Adaptive multi-paddock grazing enhances soil carbon and nitrogen stocks and stabilization through mineral association in southeastern U.S. grazing lands

Simulating adaptive grazing management on soil organic carbon in the Southeast U.S.A. using MEMS 2

Grazing lands play a significant role in global carbon (C) dynamics, holding substantial soil organic carbon (SOC) stocks. However, historical mismanagement (e.g., overgrazing and land-use change) has led to substantial SOC losses. Regenerative practices, such as adaptive multi-paddock (AMP) grazing, offer a promising avenue to improve soil health and help combat climate change by increasing SOC accrual, both in its particulate (POC) and mineral-associated (MAOC) organic C components. Because adaptive grazing patterns emerge from the combination of different levers such as frequency, intensity, and timing of grazing, studying AMP grazing management in experimental trials and representing it in models remains challenging. Existing ecosystem models lack the capacity to predict how different adaptive grazing levers affect SOC storage and its distribution between POC and MAOC and along the soil profile accurately. Therefore, they cannot adequately assist decision-makers in effectively optimizing adaptive practices based on SOC outcomes. Here, we address this critical gap by developing version 2.34 of the MEMS 2 model. This version advances the previous by incorporating perennial grass growth and grazing submodules to simulate grass green-up and dormancy, reserve organ dynamics, the influence of standing dead plant mass on new plant growth, grass and supplemental feed consumption by animals, and their feces and urine input to soil. Using data from grazing experiments in the southeastern United States and experimental SOC data from two conventional and three AMP grazing sites in Mississippi, we tested the capacity of MEMS 2.34 to simulate grass forage production, total SOC, POC, and MAOC dynamics to 1-m depth. Further, we manipulated grazing management levers, i.e., timing, intensity, and frequency, to do a sensitivity analysis of their effects on SOC dynamics in the long term. Our findings indicate that the model can represent bahiagrass forage production (BIAS = 9.51 g C m-2, RRMSE = 0.27, RMSE = 65.57 g C m-2, R2 = 0.72) and accurately captured the dynamics of SOC fractions across sites and depths (0-15 cm: RRMSE = 0.05; 15-100 cm: RRMSE = 1.08-2.07), aligning with patterns observed in the measured data. The model best captured SOC and MAOC stocks across AMP sites in the 0-15 cm layer, while POC was best predicted at-depth. Otherwise, the model tended to overestimate SOC and MAOC below 15 cm, and POC in the topsoil. Our simulations indicate that grazing frequency and intensity were key levers for enhancing SOC stocks compared to the current management baseline, with decreasing grazing intensity yielding the highest SOC after 50 years (63.7-65.9 Mg C ha-1). By enhancing our understanding of the effects of adaptive grazing management on SOC pools in the southeastern U.S., MEMS 2.34 offers a valuable tool for researchers, producers, and policymakers to make AMP grazing management decisions based on potential SOC outcomes.

Climate impacts of alternative beef production systems depend on the functional unit used: Weight or monetary value

Beef production has been identified as a significant source of anthropogenic greenhouse gas (GHG) emissions in the agricultural sector. United States and Canada account for about a quarter of the world's beef supply. To compare the GHG emission contributions of alternative beef production systems, we conducted a meta-analysis of 32 studies that were conducted between 2001 and 2023. Results indicated that GHG emissions from beef production in North America varied almost fourfold from 10.2 to 37.6 with an average of 21.4 kg CO2e/kg carcass weight (CW). Studies that considered soil C sequestration (C-seq) reported the highest mitigation potential in GHG emissions (80%), followed by growth enhancement technology (16%), diet modification (6%), and grazing management improvement (7%). Our study highlights the implications of using carbon intensity per economic activity (i.e., GHG emissions per monetary unit), compared to the more common metric of intensity on per weight of product basis (GHG emissions per kg CW) for comparisons across differentiated beef cattle products. While a positive association was found between the proportion of lifespan on grassland and the conventional weight-based indicator, grass-finished beef was found to have lower carbon intensity per economic activity than feedlot-finished beef. Our study emphasizes the need to incorporate land use and management effects and soil C-seq as fundamental aspects of beef GHG emissions and mitigation assessments.

