dairy-manure vs. inorganic/chemical-only). All treatments received an equal total nitrogen input through combinations of hydrochar-derived N and urea. Hydrochar treatments tended to reduce cumulative N₂O fluxes, although not always significantly, compared to the urea-only control, with the largest reductions occurring after the second urea application. Across feedstocks, hydrochar treatments tended to show higher cumulative CO₂ fluxes, although not statistically significant, relative to the control, with 15 tons/ha applications producing higher CO₂ fluxes and more corn biomass compared to 30 tons/ha. Methane fluxes exhibited no consistent treatment-level trends. Corn biomass tended to be higher in the 15 tons/ha hydrochar treatments and lower in the 30 tons/ha treatments relative to the control. Overall, findings indicate that partially replacing urea fertilizer with hydrochar, can potentially increase biomass while reducing cumulative N₂O fluxes. Generally, the increases in CO₂ fluxes from hydrochar did not fully offset the reductions in N₂O fluxes at the system level. The results suggest that hydrochar amendments can offer an agronomically efficient and environmentally beneficial nutrient-management strategy.

A comprehensive understanding of the potential effects of conservation practices on soil health, crop productivity, and greenhouse gas (GHG) emissions remains elusive, despite extensive research. Thus, the DeNitrification–DeComposition (DNDC) model was employed to evaluate the impact of eleven commonly practiced management scenarios on ecosystem services in the Western Lake Erie Basin, USA, from 1998–2020. Out of eleven scenarios, eight were focused on corn–soybean rotations with varied nitrogen application timing (50% before planting and 50% at either fall or spring during or after planting), or nitrogen source (dairy slurry or synthetic fertilizer (SF)), or tillage practices (conventional, no-till), or cereal rye (CR) in rotation. Remaining scenarios involved rotations with silage corn (SC), winter crops (CR or winter wheat), and alfalfa. The silage corn with winter crop and four years of alfalfa rotation demonstrated enhanced ecosystem services compared to equivalent scenario with three years of alfalfa. Applying half the total nitrogen to corn through SF during or after spring-planted corn increased yield and soil organic carbon (SOC) sequestration while raising global warming potential (GWP) than fall-applied nitrogen. The no-till practice offered environmental benefits with lower GWP and higher SOC sequestration, while resulting in lower yield than conventional tillage. The incorporation of CR into corn–soybean rotations enhanced carbon sequestration, increased GHG emissions, improved corn yield, and lowered soybean yield. Substituting SF with manure for corn production improved corn yield under conventional tillage and increased SOC while increasing GWP under both tillage conditions. While the role of conservation practices varies by site, this study’s findings aid in prioritizing practices by evaluating tradeoffs among a range of ecosystem services.