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Landscape composition may influence biodiversity and ecosystem services in agricultural fields. Hitherto, most studies have focused on annual crops and the available information on the impacts of landscape structure in orchards is sparse. In this study, we evaluated the effects of pesticide use as cumulative toxicity on pest and predatory beetle (Coleoptera) assemblages in the canopy of apple orchards surrounded by different proportion of semi-natural vegetation, crop fields and settlements in Hungary. Laboratory data suggest that increasing pesticide toxicity negatively affects predators (coccinellids), but we did not find such a pattern. Supposedly, the effect of pesticides was masked by the continuous recolonisation of orchards from the surrounding landscape. On the contrary, for the less mobile pest species [ Anthonomus pomorum , Phyllobius oblongus (Curculionidae)] we did find a decline in abundance along the gradient of increasing pesticide toxicity. Landscape composition around the orchards significantly influenced the abundance of predatory, fungivorous and tourist species, but had no effect on pests. Contrary to expectations, however, semi-natural habitats had a minor effect compared to arable fields, orchards and settlements which habitat types had various effects on the abundance of different coleopteran groups and species. For example, Harmonia axyridis (Coccinellidae) abundance was positively affected by its overwintering sites, i.e. human settlements in spring, semi-natural forests in summer, and arable fields in autumn. The mass immigration of other predatory, fungivorous and tourist species from the surrounding arable fields into the orchards started from July with senescence and harvesting of arable crops. These results suggest that arable fields, other orchards and settlements might be more important sources of colonisation for natural enemies in orchards than certain semi-natural habitats. [ABSTRACT FROM AUTHOR]

Land conversion from natural to managed ecosystems, while necessary for food production, continues to occur at high rates with significant water impacts. Further, increased rainfall variability exposes agricultural systems to impacts from flood and drought events. In many regions, water limitations are overcome through technological approaches such as irrigation and tile drainage, which may not be sustainable in the long term. A more sustainable approach to combat episodes of floods and droughts is to increase soil water storage and the overall green water efficiency of agroecosystems. Agricultural practices that promote “continuous living cover,” such as perennial grasses, agroforestry and cover crops, can improve water management relative to annual crop systems. Such practices ensure living roots in agricultural systems throughout the year and offer an approach to agroecosystem design that mimics ecological dynamics of native perennial vegetation. We review how these practices have been shown to improve elements of the water balance in a range of environments, with an emphasis on increased soil hydrologic function. A specific focus on the agriculturally intensive state of Iowa provides insight into how land use centered on agroecological principles affords greater water resilience, for individual farms as well as for broader community and ecosystem health. [ABSTRACT FROM AUTHOR]

Perennial grains have been proposed to stabilise fragile lands while contributing grain and grazing in mixed farming systems. Genotype by environment (GxE) interactions for grain yield were investigated in 22 perennial rice ( Oryza sativa L./ Oryza longistaminata ) derivatives over four successive growing seasons at three sites in Yunnan in southern China and one site in Lao PDR. The GxE interaction accounted for 25.7% of the total sum of squares, with environment and genotype responsible for 57.4% and 16.9%, respectively. Cluster analysis identified seven environment and six genotype groups, which accounted for 55.6% of the GxE sum of squares. Principal component axes 1, 2 and 3 accounted for 42.3%, 19.1% and 16.5% of the GxE-SS, respectively, with PCA1 indicating yield potential, PCA2 delay in phenology under environmental stress, and PCA3 ratoon percentage. Environment groups differed in mean temperature, whether dry season or wet season, and occurrence of environmental stresses, such as periods of low minimum temperature or periods of rainfall deficit. Genotype groups differed in adaptation to these diverse environments. For genotype groups, G5 (PR23) was highest-yielding and broadly adapted across environments, while G1 (line 188, both 137s, both 139s, both 147s) was low-yielding and poorly adapted. Other genotype groups showed preferential adaptation: G3 (lines 60, 251, 264, Bt69, Bt71) to Simao/Dry Season (E3 and E4), G4 (lines 75, 243, 246, 249, 255) to Menglian/Wet Season (E1 and E2), G2 (line TZ) to Jing Hong 2013 (E7), and G6 (lines 56, 59, 214) to Jing Hong 2102 and Na Pok (E6 and E5). The results imply that regrowth success and maintenance of spikelet fertility over regrowth cycles are important for adaptation of perennial rice, especially to low minimum temperature at higher altitude and rainfall deficit at lower altitude, and future breeding programmes in perennial rice should address these environmental stresses. The high yield and broad adaptation of PR23 (G5) over environments makes it a prime candidate for release to stabilise fragile lands in the humid and subhumid tropics, while contributing grain and forage in mixed-farming systems. [ABSTRACT FROM AUTHOR]