Fine Mapping of QTLs for Alkaline Tolerance in Crucian Carp (Carassius auratus) Using Genome-Wide SNP Markers

Crucian carp (Carassius auratus) is widely distributed in the world and has become an economically freshwater fish. The population in Lake Dali Nur can tolerate the extreme alkaline environment with alkalinity over 50 mmol/L (pH 9.6), thus providing a special model for exploring alkali-tolerant molecular markers in an extremely alkaline environment. In this study, we constructed a high-density and high-resolution linkage map with 16,224 SNP markers based on genotyping-by-sequencing (GBS) consisting of 152 progenies and conducted QTL studies for alkali-tolerant traits. The total length of the linkage map was 3918.893 cM, with an average distance of 0.241 cM. Two QTLs for the ammonia-N-tolerant trait were detected on LG27 and LG45. A QTL for the urea-N-tolerant trait was detected on LG27. Interestingly, mapping the two QTLs on LG27 revealed that the mapped genes were both located in the intron of CDC42. GO functional annotation and KEGG enrichment analysis results indicated that the biological functions might be involved in the cell cycle, cellular senescence, MAPK, and Ras signaling pathways. These findings suggest that CDC42 may play an important role in the process of dealing with extremely alkaline environments.

Importance of on-farm research for validating process-based models of climate-smart agriculture

Climate-smart agriculture can be used to build soil carbon stocks, decrease agricultural greenhouse gas (GHG) emissions, and increase agronomic resilience to climate pressures. The US recently declared its commitment to include the agricultural sector as part of an overall climate-mitigation strategy, and with this comes the need for robust, scientifically valid tools for agricultural GHG flux measurements and modeling. If agriculture is to contribute significantly to climate mitigation, practice adoption should be incentivized on as much land area as possible and mitigation benefits should be accurately quantified. Process-based models are parameterized on data from a limited number of long-term agricultural experiments, which may not fully reflect outcomes on working farms. Space-for-time substitution, paired studies, and long-term monitoring of SOC stocks and GHG emissions on commercial farms using a variety of climate-smart management systems can validate findings from long-term agricultural experiments and provide data for process-based model improvements. Here, we describe a project that worked collaboratively with commercial producers in the Midwest to directly measure and model the soil organic carbon (SOC) stocks of their farms at the field scale. We describe this study, and several unexpected challenges encountered, to facilitate further on-farm data collection and the creation of a secure database of on-farm SOC stock measurements.

High stocking rates effects in continuous season long grazing reduces the contribution of microbial necromass to soil organic carbon in a semi-arid grassland in Inner Mongolia

Livestock grazing strongly influences the accumulation of soil organic carbon (SOC) in grasslands. However, whether the changes occurring in SOC content under different intensities of continuous summer long grazing are associated with the changes in microbially-derived necromass C remains unclear. Here, we established a sheep grazing experiment in northern China in 2004 with four different stocking rates. Soil samples were collected after 17 years of grazing and analyzed for physical, chemical, and microbial characteristics. Grazing decreased SOC and microbial necromass carbon (MNC). Notably, grazing also diminished contributions of MNC to SOC. MNC declined with decreasing plant carbon inputs with degradation of the soil environment. Direct reductions in microbial necromass C, which indirectly reduced SOC, resulted from reduced in plant C inputs and microbial abundance and diversity. Our study highlights the key role of stocking rate in governing microbial necromass C and SOC and the complex relationships these variables.

Ruminating on soil carbon: Applying current understanding to inform grazing management

Among options for atmospheric CO2 removal, sequestering soil organic carbon (SOC) via improved grazing management is a rare opportunity because it is scalable across millions of globally grazed acres, low cost, and has high technical potential. Decades of scientific research on grazing and SOC has failed to form a cohesive understanding of how grazing management affects SOC stocks and their distribution between particulate (POM) and mineral-associated organic matter (MAOM)-characterized by different formation and stabilization pathways-across different climatic contexts. As we increasingly look to grazing management for SOC sequestration on grazinglands to bolster our climate change mitigation efforts, we need a clear and collective understanding of grazing management's impact on pathways of SOC change to inform on-the-ground management decisions. We set out to review the effects of grazing management on SOC through a unified plant ecophysiology and soil biogeochemistry conceptual framework, where elements such as productivity, input quality, soil mineral capacity, and climate variables such as aridity co-govern SOC accumulation and distribution into POM and MAOM. To maximize applicability to grazingland managers, we discuss how common management levers that drive overall grazing pattern, including timing, intensity, duration, and frequency can be used to optimize mechanistic pathways of SOC sequestration. We discuss important research needs and measurement challenges, and highlight how our conceptual framework can inform more robust research with greater applicability for maximizing the use of grazing management to sequester SOC.

