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Highlights • Extensification of dairy sheep systems provides an environmental benefit when soil C sequestration is considered. • Extensification of dairy sheep systems determines lower environmental impact per hectare of utilized agricultural area. • Enteric methane emissions are the main source of GHG emissions of the sheep milk life cycle. • Carbon sequestration in permanent grasslands can considerably contribute to climate change mitigation. Abstract A life cycle assessment (LCA) study of a transition from semi-intensive to semi-extensive Mediterranean dairy sheep farm suggests that the latter has a strong potential for offsetting greenhouse gas (GHG) emissions through the soil C sequestration (Cseq) in permanent grasslands. The extensification process shows clear environmental advantage when emission intensity is referred to the area-based functional unit (FU). Several LCA studies reported that extensive livestock systems have greater GHG emissions per mass of product than intensive one, due to their lower productivity. However, these studies did not account for soil Cseq of temporary and permanent grasslands, that have a strong potential to partly mitigate the GHG balance of ruminant production systems. Our LCA study was carried out considering the transition from a semi-intensive (SI) towards a semi-extensive (SE) production system, adopted in a dairy sheep farm located in North-Western Sardinia (Italy). Impact scope included enteric methane emissions, feed production, on-farm energy use and transportation, infrastructures as well as the potential C sink arising from soil Cseqwith respect to the emission intensity. In order to provide a more comprehensive analysis, we used the following FUs: 1 kg of fat and protein corrected milk (FPCM) and 1 ha of utilised agricultural area (UAA). We observed that the extensification of production system determined contrasting environmental effects when using different FUs accounting for soil Cseq. When soil Cseq in emission intensity estimate was included, we observed slightly lower values of GHG emissions per kg of FPCM in the SI production system (from 3.37 to 3.12 kg CO2 equivalents – CO2-eq), whereas a greater variation we observed in the SE one (from 3.54 to 2.90 kg CO2-eq). Considering 1 ha of UAA as FU and including the soil Cseq, the emission intensity in SI moved from 6,257 to 5,793 kg CO2-eq, whereas values varied from 4,020 to 3,299 kg CO2-eq in SE. These results indicated that the emission intensity from semi-extensive Mediterranean dairy sheep farms can be considerably reduced through the soil Cseq, although its measurement is influenced by the models used in the estimation.

Field management practices are an important factor in mitigating climate change and increasing agricultural production. However, no study has synthesized the evidence on the efficacy of alternative field management practices and reviewed life cycle assessments that consider all emissions over the entire or part of the life cycle of rice production. Thus, 68 papers were reviewed and grouped into 13 field management categories. The management practices were evaluated in terms of yield, area-scaled greenhouse gas (GHG) emissions, and yield-scaled GHG emissions against base management practices. The yield increase of these field management practices was between -6 % and 12 %, with some exceptions. It was only nonpuddling that simultaneously increased the yield and reduced both the area-scaled GHG and yield-scaled GHG emissions with respect to the base category. Water management, including alternate wetting and drying or single and multiple drainage and no-tillage, performed well in reducing the average area-scaled GHG and yield-scaled GHG emissions, although the average yield was reduced slightly. For the remaining many management practices, the increase in area-scaled GHG emissions was larger than the change in yield, so the yield change had little impact on yield-scaled GHG emissions. The higher increase in area-scaled GHG emissions than the change in yield requires innovative and new approaches, such as implementing alternative management together with water management, of which the effect was observed in some of the papers reviewed in this study. Therefore, this study recommends selecting nonpuddling, water management or no-tillage as climate mitigation management options. The evaluation of field management will be more robust if more impact categories are considered, including missing aspects (i.e., soil fertility)., Competing Interests: Declaration of competing interest The author declares that I have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

In the last few decades, significant changes in livestock farming systems and land use were observed in European mountain areas with large implications for the sustainability of grazing agro-ecosystems. System dynamic studies become essential to understand these changes, identify the drivers involved and trying to anticipate what might happen in the future. The objectives of this study were as follows: (i) to analyse the main recent changes that occurred in mountain cattle farming in the Spanish Pyrenees; (ii) to typify diverse trajectories of evolution of these systems; and (iii) to establish drivers of change that might help understand the evolution of mountain agriculture. A constant sample of mountain cattle farms was analysed for the period 1990 to 2004. In total, 30% of farms have disappeared during this time interval. For the remaining farms, the most important general changes observed were as follows: increment of size; change of productive orientation from mixed beef-dairy to pure beef production; extensification of grazing management; reduction of family labour and increase of pluriactivity; reduction of unitary variable costs; and increase of labour productivity. After the elimination of common temporal effects between dates, multivariate techniques allowed for the identification of three patterns and six specific trajectories of evolution that are profiled in the text. Relationships between the patterns of evolution and other variables referring the farm, the household and the socio-economic environment were identified as drivers of change: (i) the specific location of the farm in relation to the capital village of the municipality and the evolution other sectors of the economy, in particular tourism; (ii) the size of the family labour, presence of successors and degree of dynamism of the farmer; and (iii) the initial orientation of production.

The performance of rotationally grazed beef suckler cows and their progeny to slaughter on two lowland grassland management systems differing in stocking rate (SR) and fertiliser nitrogen (N) level was compared over eight years. The two Systems were 1) Intensive (INT): SR of 0.56 (bull production) or 0.71 (steer production) ha cow - 1 unit, 211 kg fertiliser N ha - 1 , two silage harvests, and 2) Extensive (EXT): SR of 0.69 (bull production) or 0.88 (steer production) ha cow - 1 unit, 97 kg fertiliser N ha - 1 and one staggered silage harvest. A cow unit was defined as a cow plus progeny to slaughter. On the silage harvesting area, the mean application rate for fertiliser N was 110 and 80 kg ha - 1 for first and second harvests, respectively. Herbage dry matter digestibility both pre- and post-grazing was similar ( P  > 0.05) for the two systems, whereas herbage crude protein concentrations were generally significantly lower for the EXT than the INT system. There was no difference ( P  > 0.05) between the Systems in cow live weight, body condition score or their changes or in calf live weight gain from birth to weaning. Post-weaning, live weight gain, slaughter weight, carcass weight, kill-out proportion, estimated carcass gain, carcass conformation score or carcass fat score did not differ ( P  > 0.05) between the systems for heifer, steer or bull progeny. It can be concluded that similar animal performance levels can be expected in an extensive grassland-based suckler calf-to-beef system compatible with the EU, Rural Environmental Protection Scheme as that attained in a more intensive System comprising of both a moderately high SR (~ 1.25 higher) and fertiliser N application (~ 2.1 higher)., (Copyright © 2008 Elsevier B.V. All rights reserved.)