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Despite the extensive amount of evidence in the literature regarding the benefits of agroforestry systems including carbon sequestration, soil erosion reduction, climate change resilience, biodiversity conservation and other ecosystem services, the adoption of agroforestry practices presents several barriers for farmers and other stakeholders, thus requiring comprehensive examination from the scientific community. We performed a systematic literature review following the methodology described in the PRISMA framework, to provide a novel comprehensive and systematic overview of what is present in the literature regarding the obstacles stakeholders perceive with regards to agroforestry adoption, gathered through participatory research methods, which are methodologies that engage stakeholders in the research process. In this work, we highlighted and categorized 31 obstacles that stakeholders around the globe perceive according to the examined literature (n = 90) with regards to agroforestry adoption, pertaining to i) technical-agronomic, ii) socio-economic and iii) policy-legislative aspects. We produced a consultable database of the examined literature presenting the extracted and categorized data including 1) Region of interest; 2) Investigated agroforestry system; 3) Methodologies utilized in the papers; 4) Number, gender ratio and type of stakeholders; 5) Main relevant obstacles found in the paper. We highlighted the five most frequently encountered issues i) the availability or quality of knowledge or experience on technical and agronomic matters, or knowledge diffusion necessary to implement or maintain agroforestry systems ii) the perceived socio-economic issue related to the market, marketing of agroforestry products, supply chain or jobs in agroforestry; iii) issues related to the amount of labor or time necessary to implement or maintain agroforestry systems; iv) issues related to the upfront economic investment necessary to establish an agroforestry system and availability of capital; and v) issues related to the availability of technical support necessary to implement or maintain agroforestry systems. [ABSTRACT FROM AUTHOR]

The livestock sector constitutes 14.5% of global green-house gas (GHG) emissions and soil and water pollution due to nitrogen excretion. Methane and nitrogen excretions in ruminants can be mitigated by specific feeding strategies, and tannins reduce methanogenesis and ammonia syntheses. In our study, two kinds of condensed tannins (Mimosa and Gambier) and two kinds of hydrolysable tannins (Chestnut and Tara) were added (4 g/100 g DM) to a basal feed (barley: 48 g/100 g DM, wheat bran: 23 g/100 g DM, dehydrated alfalfa hay:15 g/100 g DM, soybean meal: 10 g/100 g DM and molasses: 2 g/100 g DM), inoculated with rumen fluid and fermented for 24 h. The methane, ammonia, fatty acid and plasmalogen lipid profile were determined. The results confirmed that tannins are an important family of heterogeneous compounds whose effect on rumen metabolism is strongly linked to their different characteristics. Chestnut tannin extract was shown to be a good compromise. It improved the sustainability of ruminant rearing by decreasing methanogenesis (control feed 0.159 vs chestnut feed 0.137 mmol/L rumen fluid; p = .0326), ammonia production (control feed 248 vs chestnut feed 179 mg/L rumen fluid; p

Cropping among trees with perennial legumes is one option for increasing agro-ecosystem services, such as improving the nitrogen supply and increasing soil protection by herbaceous vegetation. Moreover, cropping under the canopy of olive trees should diversify the farm production, compared to the traditional fallow management. Among perennial legumes, alfalfa (Medicago sativa L.) produces abundant biomass under Mediterranean rainfed condition. Based on this, a two-year field experiment was implemented in southern Tuscany in a rainfed olive orchard to test the competition for light effects on alfalfa biomass production and nutritive value. Light availability under the tree canopy was measured by hemispherical photos. In both years, the alfalfa yield of under-canopy varied according to the tree presence. A significant relationship between biomass production and light availability was recorded. The nutritive value of under-canopy alfalfa was similar to that of the open-grown alfalfa. However, same significant differences did however occur, between shaded and sole crop. When differences were found, under-canopy herbage was characterised by a higher content of crude protein and a lower content of fibre with respect to open-grown. In a hilly silvoarable olive orchard, alfalfa biomass accumulation was reduced mainly due to scarce light availability, therefore tree management such as pruning and plantation layout can enhance the herbage productivity. Studying shade tolerant forage legumes in order to enhance the yield and nutritive value of herbage production in rainfed agroforestry systems is essential.