Distinct, direct and climate-mediated environmental controls on global particulate and mineral-associated organic carbon storage

Identifying controls on soil organic carbon (SOC) storage, and where SOC is most vulnerable to loss, are essential to managing soils for both climate change mitigation and global food security. However, we currently lack a comprehensive understanding of the global drivers of SOC storage, especially with regards to particulate (POC) and mineral-associated organic carbon (MAOC). To better understand hierarchical controls on POC and MAOC, we applied path analyses to SOC fractions, climate (i.e., mean annual temperature [MAT] and mean annual precipitation minus potential evapotranspiration [MAP-PET]), carbon (C) input (i.e., net primary production [NPP]), and soil property data synthesized from 72 published studies, along with data we generated from the National Ecological Observatory Network soil pits (n = 901 total observations). To assess the utility of investigating POC and MAOC separately in understanding SOC storage controls, we then compared these results with another path analysis predicting bulk SOC storage. We found that POC storage is negatively related to MAT and soil pH, while MAOC storage is positively related to NPP and MAP-PET, but negatively related to soil % sand. Our path analysis predicting bulk SOC revealed similar trends but explained less variation in C storage than our POC and MAOC analyses. Given that temperature and pH impose constraints on microbial decomposition, this indicates that POC is primarily controlled by SOC loss processes. In contrast, strong relationships with variables related to plant productivity constraints, moisture, and mineral surface availability for sorption indicate that MAOC is primarily controlled by climate-driven variations in C inputs to the soil, as well as C stabilization mechanisms. Altogether, these results demonstrate that global POC and MAOC storage are controlled by separate environmental variables, further justifying the need to quantify and model these C fractions separately to assess and forecast the responses of SOC storage to global change.

Grazing management for soil carbon in Australia: A review

The livestock industry accounts for a considerable proportion of agricultural greenhouse gas emissions, and in response, the Australian red meat industry has committed to an aspirational target of net-zero emissions by 2030. Increasing soil carbon storage in grazing lands has been identified as one method to help achieve this, while also potentially improving production and provision of other ecosystem services. This review examined the effects of grazing management on soil carbon and factors that drive soil carbon sequestration in Australia. A systematic literature search and meta-analysis was used to compare effects of stocking intensity (stocking rate or utilisation) and stocking method (i.e, continuous, rotational or seasonal grazing systems) on soil organic carbon, pasture herbage mass, plant growth and ground cover. Impacts on below ground biomass, soil nitrogen and soil structure are also discussed. Overall, no significant impact of stocking intensity or method on soil carbon sequestration in Australia was found, although lower stocking intensity and incorporating periods of rest into grazing systems (rotational grazing) had positive effects on herbage mass and ground cover compared with higher stocking intensity or continuous grazing. Minimal impact of grazing management on pasture growth rate and below-ground biomass has been reported in Australia. However, these factors improved with grazing intensity or rotational grazing in some circumstances. While there is a lack of evidence in Australia that grazing management directly increases soil carbon, this meta-analysis indicated that grazing management practices have potential to benefit the drivers of soil carbon sequestration by increasing above and below-ground plant production, maintaining a higher residual biomass, and promoting productive perennial pasture species. Specific recommendations for future research and management are provided in the paper.

Grazing management impacts on ecosystem services under contrasting climatic conditions in Texas and North Dakota

Grazing management is an important factor affecting the delivery of ecosystem services at the watershed scale. Moreover, characterizing the impacts of climate variation on water resources is essential in managing rangelands. In this study, the effects of alternative grazing management scenarios on provisioning, regulating, and supporting services were assessed in two watersheds with contrasting climates; the Lower Prairie Dog Town Fork Red River (LPDTFR) Watershed in North Texas and the Apple Watershed in South Dakota. The impacts of heavy stocking continuous grazing, light stocking continuous grazing, Adaptive Multi-Paddock (AMP) grazing, and an ungrazed exclosure were compared using the Soil and Water Assessment Tool (SWAT) model. Our results indicate that the quantity of snow and timing of snow melt substantially influenced grazing management effects on ecosystem services in the Apple Watershed. In contrast, precipitation was the main factor influencing these effects in the LPDTFR Watershed because it highly affected the variation in water cycling, streamflow, sediment, and nutrient controls. Simulated results indicated that AMP grazing was the optimal grazing management approach for enhancing water conservation and ecosystem services in both watersheds regardless of climatic conditions. The Apple Watershed, which is a snow-dominated watershed, exhibited greater ecosystem service improvements under AMP grazing (50.6%, 58.7%, 74.4%, 61.5% and 72.6% reduction in surface runoff, streamflow, and sediment, total nitrogen (TN) and total phosphorus (TP) losses, respectively as compared to HC grazing) than the LPDTFR Watershed (46.0%, 22.8%, 34.1%, 18.9% and 38.4% reduction in surface runoff, streamflow, and sediment, TN and TP losses, respectively). Our results suggest that improved grazing management practices enhance ecosystem services and water catchment functions in rangeland-dominated areas, especially in colder climates.