The carbon footprint (CF) evaluates the overall amount of greenhouse gas emissions and removals associated with a product or activity across its life cycle. Today, the CF assessment has the potential to be a key measurement for increasing sustainable agricultural production. In addition, the export-oriented fruit sector has been challenged to quantify and reduce their CF. Worldwide there are scant peer-review studies that examine the CF of stone fruits (Prunus genus). The scarcity is most evident in sweet cherries, which is the third most exported stone fruit in the world in terms of value (after almonds and peaches). Chile is the largest southern hemisphere producer and exporter of sweet cherry fruit. Within this context, the present study is one of the first assessments of the CF of conventional sweet cherry production. This work considers Chilean agricultural practices and identifies key influencing factors (hotspots). It takes into account the following agricultural inputs: mineral fertilizers, pesticides, diesel consumption for agricultural operations, machinery, and electricity for irrigation. The results indicate that the average CF of the Chilean sweet cherry production is 0.41 kg CO2-eq/kg of harvested fruit, with a 95% confidence interval between 0.36 and 0.47 kg CO2-eq/kg. This value is higher than those for other stone fruits reported by the literature. Diesel and fertilizers are the most important contributors to the CF of sweet cherry cultivation. Improvement scenarios are evaluated for the hotspots in order to reduce greenhouse gas emissions from the production of this fruit. This study provides quantitative environmental criteria associated with global warming concerns to the stakeholders in the fruit sector and to the agricultural policymakers. [ABSTRACT FROM AUTHOR]

As bioenergy plants, short rotation woody crops (SRWC) feature high biomass productivity and provide positive external effects, such as reduced soil erosion, increased soil life, and reduced nitrate leaching. However, they are not widespread in intensive cropping systems due to long investment periods and perceived economic disadvantages (low profitability and high risk). Nevertheless, the perceived uncertainty as the main barrier of adoption has not been addressed sufficiently, since the economic risk of SRWC has not been quantified and compared with conventional crops extensively. Another shortcoming of recent economic evaluations is that they are based on mutually exclusive comparisons of alternative investments. In fact, SRWC can be considered an asset of agricultural portfolios, whereby diversification effects are expected due to different ecology, products, and markets. To address these shortcomings, we quantified the economic risk of SRWC and conventional crops and applied the Modern Portfolio Theory to evaluate the economic diversification effects of SRWC at the farm level in a low- and a high-yielding study region in Bavaria (Germany). In SRWC-crop comparisons, SRWC showed the lowest economic risk of all crops compared and gross margins which were competitive with most alternative crops. Furthermore, the correlation of the gross margins of SRWC and agricultural crops compared was relatively low. Therefore, the inclusion of SRWC into existing farm production plans offered economic diversification, increasing the profitability at farm scale, while lowering risk. Thus, diversifying cash crop rotations with SRWC is an effective risk-management instrument that can furthermore provide positive external effects. [ABSTRACT FROM AUTHOR]

Balancing weed suppression, beneficial insect conservation, soil quality and profitability is challenging in organic cropping systems due to reliance on soil disturbance for weed control. We hypothesized that the benefits of tillage can be retained while mitigating adverse impacts on soil quality by alternating tillage with practices that can build soil organic matter. We conducted a four-year experiment in central Pennsylvania, USA, to compare four organic feed and forage cropping systems, each differing in tillage, manure management, and cropping strategies. Each system was designed to address baseline soil quality and weed pressure conditions arising from practices implemented during the previous three-year transition period. To assess cumulative system effects, we established a soybean ( Glycine max ) uniformity trial across all systems in year four. Systems that were in perennial forage for 2 years outperformed annual crop-based systems in weed control and beneficial insect conservation, while maintaining overall profitability over the four-year study period. Soybean yields during the uniformity trial were more than 30% greater in systems that had included perennial forages than in systems with only annual crops. Labile soil carbon pools, an indicator of soil quality, were maintained over time in all systems. Our results indicate that soil quality, weed management, beneficial insect conservation, and profitability can be maintained in organic systems when periodic tillage is coupled with perennial forage crops in rotation. [ABSTRACT FROM AUTHOR]