Agroforestry is indicated as a farming practice suited to enhance ecosystem services generated by cropping systems. However, farmers are often reluctant to implement agroforestry systems due to the potential yield loss of crops. In a field trial, soybean was intercropped with poplar short-rotation-coppice rows in an alley-cropping system with 13.5 m wide alleys, in order to assess the effect of tree presence on soybean yield and quality. The light availability (LA) was significantly affected by the tree presence, with an increasing effect along the season due to tree growth, being at its lowest in the tree−crop interface positions (West and East). Significant effects of the tree-distance and LA were registered on soybean yield, with the highest reduction of soybean yield in the West (−78%) and East (−35%) positions. Crude fat content in soybean grain did not vary among positions in the alley, while crude protein content was the lowest in the most shaded position (West −8% than the highest value). The assessment of spatial variability among plots of measured soil characteristics highlighted no significant effect of pedological conditions upon soybean yield. Thus, in our study, the LA effect was more important than soil characteristics in determining a detrimental effect of competition for resources between soybean and poplar. Conversely, soybean quality was affected by soil characteristics, since crude fat significantly correlated with soil nutrients, pH, soil organic matter and soil texture.

The livestock sector constitutes 14.5% of global green-house gas (GHG) emissions and soil and water pollution due to nitrogen excretion. Methane and nitrogen excretions in ruminants can be mitigated by specific feeding strategies, and tannins reduce methanogenesis and ammonia syntheses. In our study, two kinds of condensed tannins (Mimosa and Gambier) and two kinds of hydrolysable tannins (Chestnut and Tara) were added (4 g/100 g DM) to a basal feed (barley: 48 g/100 g DM, wheat bran: 23 g/100 g DM, dehydrated alfalfa hay:15 g/100 g DM, soybean meal: 10 g/100 g DM and molasses: 2 g/100 g DM), inoculated with rumen fluid and fermented for 24 h. The methane, ammonia, fatty acid and plasmalogen lipid profile were determined. The results confirmed that tannins are an important family of heterogeneous compounds whose effect on rumen metabolism is strongly linked to their different characteristics. Chestnut tannin extract was shown to be a good compromise. It improved the sustainability of ruminant rearing by decreasing methanogenesis (control feed 0.159 vs chestnut feed 0.137 mmol/L rumen fluid; p =.0326), ammonia production (control feed 248 vs chestnut feed 179 mg/L rumen fluid; p <.0001) and enhancing acetate synthesis (production rate: chestnut 68.68% vs 49.64% of control). Tannin extracts from trees and shrubs can be used to modulate rumen fermentation. The positive effect of chestnut tannin extract was demonstrated on methane and ammonia production. Tannins showed no protective action on C18:2 trans 11. [ABSTRACT FROM AUTHOR]

The successful promotion of agroforestry in Italy depends on both a recognition of tradition and the opportunities for innovation. In Italy, agroforestry has traditionally been a key component of landscape management. Complex systems, based on the integration among crops–livestock–fruit/forest trees, provided a wide variety of products (e.g. food, feed, fibers, fuelwood and timber) and other ecosystem services (e.g. soil erosion control and biodiversity preservation). Silvopastoral systems have been used for centuries and are still managed in marginal areas. The integration of fruits trees (in primis olive trees) with crops and grazing was widely practiced and is still profitable. Coltura promiscua was historically developed integrating fruit and forest trees and particularly multifunctional trees (e.g. Juglans regia L. and Prunus avium L.) to support vines and intercrops. Building on recent research, projects have also focused on innovation in agroforestry. The adoption of shade tolerant forage species and crops has been studied in silvopastoral and olive systems. Silvopastoral systems can significantly offset the greenhouse gas emissions produced by livestock and shield grazing animals from "heat waves". Integration of fast growing timber trees (like Populus) in arable systems can help reverse the decline in plantation forestry in Italy. Finally, the constraints imposed by the EU agricultural policy, especially the prevalent provisions for monocrops severely limiting the introduction of innovative agroforestry approaches, are discussed. New political measures and certification actions are strongly required. [ABSTRACT FROM AUTHOR]