Comparative analysis of soil organic matter fractions, lability, stability ratios, and carbon management index in various land use types within bharatpur catchment, Chitwan District, Nepal

BACKGROUND

Land use and land cover changes have a significant impact on the dynamics of soil organic matter (SOM) and its fractions, as well as on overall soil health. This study conducted in Bharatpur Catchment, Chitwan District, Nepal, aimed to assess and quantify variations in total soil organic matter (TSOMC), labile organic matter fraction (CL), stable organic matter fraction (CS), stability ratio (SR), and carbon management index (CMI) across seven land use types: pastureland, forestland, fruit orchards, small-scale conventional agricultural land, large-scale conventional agricultural land, large-scale alternative fallow and conventional agricultural land, and organic farming agricultural land. The study also explored the potential use of the Carbon Management Index (CMI) and stability ratio (SR) as indicators of soil degradation or improvement in response to land use changes.

RESULTS

The findings revealed significant differences in mean values of TSOMC, CL, and CS among the different land use types. Forestland and organic farming exhibited significantly higher TSOMC (3.24%, 3.12%) compared to fruit orchard lands (2.62%), small scale conventional farming (2.22%), alternative fallow and conventional farming (2.06%), large scale conventional farming (1.84%) and pastureland (1.20%). Organic farming and Forestland also had significantly higher CL (1.85%, 1.84%) and CS (1.27%, 1.39%) compared to all other land use types. Forest and organic farming lands showed higher CMI values, while pastures and forests exhibited higher SR values compared to the rest of the land use types.

CONCLUSIONS

This study highlights the influence of various land use types on soil organic matter pools and demonstrates the potential of CMI and SR as indicators for assessing soil degradation or improvement in response to land use and land cover changes.

Unlocking complex soil systems as carbon sinks: multi-pool management as the key

Much research focuses on increasing carbon storage in mineral-associated organic matter (MAOM), in which carbon may persist for centuries to millennia. However, MAOM-targeted management is insufficient because the formation pathways of persistent soil organic matter are diverse and vary with environmental conditions. Effective management must also consider particulate organic matter (POM). In many soils, there is potential for enlarging POM pools, POM can persist over long time scales, and POM can be a direct precursor of MAOM. We present a framework for context-dependent management strategies that recognizes soils as complex systems in which environmental conditions constrain POM and MAOM formation.

A systematic review on whether regenerative agriculture improves animal welfare: A qualitative analysis with a One Welfare perspective

The welfare of animals in food-production systems is a cause of concern to the public. Regenerative agriculture was first used by the Rodale Institute and proposes to regenerate degraded components of ecosystems, aiming to be more than just sustainable. However, despite animal welfare being pushed to be part of the SDG agenda for 2030, there is no clarity on how regenerative agriculture impacts animal welfare. It is challenging to determine regenerative agriculture impacts on animal welfare, since it is not entirely defined. One Welfare could help define entry points for future research by studying animal welfare in connection with human welfare and environmental conservation. We aimed to analyse the extent to which positive animal welfare outcomes characterise regenerative agriculture systems in peer-reviewed articles and whether the narratives of such articles support that regenerative agriculture promotes animal welfare directly or indirectly by improving human welfare and environmental conservation. We searched papers including 'regenerative agriculture' using PRISMA-P, selecting animal welfare, human welfare, environment conservation terms, developed themes, and carried out analysis using Atlas.Ti8 and Causal Loop Diagram. We found that papers mainly linked animal welfare to animal health, human welfare to financial farm status and farmer's self-awareness, and environmental conservation to soil improvement. Causal Loop Diagram indicated that regenerative agriculture had the potential to improve the health and nutrition components of animal welfare by enhancing financial farmers' status/self-awareness (human welfare), and the soil (environmental conservation), reflecting that the processes that affect human welfare and environmental conservation could also affect animal welfare. However, information in papers remains insufficient to determine how regenerative agriculture impacts on animal welfare and research into regenerative agriculture needs to extend its focus on animal welfare and elucidate the regenerative agriculture principles leading to animal welfare.