J. Russell Smith (1874–1966), a professor of geography at Columbia University, witnessed the devastation of soil erosion during his extensive travels. He first published his landmark text, Tree Crops, A Permanent Agriculture in 1929, in which he described the value of tree crops for producing food and animal feed on sloping, marginal, and rocky soils as a sustainable alternative to annual crop agriculture less suited to these lands. A cornerstone of his thesis was using wide germplasm collection and plant breeding to improve this largely underutilized and genetically unexploited group of plants to develop locally adapted, high-yielding cultivars for the many climatic zones of North America. Smith proposed an establishment of “Institutes of Mountain Agriculture” to undertake this work. For a variety of reasons, though, his ideas were not implemented to any great degree. However, our growing population’s increasing demands on natural resources and the associated environmental degradation necessitate that Smith’s ideas be revisited. In this review, his concepts, supported by modern scientific understanding and advances, are discussed and expanded upon to emphasize their largely overlooked potential to enhance world food and energy security and environmental sustainability. The discussion leads us to propose that his “institutes” be established worldwide and with an expanded scope of work.

Super high-density (SHD) olive orchards are rapidly expanding since the first plantation was set up in Spain in the 1990s. Because there are no long-term studies characterizing these systems, it is unknown if densities above a certain threshold could trigger competition among fully-grown trees, compromising their development. Over 14 years we have evaluated the performance of the major olive cultivars currently planted in SHD systems (‘Arbequina’, Arbequina IRTA-i·18R, ‘Arbosana’, ‘Fs-17’, and ‘Koroneiki’) and nine SHD designs ranging from 780 to 2254 trees ha-1 for the cultivar ‘Arbequina’. Remarkably, the accumulated fruit and oil production of the five cultivars increased linearly over time. Our data indicated the favorable long-term performance of the evaluated cultivars with an average annual oil production of 2.3 t ha-1. Only ‘Fs-17’ did not perform well to the SHD system in our conditions and it yielded about half (1.2 t ha-1) of the other cultivars. In the density trial for ‘Arbequina’, both fruit and oil accumulated production increased over time as a function of tree density. Thus, the accumulated oil yield ranged from 16.1 t ha-1 for the lowest density (780 trees ha-1) to 29.9 t ha-1 for the highest (2254 trees ha-1). In addition, we note that the accumulated production per surface unit showed a better correlation with the hedgerow length than the tree density. Thus, the current planting designs of SHD olive orchards can be further improved taking this parameter into account. Despite observations that some irregular patterns of crop distribution have arisen, our olive hedgerows are still fully productive after 14 years of planting. This result contradicts previous experiences that showed declines in production seven or eight years after planting due to high vigor, shading, and limited ventilation.

An increasing production of annual bioenergy crops such as maize has led to regional land-use changes, causing further shortages of already scarce floral resources for pollinators. Diversification of energy crop production with flowering crops is discussed as a mitigation strategy. The perennial Silphium perfoliatum, characterized by a flowering period between July and September, represents a promising candidate crop., The present study aimed to investigate the management and landscape conditions under which a cultivation of S. perfoliatum could be an effective measure for pollinator conservation. In this context, hoverflies served as suitable indicators as a result of the different feeding behaviours of adults (floral resources) and larvae (mostly zoophagous or microphagous)., We compared abundance and species richness of adult hoverflies in 15 flowering S. perfoliatum fields in Germany with that in neighbouring habitats (maize fields, ditches/brooks and forest edges) and tested whether the landscape composition influenced local abundance and species richness in S. perfoliatum fields depending on larval feeding type., Only microphagous hoverflies were more abundant in S. perfoliatum fields than in neighbouring habitats, primarily in mid- September. This might be explained by the different activity periods and adaptations to flower traits of the two hoverfly groups. Although the abundance of zoophagous hoverflies was positively influenced by a higher crop diversity, the abundance and species richness of microphagous hoverflies responded positively to higher proportions of semi-natural habitats in the surroundings., Silphium perfoliatum can support certain hoverfly groups when it is harvested late to ensure a flower supply through to September and when semi-natural habitats are maintained in agricultural landscapes. [ABSTRACT FROM AUTHOR]

