No abstract

A life cycle assessment with carbon (C) as the reference unit was used to balance the benefits of land preparation practices of establishing tall-grass prairies as a crop for reclaimed mine land with reduced environmental damage. Land preparation and management practices included disking with sub-soiling (DK-S), disking only (DK), no tillage (NT), and no tillage with grazing (NT-G). To evaluate the C balance and energy use of each of the land preparations, an index of sustainability (I s = C O /C I , Where: C O is the sum of all outputs and C I is the sum of all inputs) was used to assess temporal changes in C.Of the four land preparation and management practices, DK had the highest I s at 8·53. This was due to it having the least degradation of soil organic carbon (SOC) during land-use change (À730 kg ha À1 y À1 ) and second highest aboveground biomass production (9,881 kg ha À1 ). The highest aboveground biomass production occurred with NT (11,130 kg ha À1 ), although SOC losses were similar to DK-S, which on average was 2,899 kg ha À1 y À1 . The I s values for NT and DK-S were 2·50 and 1·44, respectively. Grazing from bison reduced the aboveground biomass to 8,971 kg ha À1 compared with NT with no grazing, although stocking density was low enough that I s was still 1·94. This study has shown that converting from cool-season forage grasses to tall-grass prairie results in a significant net sink for atmospheric CO 2 3 years after establishment in reclaimed mine land, because of high biomass yields compensating for SOC losses from land-use change.

No abstract

No abstract

No abstract

No abstract

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.