Grazing Cattle, Sheep, and Goats Are Important Parts of a Sustainable Agricultural Future

Many people believe that animal agriculture should be phased out and replaced with vegetarian substitutes. The livestock industry has also been attacked because it uses vast amounts of land. People forget that grazing cattle or sheep can be raised on land that is either too arid or too rough for raising crops. At least 20% of the habitable land on Earth is not suitable for crops. Rotational grazing systems can be used to improve both soil health and vegetation diversity on arid land. Grazing livestock are also being successfully used to graze cover crops on prime farmland. Soil health is improved when grazing on a cover crop is rotated with conventional cash crops, such as corn or soybeans. It also reduces the need for buying fertilizer. Grazing animals, such as cattle, sheep, goats, or bison, should be used as part of a sustainable system that will improve the land, help sequester carbon, and reduce animal welfare issues.

Grassland soil carbon sequestration: Current understanding, challenges, and solutions

Grasslands store approximately one third of the global terrestrial carbon stocks and can act as an important soil carbon sink. Recent studies show that plant diversity increases soil organic carbon (SOC) storage by elevating carbon inputs to belowground biomass and promoting microbial necromass contribution to SOC storage. Climate change affects grassland SOC storage by modifying the processes of plant carbon inputs and microbial catabolism and anabolism. Improved grazing management and biodiversity restoration can provide low-cost and/or high-carbon-gain options for natural climate solutions in global grasslands. The achievable SOC sequestration potential in global grasslands is 2.3 to 7.3 billion tons of carbon dioxide equivalents per year (CO₂e year^-1) for biodiversity restoration, 148 to 699 megatons of CO₂e year^-1 for improved grazing management, and 147 megatons of CO₂e year^-1 for sown legumes in pasturelands.

Land-based climate solutions for the United States

Meeting end-of-century global warming targets requires aggressive action on multiple fronts. Recent reports note the futility of addressing mitigation goals without fully engaging the agricultural sector, yet no available assessments combine both nature-based solutions (reforestation, grassland and wetland protection, and agricultural practice change) and cellulosic bioenergy for a single geographic region. Collectively, these solutions might offer a suite of climate, biodiversity, and other benefits greater than either alone. Nature-based solutions are largely constrained by the duration of carbon accrual in soils and forest biomass; each of these carbon pools will eventually saturate. Bioenergy solutions can last indefinitely but carry significant environmental risk if carelessly deployed. We detail a simplified scenario for the United States that illustrates the benefits of combining approaches. We assign a portion of non-forested former cropland to bioenergy sufficient to meet projected mid-century transportation needs, with the remainder assigned to nature-based solutions such as reforestation. Bottom-up mitigation potentials for the aggregate contributions of crop, grazing, forest, and bioenergy lands are assessed by including in a Monte Carlo model conservative ranges for cost-effective local mitigation capacities, together with ranges for (a) areal extents that avoid double counting and include realistic adoption rates and (b) the projected duration of different carbon sinks. The projected duration illustrates the net effect of eventually saturating soil carbon pools in the case of most strategies, and additionally saturating biomass carbon pools in the case of forest management. Results show a conservative end-of-century mitigation capacity of 110 (57-178) Gt CO₂ e for the U.S., ~50% higher than existing estimates that prioritize nature-based or bioenergy solutions separately. Further research is needed to shrink uncertainties, but there is sufficient confidence in the general magnitude and direction of a combined approach to plan for deployment now.

Adaptive multi-paddock grazing management's influence on soil food web community structure for: increasing pasture forage production, soil organic carbon, and reducing soil respiration rates in southeastern USA ranches

Background

Measurement of two grazing management's influence on pasture productivity, soil food web structure, soil organic carbon and soil microbial respiration efficiency was conducted on five southeastern US, across-the-fence ranch pairs to compare adaptive multi-paddock grazing (AMP) management, using short grazing events with planned, adaptive recovery periods, to conventional grazing (CG) management, with continuous grazing at low stock density.

Methodology

A point-in-time experimental field analysis was conducted to compare five AMP or CG ranch pairs to better understand the influence of grazing management on (a) standing crop biomass productivity; (b) soil food web community population, structure and functionality; (c) soil organic carbon accrual; and d) soil-C (CO₂) respiration kinetics.