Ants and termites, as soil engineers, provide many ecosystem services that can be important for the sustainability of agriculture. The aim of this study was to evaluate the impact of land use on ant and termite communities in Colombian savanna landscapes, and to assess whether this impact is associated with the modification of soil physical and chemical properties. Ants and termites were sampled in five different agricultural and semi-natural systems across three regions of the eastern Colombian Llanos: 1) annual crops (maize, soy and rice), 2) rubber plantations, 3) oil palm plantations, 4) improved pastures and 5) semi-natural savannas. A total of 91 ant and 16 termite species were collected. Multivariate analysis revealed that termite communities significantly differed among land uses, but not between regions. Ant communities differed between regions and land uses. Based on between group analyses of termite communities, three groups of land use can be distinguished: one formed by semi-natural savannas and improved pastures, the second by oil palm plantations and annual crops and the third by rubber plantations. General linear models applied separately to each species found 19 significant associations of soil physical or chemical properties, land uses or regions with 15 ant species and 14 significant associations with 6 termite species. Taken together, there is a strong association between land use and ant or termite communities and this influence is likely due to changes in ant and termite habitats resulting from agricultural practices such as tillage, fertilization, and lime addition. These results suggest that annual crops are the most detrimental land use for termites and ants, because their communities are highly sensitive to vegetation cover and agricultural practices such as tillage. Maintaining a high diversity of soil engineers and the ecosystem services they provide likely depends on the maintenance of natural ecosystems in the landscape and the adoption of practices that reduce impacts on soil ecosystem engineers when native ecosystems have been transformed into agricultural systems. [ABSTRACT FROM AUTHOR]

Perennial crops can deliver a wide range of ecosystem services compared to annual crops. Some of these benefits are achieved by lengthening the growing season, which increases the period of crop water and nutrient uptake, pointing to a potential role for perennial systems to mitigate soil nitrous oxide (N2O) emissions. Employing a micrometeorological method, we tested this hypothesis in a 3-year field experiment with a perennial grass-legume mixture and an annual corn monoculture. Given that N2O emissions are strongly dependent on the method of fertilizer application, two manure application options commonly used by farmers for each crop were studied: injection vs. broadcast application for the perennial; fall vs. spring application for the annual. Across the 3 years, lower N2O emissions ( P < 0.001) were measured for the perennial compared to the annual crop, even though annual N2O emissions increased tenfold for the perennial after ploughing. The percentage of N2O lost per unit of fertilizer applied was 3.7, 3.1 and 1.3 times higher for the annual for each consecutive year. Differences in soil organic matter due to the contrasting root systems of these crops are probably a major factor behind the N2O reduction. We found that a specific manure management practice can lead to increases or reductions in annual N2O emissions depending on environmental variables. The number of freeze-thaw cycles during winter and the amount of rainfall after fertilization in spring were key factors. Therefore, general manure management recommendations should be avoided because interannual weather variability has the potential to determine if a specific practice is beneficial or detrimental. The lower N2O emissions of perennial crops deserve further research attention and must be considered in future land-use decisions. Increasing the proportion of perennial crops in agricultural landscapes may provide an overlooked opportunity to regulate N2O emissions. [ABSTRACT FROM AUTHOR]

Enhancing naturally occurring generalist predators can improve pest control. In orchards, canopy-dwelling species are major actors of pest control because pests attack fruits and growing shoots within the canopy. Cheiracanthium mildei, an arboreal spider, is a predator of several important insect pests. We assessed its autumnal occurrence in a set of 61 commercial apple orchards over three consecutive years (2010–2012). We determined the impact of agronomic and land-cover characteristics on C. mildei occurrence at both the local and landscape levels using a random forest analysis and regression trees. This approach highlighted the differential effect of landscape variables according to local orchard pest management. First, the presence of exclusion nets against the codling moth (Cydia pomonella) increased C. mildei occurrence by 59%. Second, landscape variables only influenced C. mildei occurrence in orchards that were not covered by nets. In particular, abandoned orchards increased C. mildei occurrence in orchards not covered by nets and not surrounded by organic orchards. Third, overall, habitats containing trees increased C. mildei abundance in orchards with and without nets, which is consistent with the arboreal habitat of this species. Lastly, the occurrences of C. mildei and of C. pomonella were not related, indicating that the enhancement of C. mildei does not preclude a control of this major pest. [ABSTRACT FROM AUTHOR]