Cropping among trees with perennial legumes is one option for increasing agro-ecosystem services, such as improving the nitrogen supply and increasing soil protection by herbaceous vegetation. Moreover, cropping under the canopy of olive trees should diversify the farm production, compared to the traditional fallow management. Among perennial legumes, alfalfa (Medicago sativa L.) produces abundant biomass under Mediterranean rainfed condition. Based on this, a two-year field experiment was implemented in southern Tuscany in a rainfed olive orchard to test the competition for light effects on alfalfa biomass production and nutritive value. Light availability under the tree canopy was measured by hemispherical photos. In both years, the alfalfa yield of under-canopy varied according to the tree presence. A significant relationship between biomass production and light availability was recorded. The nutritive value of under-canopy alfalfa was similar to that of the open-grown alfalfa. However, same significant differences did however occur, between shaded and sole crop. When differences were found, under-canopy herbage was characterised by a higher content of crude protein and a lower content of fibre with respect to open-grown. In a hilly silvoarable olive orchard, alfalfa biomass accumulation was reduced mainly due to scarce light availability, therefore tree management such as pruning and plantation layout can enhance the herbage productivity. Studying shade tolerant forage legumes in order to enhance the yield and nutritive value of herbage production in rainfed agroforestry systems is essential. [ABSTRACT FROM AUTHOR]

Poplar (Populus L. spp.) Short Rotation Coppice systems (SRCs) for bioenergy production are being converted back to arable land. Transitioning to Alley Cropping Systems (ACSs) could be a suitable strategy for integrating former tree rows and arable crops. A field trial (Pisa, Central Italy) was set up with the aim of assessing the C storage of an ACS system based on hybrid poplar and sorghum (Sorghum bicolor L. Moench) and comparing it with that of an SRC cultivation system. The carbon budget at the agroecosystem scale was assessed in the first year of the transition using the net biome production (NBP) approach with a simplified method. The overall NBP for the SRC was positive (96 ± 40 g C m−2 year−1), highlighting that the system was a net carbon sink (i.e., NBP > 0). However, the ACS registered a net C loss (i.e., NBP < 0), since the NBP was −93 ± 56 g C m−2 year−1. In the first year of the transition, converting the SRC into an ACS counteracted the potential beneficial effect of C storage in tree belowground biomass due to the high heterotrophic respiration rate recorded in the ACS, which was fostered by the incorporation of residues and tillage disturbance in the alley. Additional years of heterotrophic respiration measurements could allow for an estimate of the speed and extent of C losses. [ABSTRACT FROM AUTHOR]

Agroforestry is indicated as a farming practice suited to enhance ecosystem services generated by cropping systems. However, farmers are often reluctant to implement agroforestry systems due to the potential yield loss of crops. In a field trial, soybean was intercropped with poplar short-rotation-coppice rows in an alley-cropping system with 13.5 m wide alleys, in order to assess the effect of tree presence on soybean yield and quality. The light availability (LA) was significantly affected by the tree presence, with an increasing effect along the season due to tree growth, being at its lowest in the tree–crop interface positions (West and East). Significant effects of the tree-distance and LA were registered on soybean yield, with the highest reduction of soybean yield in the West (−78%) and East (−35%) positions. Crude fat content in soybean grain did not vary among positions in the alley, while crude protein content was the lowest in the most shaded position (West −8% than the highest value). The assessment of spatial variability among plots of measured soil characteristics highlighted no significant effect of pedological conditions upon soybean yield. Thus, in our study, the LA effect was more important than soil characteristics in determining a detrimental effect of competition for resources between soybean and poplar. Conversely, soybean quality was affected by soil characteristics, since crude fat significantly correlated with soil nutrients, pH, soil organic matter and soil texture. [ABSTRACT FROM AUTHOR]