Results

AMP grazing systems outperformed CG systems by generating: (a) 92.68 g m^-2 more standing crop biomass (SCB), promoting 46% higher pasture photosynthetic capacity (Two sample Mann-Whitney; Z = 6.1836; no DF in MW; p = 6.26 × 10^-10; Effect size = 0.35) (b) a strong positive linear relationship of SCB with fungal biomass (R = 0.9915; F(1,3) = 175.35; p = 0.015); fungal to bacterial (F:B) biomass ratio (R = 0.9616; F(1,3) = 36.75; p = 0.009) and a soil food web proxy (R = 0.9616; F(1,3) = 36.75; p = 0.009) and a concurrent very strong inverse relationship with bacteria biomass (R = -0.946; F(1,3) = 25.56; p = 0.015); (c) significant predator/prey interactions with an inverse relationship with bacterial population biomass (R =  - 0.946; F(1,3) = 25.56; p = 0.015) and a positive relationship with total protozoa enumeration (R = 0.9826; F(1,3) = 83.68; p = 0.003) when compared to SCB; (d) a 19.52% reduction in soil C (CO₂) respiration rates (Two sample t-test; T = -2.3581; DF = 52.3541; p = 0.0221; Effect size = 0.59); and (e) a 20.6% increase in soil organic carbon (SOC) in the top 10 cm of soil profile (Two sample Mann-Whitney; Z = 2.6507; no DF in MW; p = 0.008; Effect size = 0.24). Rancher conversion to AMP grazing strategies would appear to regenerate soil food web population, structure, diversity and biological functionality helping to improve: carbon flow into plant biomass, buildup of soil carbon, predator/prey nutrient cycling and soil microbial respiration efficiency while offering improved climate resilience and a strategy to increase the capture and storage of atmospheric CO₂ in soils of the world's rangeland.

Persistent soil carbon enhanced in Mollisols by well-managed grasslands but not annual grain or dairy forage cropping systems

Soil organic carbon (C) responses to agricultural management are highly uncertain, hindering our ability to assess the C sequestration potential of croplands and develop sound policies to mitigate climate change while enhancing other ecosystem services. Combining experimental evidence from a long-term field experiment and a meta-analysis of published literature, we show that the accrual of mineral-associated soil C in intensively managed Mollisols was only achieved by managing ruminant grazing on perennial grasslands. Although modifying dominant grain-based systems with reduced tillage, diversified rotations, and legumes and manure additions improve soil health metrics—which is critical to soil, nutrient, and water conservation—they are unlikely to enhance persistent forms of soil C in Mollisols to help drawdown atmospheric C and stabilize climate.

Intensive crop production on grassland-derived Mollisols has liberated massive amounts of carbon (C) to the atmosphere. Whether minimizing soil disturbance, diversifying crop rotations, or re-establishing perennial grasslands and integrating livestock can slow or reverse this trend remains highly uncertain. We investigated how these management practices affected soil organic carbon (SOC) accrual and distribution between particulate (POM) and mineral-associated (MAOM) organic matter in a 29-y-old field experiment in the North Central United States and assessed how soil microbial traits were related to these changes. Compared to conventional continuous maize monocropping with annual tillage, systems with reduced tillage, diversified crop rotations with cover crops and legumes, or manure addition did not increase total SOC storage or MAOM-C, whereas perennial pastures managed with rotational grazing accumulated more SOC and MAOM-C (18 to 29% higher) than all annual cropping systems after 29 y of management. These results align with a meta-analysis of data from published studies comparing the efficacy of soil health management practices in annual cropping systems on Mollisols worldwide. Incorporating legumes and manure into annual cropping systems enhanced POM-C, microbial biomass, and microbial C-use efficiency but did not significantly increase microbial necromass accumulation, MAOM-C, or total SOC storage. Diverse, rotationally grazed pasture management has the potential to increase persistent soil C on Mollisols, highlighting the key role of well-managed grasslands in climate-smart agriculture.

Influence mechanisms of iron, aluminum and manganese oxides on the mineralization of organic matter in paddy soil

The mineralization of soil organic matter (SOM) is closely related to the emission of greenhouse gas into atmosphere and the stability of organic carbon in soil. The influence of minerals on SOM mineralization in the specific soil received very few attentions. The influence characteristics and potential mechanisms of oxides on the mineralization of SOM in the paddy soil were observed in this study by incubating soil with the addition (dosage: 10 g kg^-1) of prepared gibbsite, goethite, ferrihydrite or birnessite for 60 days. A sequence control treatment (753 mg CO₂-C kg^-1) > goethite treatment (656 mg CO₂-C kg^-1) ≈ gibbsite treatment (649 mg CO₂-C kg^-1) > birnessite treatment (529 mg CO₂-C kg^-1) > ferrihydrite treatment (441 mg CO₂-C kg ^-1) was found in the cumulative amount of released CO₂ in 60 days of incubation. Oxides especially ferrihydrite significantly decreased the content of dissolved organic matter (DOM) but tended to increase the content of microbial biomass carbon (MBC). The molecular structure of DOM in the paddy soil was simplified by gibbsite, ferrihydrite and birnessite after the incubation. Oxides especially birnessite and ferrihydrite reduced soil pH and the content of soil available N but increased soil redox potential (Eh). All examined oxides especially Fe oxides enhanced soil bacterial abundance but only birnessite significantly affected bacterial composition at phyla level. The stimulation on the immobilization and/or microbial assimilation of labile organic carbon, the modulation on soil basic properties (available N, pH, Eh), and the decrease of the relative abundance of some decomposing bacteria phyla such as Actinobacteria were the potential pathways of oxides in decreasing SOM mineralization.