Preserving soils is a major challenge in ensuring sustainable agriculture for the future. Soil erosion by water is a critical issue in the Mediterranean regions and usually occurs when high-erosive precipitation is in temporal association with poor vegetation cover and density. Modelling soil erosion risks over large spatial scales suffers from the scarcity of accurate information on land cover, rainfall erosivity and their intra-annual dynamics. We estimated the soil erosion risk on arable land in a Mediterranean area (Grosseto Province, southern Tuscany, Italy) and investigated its potential reduction as a response to the change in intra-annual distribution of land cover due to the increase of perennial forage crops. A GIS-based (R)USLE model was employed and a scenario analysis was performed by setting criteria for raising the performance of perennial forage crops. Statistical data on agricultural crops provided an insight into current intra-annual land cover dynamics. Rainfall erosivity was computed on the basis of 22-year hourly precipitation data. The model was used to: i) quantify the potential soil losses of arable land in the study area, ii) identify those areas highly affected by erosion risks iii) explore the potential for soil conservation of perennial crops, thereby enabling appropriate preventive measures to be identified. The erosion rates, averaged over an area of about 140’000 ha, are estimated to 33.42 Mg ha −1 y −1 . More than 59% of the study area was subjected to soil losses higher than 11 Mg ha −1 y −1 (from moderate to severe erosion) and the highest rates are estimated for steep inland areas. Arable land with severe soil erosion rates (higher than 33 Mg ha −1 y −1 ) represent about 35% of the whole study area. The risk of soil loss by water erosion in the study area is estimated to be reduced on average by 36% if perennial crops are increased in terms of 35% of the total arable land. The soil erosion data produced compared well with the published local and regional data. This study thus provides useful preliminary information for landscape planning authorities and can be used as a decision support tool in quantifying the implications of management policies. [ABSTRACT FROM AUTHOR]

Behaviour of crops and soils due to non-redressal of spatial variability in soil properties is not expressed uniformly within bigger orchard/field which has been the major triggering factor for not able to break yield barrier through conventional nutrient management strategy. Better response of site specific nutrient management (SSNM) over recommended doses of fertilizers (RDF) including those of farmers’ usual fertilizer practices (FFP) signals a wake-up call to address the fertilizer requirements on the principles of SSNM, if the full potential productivity of perennial crops has to be realized and sustain on any given soil type. The SSNM also warrants to tailor the fertilizer application on the basis of spatial variation in soil fertility and tree canopy size within an orchard/field through variable rate fertilizer application to minimize the gap between actual and potential productivity of crops. Application of geospatial tools like GPS and GIS coupled with DRIS- based nutrient diagnostics has substantially aided in developing rationale of fertilizer use using SSNM concept in crops like citrus, avocado, coconut, olive etc. which could well be expanded to other perennial crops.

Nous essayons dans cet article de fournir les grandes caractéristiques du marché mondial des huiles végétales, avec l’intention tout d’abord de décrire la contribution des oléagineux pérennes et son évolution dans la production et le commerce mondial des huiles, puis de comprendre la nature particulière des risques attachés à ces cultures. À partir de données historiques couvrant la presque totalité du siècle, nous verrons que la situation actuelle est une situation d’incertitude : la part des oléagineux pérennes dans l’échange stagne après avoir connu un cycle de vingt années de croissance, tandis que les deux risques fondamentaux que sont l’exposition aux fluctuations des prix mondiaux (on n’arrache pas ses arbres au gré des baisses de cours) et la rigidité de la productivité du travail (on ne sait pas mécaniser de manière satisfaisante la collecte des fruits) ne trouvent pas de solution satisfaisante. La première partie aborde ces points. Nous reviendrons dans un deuxième temps sur un exemple réussi de couverture du risque, dans le cas de l’huile de palme, avec l’exemple malaysien qui prouvera que des stratégies nationales de gestion de risque peuvent être efficaces, sinon indispensables, et complémentaires du développement d’initiatives privées. Qu’en est-il de l’Afrique et quelle est l’ampleur des risques et des contraintes qu’y rencontrent les cultures oléagineuses pérennes : ce sont les deux questions qui occuperont notre troisième et dernière partie, en réponse desquelles seront décrits la convention de Lomé et ses effets sur la production et le commerce oléagineux sur le continent africain. Nous conclurons sur l’opportunité pour l’Afrique d’augmenter ses parts de marché nationales et internationales à la lumière des éléments apportés dans les trois parties de cet article.

