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    Multifunctionality of temperate alley-cropping agroforestry outperforms open cropland and grassland
    (2023-01-24) Veldkamp, Edzo; Schmidt, Marcus; Markwitz, Christian; Beule, Lukas; Beushel, René; Biertümpfel, Andrea; Bischel, Xenia; Duan, Xiaohong; Gerjets, Rowena; Göbel, Leonie; Graß, Rüdiger; Guerra, Victor; Heinlein, Florian; Komainda, Martin; Langhof, Maren; Luo, Jie; Potthoff, Martin; van Ramshorst, Justus G. V.; Rudolf, Carolin; Seserman, Diana-Maria; Shao, Guodong; Siebieke, Lukas; Svoboda, Nikolai; Swieter, Anita; Carminati, Andrea; Freese, Dirk; Graf, Torsten; Greef, Jörg M.; Isselstein, Johannes; Jansen, Martin; Karlovsky, Petr; Knohl, Alexander; Lamersdorf, Norbert; Priesack, Eckart; Wachendorf, Christine; Wachendorf, Michael; Corre, Marife D.
    Intensively managed open croplands are highly productive but often have deleterious environmental impacts. Temperate agroforestry potentially improves ecosystem functions, although comprehensive analysis is lacking. Here, we measured primary data on 47 indicators of seven ecosystem functions in croplands and 16 indicators of four ecosystem functions in grasslands to assess how alley-cropping agroforestry performs compared to open cropland and grassland. Carbon sequestration, habitat for soil biological activity, and wind erosion resistance improved for cropland agroforestry (P ≤ 0.03) whereas only carbon sequestration improved for grassland agroforestry (P < 0.01). In cropland agroforestry, soil nutrient cycling, soil greenhouse gas abatement, and water regulation did not improve, due to customary high fertilization rates. Alley-cropping agroforestry increased multifunctionality, compared to open croplands. To ameliorate the environmental benefits of agroforestry, more efficient use of nutrients is required. Financial incentives should focus on conversion of open croplands to alley-cropping agroforestry and incorporate fertilizer management.
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    Farmer managed natural regeneration in Niger: the state of knowledge
    (Tropenbos International, 2023) Abasse, Tougiani; Massaoudou, Moussa; Ribiou, Habou; Idrissa, Soumana; Iro, Dan Guimbo
    Summary: Faced with environmental degradation and strong land pressure, farmers in densely populated areas and especially in south-central Niger, have intensified their agricultural production systems. They have done so by increasing the number of trees and shrubs on their fields, and thus have created new agroforestry parklands whose scale in – the regions of Zinder, Maradi and Tahoua is about 5 million hectares (Cotillon et al., 2021). This scale of regreening is not based on tree planting. Rather, since the mid-1980s farmers have protected and managed the natural regeneration of trees and shrubs on their croplands. Many studies show that farmer managed natural regeneration (FMNR), has increased crop yields from 31 to 350 kg/ha in some studies and provided family food security, even in drought years. But cereal yields still remain low and will not be sufficient to feed a rapidly growing population. Studies also show that through the sale of fuelwood and service wood, FMNR increases the income of all social categories, even the vulnerable and very vulnerable (men, women and youth). The pruning of trees in the fields has also reduced the distances travelled by women to collect fuelwood. FMNR has also increased the availability of browse fodder to farmers and agropastoralists, with households practising FMNR harvesting 30-45 kg of browse per day. Economists have not yet been able to express the multiple impacts in monetary terms, but studies on the costs and benefits of FMNR all indicate that it is economically rational to invest resources in this practise (4.6). The costs are modest (no equipment and little labour), and the benefits are substantial. As a consequence, tree cover has been sustained without external incentives (e.g. food or cash-for-work), an outcome that distinguishes FMNR from large-scale tree planting projects where farmers’ stewardship ended when the external incentives ended. Agroforestry landscapes are being created at scale due to decisions made by a few hundred thousand individual farmers. A study comparing tree densities in the south-central regions found that on 2% of the area there was a slight decrease in densities between 2005 and 2014, but on 23% there was a significant increase during the same period (Cotillon et al., 2021). Increasing the number of trees and shrubs per hectare has increased litter production. This improves the soil structure and allows greater quantities of water to be stored. However, the addition of litter also contributes to improving soil fertility. Several studies have shown that trees can significantly improve the chemical fertility of soils as well as set the stage for greater intensification through judicious use of mineral fertilizer. Certain species, which often dominate regeneration such as Piliostigma reticulatum, Guiera senegalensis and Combretum glutinosum have a positive impact on the content of chemical elements (carbon, nitrogen and available phosphorus). There is not yet sufficient data on the amount of carbon sequestered by agroforestry parklands in Niger, but it is certainly at least 30 million tonnes – (5 million hectares multiplied by an average of 6 tonnes per hectare). There are data on carbon stocks in the above-ground part of trees for some species (table 8) but not on the amount of carbon in root systems, which in semi-arid areas – can be as substantial as the above-ground stock. FMNR has enabled village communities to better adapt to climate change and build resilience. For example, even if crops fail, farmers can cut some trees and sell them at the market as fuelwood or service wood, which provides revenue to buy grain. FMNR also has a positive impact on crop yields, even in years of poor rainfall. A study showed that in 2011 (a drought year), the department of Kantché (Zinder Region) produced a cereal surplus of almost 13,000 tonnes. This department is characterised by a high population density (over 100 people per hectare), but also by high tree densities. Since the late 1980s, farmers began to perceive that they had a right to the trees on their own farms. This perception led to increased participation of local communities in the management of their natural resources, which was reinforced by the state’s decentralisation policy. Thus forestry policy has evolved from the exclusive management of trees by the state (1960-1980) to a presidential decree issued on 30 July, 2020, which recognises that planted or regenerated trees belong to the producer. This will help encourage farmers to invest more voluntarily in trees on their fields, and will improve the future prospects of young people.