Influence of beef genotypes on animal performance, carcass traits, meat quality, and sensory characteristics in grazing or feedlot-finished steers

A 2-yr study was conducted to evaluate the effects of beef genotypes and feeding systems on performance, carcass traits, meat quality, and sensory attributes. A 2×2 factorial experiment was used to randomly allocate 60 steers in year 1 (YR1) and 44 steers in year 2 (YR2). The two beef genotypes evaluated were Red Angus (RA), and RA x Akaushi (AK) crossbreed. The steers were allotted to two finishing feeding systems: grazing, a multi-species forage mixture (GRASS) and feedlot finishing, conventional total mixed ration (GRAIN). All steers were slaughtered on the same day, at 26 and 18 mo of age (GRASS and GRAIN, respectively), and carcass data were collected 48 h postmortem. Growth and slaughter characteristics were significantly impacted by the finishing system (P < 0.01), with the best results presented by GRAIN. Beef genotype affected dressing percent (P < 0.01), ribeye area (P = 0.04), and marbling score (P = 0.01). The AK steers had a tendency (P = 0.09) for lower total gain; however, carcass quality scores were greater compared to RA. There was a genotype by system interaction for USDA yield grade (P < 0.01), where it was lower in GRASS compared to GRAIN in both genotypes, and no difference was observed between the two genotypes for any GRASS or GRAIN systems. There was no difference in meat quality or sensory attributes (P > 0.10) between the two genotypes, except that steaks from AK tended to be juicier than RA (P = 0.06). Thawing loss and color variables were impacted by the finishing system (P < 0.01). L* (lightness) and hue angle presented greater values while a* (redness), b* (yellowness), and chroma presented lower values in GRAIN compared to GRASS. Sensory attributes were scored better in GRAIN than GRASS beef (P < 0.01). There was a genotype by system interaction for flavor (P = 0.02), where beef from RA had a lower flavor rating in GRASS than in GRAIN, and no difference was observed for AK. Within each system, no difference was observed for flavor between RA and AK. Beef from steers in GRASS had greater (P < 0.01) WBSF than those from GRAIN. These results indicate that steers from GRAIN had superior performance and carcass merit and that AK enhanced these traits to a greater degree compared to RA. Furthermore, the beef finishing system had a marked impact on the steaks’ sensory attributes and consumer acceptability. The favorable results for texture and juiciness in GRAIN, which likely impacted overall acceptability, may be related to high marbling.

A review of transformative strategies for climate mitigation by grasslands

Grasslands can significantly contribute to climate mitigation. However, recent trends indicate that human activities have switched their net cooling effect to a warming effect due to management intensification and land conversion. This indicates an urgent need for strategies directed to mitigate climate warming while enhancing productivity and efficiency in the use of land and natural (nutrients, water) resources. Here, we examine the potential of four innovative strategies to slow climate change including: 1) Adaptive multi-paddock grazing that consists of mimicking how ancestral herds roamed the Earth; 2) Agrivoltaics that consists of simultaneously producing food and energy from solar panels on the same land area; 3) Agroforestry with a reverse phenology tree species, Faidherbia (Acacia) albida, that has the unique trait of being photosynthetically active when intercropped herbaceous plants are dormant; and, 4) Enhanced Weathering, a negative emission technology that removes atmospheric CO₂ from the atmosphere. Further, we speculate about potential unknown consequences of these different management strategies and identify gaps in knowledge. We find that all these strategies could promote at least some of the following benefits of grasslands: CO₂ sequestration, non-CO₂ GHG mitigation, productivity, resilience to climate change, and an efficient use of natural resources. However, there are obstacles to be overcome. Mechanistic assessment of the ecological, environmental, and socio-economic consequences of adopting these strategies at large scale are urgently needed to fully assess the potential of grasslands to provide food, energy and environmental security.