The cultivation of perennial cash crops is fast expanding in the tropics, but for most crops and regions there is very limited understanding about their biodiversity impacts. This is the case of cashew nut cultivation, which is occupying ever larger areas, particularly in West Africa. Here we investigated the impacts of cashew cultivation on biodiversity using butterfly assemblages sampled across a gradient of cashew expansion in Guinea-Bissau (West Africa). The overall species richness and abundance of butterflies were only slightly lower in cashew orchards than in native woodland habitats, but whereas the former were dominated by generalist species, the latter showed a much higher richness and abundance of trophic and habitat specialists. The landscape context significantly affected butterfly assemblages, with reduced richness and abundance of generalist species recorded within woodland habitats in heterogeneous landscapes with low woodland cover. Increases in land cover by cashew cultivation were associated with reduced abundance of specialist species within woodland habitats, and reduced abundance of generalist species within cashew orchards. Overall, our study provides the first evidence that cashew expansion may have serious negative consequences for biodiversity in West Africa, suggesting that this is an unfolding conservation problem that needs to be fully evaluated. Retaining woodland patches within production landscapes might help reducing the negative impacts of cashew expansion on biodiversity. [ABSTRACT FROM AUTHOR]

Bioenergy (i.e., bioheat and bioelectricity) could simultaneously address energy insecurity and climate change. However, bioenergy’s impact on climate change remains incomplete when land use changes (LUC), soil organic carbon (SOC) changes, and the auxiliary energy consumption are not accounted for in the life cycle. Using data collected from Belgian farmers, combined heat and power (CHP) operators, and a life cycle approach, we compared 40 bioenergy pathways to a fossil-fuel CHP system. Bioenergy required between 0.024 and 0.204 MJ (0.86 MJ th + 0.14 MJ el ) − 1 , and the estimated energy ratio (energy output-to-input ratio) ranged from 5 to 42. SOC loss increased the greenhouse gas (GHG) emissions of residue based bioenergy. On average, the iLUC represented ∼67% of the total GHG emissions of bioenergy from perennial energy crops. However, the net LUC (i.e., dLUC + iLUC) effects substantially reduced the GHG emissions incurred during all phases of bioenergy production from perennial crops, turning most pathways based on energy crops to GHG sinks. Relative to fossil-fuel based CHP all bioenergy pathways reduced GHG emissions by 8–114%. Fluidized bed technologies maximize the energy and the GHG benefits of all pathways. The size and the power-to-heat ratio for a given CHP influenced the energy and GHG performance of these bioenergy pathways. Even with the inclusion of LUC, perennial crops had better GHG performance than agricultural and forest residues. Perennial crops have a high potential in the multidimensional approach to increase energy security and to mitigate climate change. The full impacts of bioenergy from these perennial energy crops must, however, be assessed before they can be deployed on a large scale. [ABSTRACT FROM AUTHOR]

Virus diseases of perennial trees and vines have characteristics not amenable to study using small model annual plants. Unique disease symptoms such as graft incompatibilities and stem pitting cause considerable crop losses. Also, viruses in these long-living plants tend to accumulate complex populations of viruses and strains. Considerable progress has been made in understanding the biology and genetics of Citrus tristeza virus (CTV) and in developing it into a tool for crop protection and improvement. The diseases in tree and vine crops have commonalities for which CTV can be used to develop a baseline. The purpose of this review is to provide a necessary background of systems and reagents developed for CTV that can be used for continued progress in this area and to point out the value of the CTV-citrus system in answering important questions on plant-virus interactions and developing new methods for controlling plant diseases. [ABSTRACT FROM AUTHOR]

Understanding how weed communities assemble as a function of biotic and abiotic filters and transform through time has important implications for the sustainable management of agronomic systems. In a three-year study, we evaluated weed community responses to lucerne (Medicago sativa, perennial) vs. continuous spring wheat (Triticum aestivum, annual, CSW) and weed management practices where weeds in the CSW system were managed with three contrasting approaches (herbicide, tillage or sheep grazing). Our results indicated no differences in weed diversity between the perennial and annual crops or across the different management practices in CSW. However, there were differences in weed community composition. Lucerne, with the exception of the establishing year, impeded the growth and reproduction of several annual weeds, including Amaranthus retroflexus, Thlaspi arvense, Lamium amplexicaule and Chenopodium album, but favoured perennial broad-leaved weeds such as Taraxacum officinale and Cirsium arvense. The replacement of herbicide treatments in pre-plant and post-harvest in CSW with soil tillage or sheep grazing selected for different weed communities beyond the second year of establishment. The weed species driving the differences in CSW systems were Androsace occidentalis, more common in CSW managed chemically; Asperugo procumbens, more common in CSW managed with tillage; and T. officinale and Lactuca serriola, more common in CSW managed with sheep grazing. Understanding how cropping systems modify weed communities is a necessary step to shift from reactive weed control programmes to predictive management strategies. [ABSTRACT FROM AUTHOR]

