How does Life Cycle Assessment capture the environmental impacts of agroforestry? A systematic review.

In this paper, a systematic review approach was used to evaluate how environmental Life Cycle Assessment (LCA) has been applied in agroforestry in the context of food systems. This review was used as the basis for discussing methodological issues in the LCA framework for agroforestry systems (AFS) and relevant environmental outcomes in the agroforestry literature. A total of 32 LCAs in 17 countries identified in four databases and spanning a decade form the basis for this paper. Studies were selected based on pre-defined inclusion criteria and followed established guidelines and a review protocol. Qualitative data were extracted and categorized into multiple themes. Results were quantitatively synthesized for the four phases of the LCA for each individual agroforestry practice (i.e., based on its structural composition). Results showed that around half of the selected studies are located in tropical climates, the rest being in temperate climates, predominantly in Southern Europe. Studies primarily used a mass functional unit and rarely included post-farm gate system boundaries. Almost half of the studies account for multifunctionality, and most allocation methods were based on physical properties. Climate change had the greatest coverage from all impact categories with some variations within milk, meat, and crop production systems. Methodological issues were related to limited system boundaries, few impact categories, and differing functional units and multifunctionality approaches. The identified effects of AFS on biodiversity, climate change mitigation, water, soil, pollination, and pest and disease were only partially documented or not analyzed in the LCA studies or the LCA framework. Gaps in knowledge and limitations of the present review were discussed. Further methodological improvements remain necessary to determine the net environmental effects of food products resulting from individual AFS, especially within the area of multifunctionality, carbon sequestration, and biodiversity.

Forage Consumption and Its Effects on the Performance of Growing Swine-Discussed in Relation to European Wild Boar (Sus scrofa L.) in Semi-Extensive Systems: A Review.

Due to its distinct properties, wild boar meat is considered a highly desirable consumer product, in a market that is expanding. Outdoor production is also favoured by consumers who value animal welfare and environmental sustainability when choosing meat products. There is evidence that farms that include pasture for grazing typically have reduced feeding costs. Such production systems can also be more environmentally sustainable as the input (pasture) is inedible to humans, compared to conventional indoor systems, which use human-edible feeds (e.g., soya). However, some wild boar farms have performed poorly compared to those rearing other swine such as hybrid wild boar and domestic pigs. Diet is central to all livestock production and is likely a significant influencing factor of wild boar performance, both in terms of forage consumption and nutritional composition. Other factors may also influence performance, such as weather, behaviour and grazing management. Wild boar production systems hold their own intrinsic value in a growing marketplace. However, information gathered through the study of wild boar has external applications in informing outdoor domestic pig production systems to encourage the use of pasture as part of the habitat of domestic pigs.

Effect of poplar trees on nitrogen and water balance in outdoor pig production - A case study in Denmark.

Nitrate leaching from outdoor pig production is a long-standing environmental problem for surface and groundwater pollution. In this study, the effects of inclusion of poplar trees in paddocks for lactating sows on nitrogen (N) balances were studied for an organic pig farm in Denmark. Vegetation conditions, soil water and nitrate dynamics were measured in poplar and grass zones of paddocks belonging to main treatments: access to trees (AT), no access to trees (NAT) and a control without trees (NT), during the hydrological year April 2015 to April 2016. Soil water drainage for each zone, simulated by two simulation models (CoupModel and Daisy), was used to estimate nitrate leaching from the zones in each paddock. N balances (input minus output) for the treatments were computed and compared. The results showed that, in terms of annual water balance and regardless of treatment, simulated evapotranspiration of poplar was 560-569 and 489-498 mm for CoupModel and Daisy, respectively, and corresponding evapotranspiration of grass-clover was 250 and 400 mm, against precipitation of 1076 mm. Simulated drainage below the root zone varied as 620-723 mm for Daisy and 568-958 mm for CoupModel, the higher end of the latter being probably overestimated. Annual nitrate leaching ranged from 32 kg N ha-1 in the poplar zone of NAT up to 289 kg N ha-1 in the control grass zone of NT. The poplar zone showed significantly lower nitrate leaching, by 75-80%, compared to the grass zone. For the control NT treatment, nitrate leaching was approximately 50% higher in the grass zone closest to the hut compared to the grass zone further away. NT treatment also had the largest surface N balance of 468 kg N ha-1 compared to 436 and 397 kg N ha-1 for AT and NAT, respectively. When N losses by leaching and volatilisation were included, soil N balances were 118, 157 and 113 kg N ha-1 for AT, NAT and NT, respectively. Overall, the two simulation models were found useful tools for analyses of water balance for complex agroforestry systems. The findings collectively suggest that it is possible to decrease nitrate leaching from outdoor pig production on sandy soils by inclusion of poplar trees. Additional measures are nevertheless needed to reduce N losses on a mean area basis in paddocks with 20% tree cover.

Increased Foraging in Outdoor Organic Pig Production-Modeling Environmental Consequences.

Consumers' motivations for buying organic products include a wish of acquiring healthy, environmentally friendly products from production systems that also ensure a high level of animal welfare. However, the current Danish organic pig production faces important challenges regarding environmental impact of the system. High ammonia emissions arise from outdoor concrete areas with growing pigs and sows on pasture possess an increased risk of nitrogen (N) leaching. Direct foraging in the range area is suggested as a way to improve the nutrient efficiency at farm level and to support a more natural behavior of the pig. Thus, by modeling, we investigated the environmental consequences of two alternative scenarios with growing pigs foraging in the range area and different levels of crops available for foraging-grass-clover or a combination of Jerusalem artichokes and lucerne. It was possible to have growing pigs on free-range without increasing N leaching compared to the current practice. The alternative system with Jerusalem artichokes and lucerne (high integration of forage) showed the lowest carbon foot print with 3.12 CO2 eq kg-1 live weight pig compared to the current Danish pasture based system with 3.69 kg CO2 eq kg-1 live weight pig. Due to positive impact on soil carbon sequestration, the second alternative system based on grass-clover (low integration of forage) showed a similar carbon foot print compared to current practice with 3.68 kg CO2 eq kg-1 live weight pig. It is concluded that in practice there is room for development of organic farming systems where direct foraging plays a central role.

Herd and sow-related risk factors for mortality in sows in group-housed systems.

Mortality of sows is a major problem for pig production worldwide. In this study, we used hierarchical multivariable logistic analyses to investigate different risk factors for mortality at the sow and herd level in herds with group-housed pregnant sows. Data included 3652 pregnant and 1266 lactating sows from 34 sow herds. A clinical examination for 16 clinical signs was carried out for each sow, and information about 16 herd related factors was obtained by interviews. Farm records were used to obtain information about whether or not sows died suddenly or were euthanized within 3 months after the clinical examination. Factors increasing the risk of sow mortality in the gestation unit were solid pen floors (OR=1.87), presence of vulva bites (OR=1.73) and unwillingness to stand when approached (OR=1.62). Factors increasing the risk of sow mortality in the lactation unit were pale vulva color (OR=12.69), body leanness (OR=4.11), and presence of shoulder ulcers (OR=2.89). The estimated between herd variation was small. Thus, the findings for the sow level variables may be generally applicable for sows in herds with group housed systems.