Voisin Rational Grazing as a Sustainable Alternative for Livestock Production

Current livestock practices do not meet current real-world social and environmental requirements, pushing farmers away from rural areas and only sustaining high productivity through the overuse of fossil fuels, causing numerous environmental side effects. In this narrative review, we explore how the Voisin Rational Grazing (VRG) system responds to this problem. VRG is an agroecological system based on four principles that maximise pasture growth and ruminant intake, while, at the same time, maintaining system sustainability. It applies a wide range of regenerative agricultural practices, such as the use of multispecies swards combined with agroforestry. Planning allows grazing to take place when pastures reach their optimal resting period, thus promoting vigorous pasture regrowth. Moreover, paddocks are designed in a way that allow animals to have free access to water and shade, improving overall animal welfare. In combination, these practices result in increased soil C uptake and soil health, boost water retention, and protect water quality. VRG may be used to provide ecosystem services that mitigate some of the current global challenges and create opportunities for farmers to apply greener practices and become more resilient. It can be said that VRG practitioners are part of the initiatives that are rethinking modern livestock agriculture. Its main challenges, however, arise from social constraints. More specifically, local incentives and initiatives that encourage farmers to take an interest in the ecological processes involved in livestock farming are still lacking. Little research has been conducted to validate the empirical evidence of VRG benefits on animal performance or to overcome VRG limitations.

Restoring Soil Fertility on Degraded Lands to Meet Food, Fuel, and Climate Security Needs via Perennialization

A continuously growing pressure to increase food, fiber, and fuel production to meet worldwide demand and achieve zero hunger has put severe pressure on soil resources. Abandoned, degraded, and marginal lands with significant agricultural constraints—many still used for agricultural production—result from inappropriately intensive management, insufficient attention to soil conservation, and climate change. Continued use for agricultural production will often require ever more external inputs such as fertilizers and herbicides, further exacerbating soil degradation and impeding nutrient recycling and retention. Growing evidence suggests that degraded lands have a large potential for restoration, perhaps most effectively via perennial cropping systems that can simultaneously provide additional ecosystem services. Here we synthesize the advantages of and potentials for using perennial vegetation to restore soil fertility on degraded croplands, by summarizing the principal mechanisms underpinning soil carbon stabilization and nitrogen and phosphorus availability and retention. We illustrate restoration potentials with example systems that deliver climate mitigation (cellulosic bioenergy), animal production (intensive rotational grazing), and biodiversity conservation (natural ecological succession). Perennialization has substantial promise for restoring fertility to degraded croplands, helping to meet future food security needs.

World scientists' warnings into action, local to global

'We have kicked the can down the road once again - but we are running out of road.' - Rachel Kyte, Dean of Fletcher School at Tufts University.We, in our capacities as scientists, economists, governance and policy specialists, are shifting from warnings to guidance for action before there is no more 'road.' The science is clear and irrefutable; humanity is in advanced ecological overshoot. Our overexploitation of resources exceeds ecosystems' capacity to provide them or to absorb our waste. Society has failed to meet clearly stated goals of the UN Framework Convention on Climate Change. Civilization faces an epochal crossroads, but with potentially much better, wiser outcomes if we act now.What are the concrete and transformative actions by which we can turn away from the abyss? In this paper we forcefully recommend priority actions and resource allocation to avert the worst of the climate and nature emergencies, two of the most pressing symptoms of overshoot, and lead society into a future of greater wellbeing and wisdom. Humanity has begun the social, economic, political and technological initiatives needed for this transformation. Now, massive upscaling and acceleration of these actions and collaborations are essential before irreversible tipping points are crossed in the coming decade. We still can overcome significant societal, political and economic barriers of our own making.Previously, we identified six core areas for urgent global action - energy, pollutants, nature, food systems, population stabilization and economic goals. Here we identify an indicative, systemic and time-limited framework for priority actions for policy, planning and management at multiple scales from household to global. We broadly follow the 'Reduce-Remove-Repair' approach to rapid action. To guide decision makers, planners, managers, and budgeters, we cite some of the many experiments, mechanisms and resources in order to facilitate rapid global adoption of effective solutions.Our biggest challenges are not technical, but social, economic, political and behavioral. To have hope of success, we must accelerate collaborative actions across scales, in different cultures and governance systems, while maintaining adequate social, economic and political stability. Effective and timely actions are still achievable on many, though not all fronts. Such change will mean the difference for billions of children and adults, hundreds of thousands of species, health of many ecosystems, and will determine our common future.