Wood from short rotation coppices (SRCs) is discussed as bioenergy feedstock with good climate mitigation potential inter alia because soil organic carbon (SOC) might be sequestered by a land-use change (LUC) from cropland to SRC. To test if SOC is generally enhanced by SRC over the long term, we selected the oldest Central European SRC plantations for this study. Following the paired plot approach soils of the 21 SRCs were sampled to 80 cm depth and SOC stocks, C/N ratios, pH and bulk densities were compared to those of adjacent croplands or grasslands. There was no general trend to SOC stock change by SRC establishment on cropland or grassland, but differences were very site specific. The depth distribution of SOC did change. Compared to cropland soils, the SOC density in 0-10 cm was significantly higher under SRC (17 ± 2 in cropland and 21 ± 2 kg C m−3 in SRC). Under SRC established on grassland SOC density in 0-10 cm was significantly lower than under grassland. The change rates of total SOC stocks by LUC from cropland to SRC ranged from −1.3 to 1.4 Mg C ha−1 yr−1 and −0.6 Mg C ha−1 yr−1 to +0.1 Mg C ha−1 yr−1 for LUC from grassland to SRC, respectively. The accumulation of organic carbon in the litter layer was low (0.14 ± 0.08 Mg C ha−1 yr−1). SOC stocks of both cropland and SRC soils were correlated with the clay content. No correlation could be detected between SOC stock change and soil texture or other abiotic factors. In summary, we found no evidence of any general SOC stock change when cropland is converted to SRC and the identification of the factors determining whether carbon may be sequestered under SRC remains a major challenge. [ABSTRACT FROM AUTHOR]

ABSTRACT Annual fiber sorghum (FS) and perennial giant reed (GR) cultivated in the Mediterranean area are interesting due to their high productivity under drought conditions and their potential use as lignocellulosic feedstock for biorefinery purposes. This study compares environmental constraints related to FS and GR produced on experimental farms (in the Campania region) using an attributional life cycle assessment (LCA) approach through appropriate modeling of the perennial cultivation. For both crops, primary data were available for agricultural management. Direct field emissions (DFEs) were computed, including the potential soil carbon storage (SCS). Giant reed showed the lowest burdens for all impact categories analyzed (most were in the range of 40%-80% of FS values). More apparent were the differences for climate change and freshwater eutrophication (respectively 80% and 81% lower for GR compared to FS). These results are due to the short-term SCS, experimentally detected in the perennial GR crop (about 0.25 ton C ha−1yr−1, with a global warming offsetting potential of about 0.03 ton CO2/tonGR dry biomass). The results are also due to the annual application of triple superphosphate at the sowing fertilization phase for FS, which occurs differently than it does for GR. Phosphorous fertilization was performed only when crops were being established and therefore properly spread along the overall crop lifetime. For both crops, after normalization, terrestrial acidification and particulate matter formation were relevant impact categories, as a consequence of the NH3 DFE by volatilization after urea were spread superficially. Therefore, the results suggest higher environmental benefits of the perennial crop than the annual crop. Integr Environ Assess Manag 2015;11:397-403. © 2015 SETAC [ABSTRACT FROM AUTHOR]

The cultivation of giant reed lignocellulosic feedstock on marginal land, appears of great interest in the Mediterranean basin, due to its high production potential under drought conditions. Starting from a three years field survey, in this paper a LCA was applied to the overall 15 years life cycle of a Mediterranean giant reed cultivation in Southern Italy, including Direct Field Emissions (DFE) and non-productive phases of cultivation. Agricultural practices performed yearly for field maintenance (FM-urea fertilization) and harvest operation (HO) shared the largest part of total burdens, nonetheless, the impact of crop establishment and final removal appeared significant. FM was strongly affected by DFE of soil biogenic N 2 O and fossil CO 2 (about 23% and 9% of total Climate change, respectively) and volatilized NH 3 (about 69%, 42% and 35% of total impact for Terrestrial acidification, Particulate matter formation and Marine eutrophication, respectively). For Marine eutrophication, also nitrate leaching in the plantation year, affected significantly the overall life cycle. Differently DFE linked to field application of K-P fertilizers for seedbed preparation (P and heavy metal emissions) and pest for final eradication (glyphosate emission), appeared more circumscribed. The study highlighted the need to carefully approach to soil carbon storage, and disclosed to be sensitive to uncertainty linked to DFE and crop yield pattern estimation. [ABSTRACT FROM AUTHOR]