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    Agronomic performance of soybean and sorghum in a short rotation poplar coppice alley-cropping system under Mediterranean conditions
    (Springer Nature, 2023-04-07) Mantino, Alberto; Pecchioni, Giovanni; Tozzini, Cristiano; Mele, Marcello; Ragaglini, Giorgio
    The transition from conventional arable towards silvoarable systems can increase the delivery of ecosystem services. Nevertheless, the assessment of crop yield under agroforestry condition is crucial to evaluate of the reliability of these systems and to increase the knowledge base needed to support their design. Although the feasibility of poplar short rotation coppice (SRC) silvoarable alley-cropping systems has been widely investigated, few studies have addressed the agronomic response of crops intercropped with poplar SRC in narrow alleys, especially in Mediterranean environments. Thus, this paper treats the effects of SRC poplar rows on soybean and sorghum productivity in a 2-year rotation implemented in an alley-cropping system. A field experiment was carried out in 2018 and 2019 with the objective of measuring and evaluating effects of light availability variation, as affected by the growing rate of 2-year coppice cycle poplar SRC rows, and the soil characteristics on soybean-sorghum and sorghum–soybean rotations. Above-ground biomass, grain yield and crops residue showed a significant reduction in the tree–crop interface up to 74% and sorghum proved to be less tolerant to light reduction compared to soybean. Our results demonstrated that light is the most important factor for sorghum cultivation, despite grain yield was also influenced by the soil characteristics such as pH, while soybean is affected also by soil moisture and water retention capacity. The design of crop rotation in an SRC-based agroforestry system needs to consider the different agronomic performance of different crops and the harvest cycle of tree rows.
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    In a nutshell: exploring single tree parameters and above-ground carbon sequestration potential of common walnut (Juglans regia L.) in agroforestry systems
    (Springer Nature, 2023-04-08) Schindler, Zoe; Morhart, Christopher; Sheppard, Jonathan P.; Frey, Julian; Seifert, Thomas
    Although agroforestry systems (AFS) provide numerous ecosystem services and are a recognized strategy for climate change mitigation and adaptation, knowledge on the woody component is lacking. Single tree data could improve planning, management and optimization of AFS. One tree species which is of great interest due to its valuable timber and non-timber products is walnut (Juglans regia L.). We used terrestrial laser scanning data to fit quantitative structure models (QSMs) for 65 walnut trees in AFS with diameter at breast height (DBH) ranging from 1 to 77 cm. Based on the QSMs, volumetric information as well as height and crown parameters were derived. By combining the volumetric data with bark and wood density followed by carbon and nutrient concentration, whole tree biomass, nutrient and carbon content were derived. To enable the application of our results, we modeled allometric relationships based on the DBH. The maximum crown projection area of a tree was more than 340 m2, the maximum leafless above-ground dry biomass was 7.4 t and the maximum amount of stored carbon was 3.6 t (in metric tons). A modelled AFS comprising 15 trees per hectare with a target DBH of 60 cm projects at the end of its 60-year rotation period an above-ground tree volume of more than 100 m3, about 60 t of dry biomass and roughly 30 t of sequestered carbon. By producing allometric functions, we provide much needed information for small-scale modelling of AFS.
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    Orchard meadows: consumer perception and communication of a traditional agroforestry system in Germany
    (Springer Nature, 2023-03-23) Philipp, Sophia M.; Zander, Katrin
    Europe has a large variety of historic cultural agroforestry systems which provide numerous ecosystem services. Traditional agroforestry landscapes are characterized by a high level of biodiversity, but they lack an economic basis due to considerable time and financial effort required for cultivation, maintenance, and harvesting. Orchard meadows (OM) are a typical example for agroforestry systems. They combine large fruit trees with undercropping or livestock raising. This study investigates consumer knowledge and preferences for OM products and the possibilities of improved communication to increase consumer demand. Focus groups were conducted with German consumers. The results demonstrate that consumers have a very positive perception of OM juice in terms of taste, local production, health, and environmental benefits. In order to increase the demand for OM juice, communication with consumers needs to be improved by highlighting these positive attributes.