Cropland expansion has been occurring over the last century, especially in South America, displacing non-crop areas mainly with soybean. Changes at a landscape level were followed by changes at a local scale, such as the adoption of insect-resistant transgenic crops. The homogenization of agroecosystem composition and agronomic practices have a great impact on arthropod predators and herbivore insects, which has not been quantified to a great extent in South America. We evaluate the effects of cover composition (1 km radii) as a landscape variable, and Bt adoption as a local variable on the quantity of the main predators and pests in soybean fields in Uruguay. Over a two-year period, we sampled 60 soybean fields with sweep net and beating sheet. We found that Bt and non-Bt soybean fields did not differ in the number of predators and stink bugs, while Bt fields were associated with less caterpillars' abundance. The proportion area of soybean negatively affected the quantity of some predators in this crop. In contrast, the landscape cover with natural grassland, commercial forest and maize positively affected some of these beneficial organisms. The number of stink bugs in soybean was highly affected by the surrounding cover composition. Arthropod responses depend on soybean's phenological period. We demonstrate the effects of the agriculturalization process on soybean predators and pests, suggesting that Bt adoption does not affect predators and each vegetation cover impacts them differentially. Different non-crop landscape cover and the abundance of predators in the field margin are positively associated with the abundance of predators in soybean fields. • Predator abundance in soybean do not decrease with the Bt adoption. • Field margins are an important source of arthropod predators to soybean fields. • Some non-crop and crops in the landscape increase soybean predator abundance. • Soybean area in the landscape could negatively affect predators. [ABSTRACT FROM AUTHOR]

Perennial crops require substantial initial investment in groundwork and planting, as well as a multiyear gestation period without commercial yield. Therefore, a crop's cycle (from planting to felling) should be long enough in order to cover the fixed cost and become profitable. The problem becomes involved when the cycle's duration is stochastic due to occurrence of uncertain event that terminates the cycle prematurely. Studying orchard management under stochastic drought events, we show that to each perennial crop that is profitable without drought hazard, there exists a critical drought hazard above which the crop turns loss making. We refer to this critical drought hazard as the crop's drought vulnerability index and show that it increases with the length of the gestation period, the ratio of fixed cost to average annual profit and the interest rate, and decreases with the natural (uninterrupted) cycle length. We then investigate the economic value of a stable water source, such as recycled water, that stabilizes the water supply and diminishes the drought hazard. An empirical application in northern Israel reveals that the stabilization value of recycled water due to its role in eliminating the drought hazard far exceeds its supply cost. [ABSTRACT FROM AUTHOR]

Highlights: [•] Four novel perennial crops were investigated for their biogas potential. [•] SMY (specific methane yield) were determined by batch fermentation experiments. [•] Szarvasi was found to provided high SMY at an early harvest date (end of June). [•] Energy dock and cup plant showed lower SMY on a medium level. [•] It was shown that harvest date influenced the SMY in the most cases significantly. [ABSTRACT FROM AUTHOR]

This paper presents analyses of the thermophysical and chemical properties of eleven perennial crop species harvested in one-year rotation cycles. The crops included four species grown for biomass in the form of straw, five species producing semi-wood biomass, and two species yielding wood biomass. The research comprised three consecutive crop harvests. In each harvesting season, biomass samples for analyses were taken on six dates at one-month intervals. Thermophysical and chemical properties of the biomass were significantly differentiated within the main experimental factors and their interactions. The biomass produced by Virginia mallow had the best quality parameters as solid fuel. In fact, it achieved the lowest water content and the highest lower heating value during all of the analyzed seasons and harvest dates. The biomass of the species yielding straw or semi-wood products attained better quality as solid fuel on later harvest dates. In turn, the quality of willow biomass remained practically unchanged between the harvest dates. [ABSTRACT FROM AUTHOR]

Highlights: [•] Perennial hay meadow develops labile organic P pools in place of occluded inorganic P. [•] Annual wheat develops occluded inorganic P pools in place of labile organic P. [•] Perennial hay meadow has an order of magnitude greater microbial biomass-P than annual wheat. [•] Long term fertilization enriches Pi and Po fractions to 46cm in wheat and 69cm in hay meadow. [•] Endogenous occluded P is depleted in 70–92cm strata in fertilized wheat and hay meadow. [Copyright &y& Elsevier]