查看更多>>摘要：? 2022 Elsevier B.V.Ecological infrastructures (EI), defined as natural or semi-natural structural elements, are important to support biodiversity and could play a crucial role in counteracting the well-known impacts of intensive agriculture. Yet, the importance of EI remains largely unexplored in Mediterranean agricultural landscapes and for species providing essential ecosystem services such as bats. Here, we evaluated the role of different EI types – in terms of location (riparian vs terrestrial) and vegetation physiognomy (woody vs non-woody) – in shaping bat guild activity in crop fields located in the floodplains of the Iberian Peninsula. We recorded 60,732 bat sequences in 96 crop fields and characterised 106 EI patches via an adaptation of the Biodiversity Potential Index (BPI). We found that the activity of mid-range echolocators (MRE) and long-range echolocators (LRE) was twofold higher when the nearest EI patch was riparian (i.e., contiguous to a watercourse) than when it was terrestrial. When assessing changes in bat activity in crop fields in relation to a gradient distance from EI types, our results revealed both distinct and similar effects of the location and vegetation physiognomy of the EI on bat guilds. For instance, while only the LRE guild positively responded to the proximity of woody EI, both MRE and LRE showed a marked increase of activity when increasing distances to non-woody EI, thus suggesting low bat activity levels near these features. Our habitat quality assessment also revealed that woody EI and riparian EI had higher biodiversity potential and related habitat quality, thus contributing to our understanding of bat responses to EI type in crop fields. As riparian areas are rarely targeted in biodiversity-friendly measures in farmland, we strongly recommend including riparian EI (especially the woody type) in conservation planning as they are crucial for both biodiversity conservation and ecosystem functioning.
查看更多>>摘要：? 2022 The AuthorsConventional high-input farming systems in Europe are often regarded as unsustainable with severe environmental impacts on biodiversity, soils, water and climate. Low-input farming approaches, such as organic farming, have been proposed to reduce environmental impacts while further improving soil properties such as soil organic matter content and aggregate stability. Whether these changes also influence ecohydrological properties and improve the water relations of organically grown crops remains unclear. In this study we assessed the long-term effects of conventional and organic farming systems on the water relations of soils and crops in the “DOK” (bio-Dynamic, bio-Organic & ‘Konventionell’ = conventional) trial. In particular, we tested if organic and conventional farming lead to marked differences in soil moisture, soil water evaporation, as well as root water uptake depth and stomatal conductance of winter wheat and soybean during the growing seasons 2017 and 2018. Stable isotope analyses and ecophysiological measurements revealed that organic compared to conventional farming did not affect soil water evaporation or root water uptake depths. Instead, we found higher soil moisture in the rooting zone and reduced stomatal conductance (gs) in organically grown wheat. Treatment effects on soil moisture and gs of soybean were smaller but showed similar tendencies as observed in wheat. Also, leaf area, and grain and straw yield of wheat decreased under organic farming while yields of soybean were not affected by the treatments. Based on our data we suggest that reduced plant water use observed under organically managed farming lead to the observed higher soil moisture in organically compared to conventionally managed farming systems in the DOK trial. These results suggest advantages of organic farming regarding agronomic water use as well as for the resistance of farming systems to current or future drought scenarios.
查看更多>>摘要：? 2022 Elsevier B.V.Farming systems maintain ecosystem services related to arthropod biodiversity, which need to be understood for its effective conservation. Some of these arthropods may also be enemies of crop pests. It has been shown that farming systems surrounded by other types of natural or semi-natural land covers/uses are less affected by pests. The abundance and richness of hymenopteran parasitoid (HP) families in olive groves were analysed along a gradient of complexity of the landscape surrounding these agroecosystems. The working hypothesis was that landscape structure is related to the abundance and richness of HP families. Through principal component analysis of samples analysed in 15 olive groves during the springs and autumns of 2015 and 2016, we found that a higher richness of HP families is associated to simple landscapes with olive grove predominance and a lower richness in landscapes with higher diversity of land uses. The most abundant families in olive-dominated landscapes were Pteromalidae, Encyrtidae and Eulophidae, and the least abundant were Elasmidae, Eupelmidae, Chrysididae, Platygastridae and Eurytomidae. In the most diverse olive grove landscapes only three families appeared: Mymaridae, the most abundant, and Diapriidae and Signiphoridae with lower abundance. Scelionidae was the most abundant family in all olive landscapes, both simple and complex. The greater richness and abundance of HP in olive-dominated landscapes does not guarantee biological control, but it does provide conservation of arthropod biodiversity as a cross-cutting ecosystem service.
查看更多>>摘要：? 2022 Elsevier B.V.Achieving carbon neutrality is a global goal, and increasing crop yield while reducing agriculture-related greenhouse gas (GHG, including CO2, CH4, and N2O) emissions is an urgent challenge. In the dryland of northwest China, the high input of nitrogen (N) fertilizer drives high GHG emissions. Replacement of part of the N fertilizer with manure (NM) and adding supplemental irrigation water (NMW) to NM can significantly increase crop yields. However, it is still unknown whether the increased yield would induce more GHG emissions. In this study, the change in GHG emissions were investigated under conventional farmer N application (FN), NM and NMW in winter wheat cropping systems. The two-year study showed that the global warming potential, greenhouse gas intensity and carbon footprint of NM and NMW were 3–25%, 21–42% and 9–18% lower, respectively, than those of FN, owing to the lower N fertilizer and the associated N2O emissions under NM and NMW. In addition, compared with FN, CO2 emissions during the growing season were higher under NM and NMW; however, due to the 23–40% higher biomass productivity, NM and NMW neutralized and fixed more CO2 (21–39% higher net ecosystem productivity) than FN. Therefore, NM and NMW could be favorable agronomic practices in the Loess Plateau when considering the dual goal of maintaining acceptable yields while reducing GHG emissions.
查看更多>>摘要：? 2022 Elsevier B.V.Winter cover crop cultivation during the fallow season has been strongly recommended in single crop cropping systems to improve soil quality, but its impact on the soil greenhouse gas (GHG) emissions of the soil has not been extensively studied. This study aimed to investigate the effects of replacing traditional winter fallow with a cover crop combined with a reduced amount of nitrogen (N) fertilizer on ammonia (NH3) volatilization, GHG emissions, and cotton production yield. A field experiment was performed with two cropping systems (a single cotton system and February orchid (Orychophragmus violaceus L.) incorporated into a single cotton cropping system) and four N levels (0, 112.5, 168.75 and 225.0 kg N ha?1). The results showed that the incorporation of February orchid increased cotton yield, nitrous oxide (N2O) emission, NH3 volatilization, global warming potential (GWP), and net ecosystem carbon budget (NECB) under the same N application rate. Moreover, the NH3, N2O, GWP, yield GWP, and NECB increased with an increasing N application rate. Furthermore, the correlation and redundancy analysis (RDA) results indicated that N2O emissions and NH3 volatilization were positively affected by soil NO3- -N, total nitrogen (TN) and lint cotton yield. Overall, compared with the single cropping of cotton with conventional fertilization, the incorporation of February orchid with a 25% reduction in the N application rate decreased NH3 volatilization by 1.05 kg NH3-N ha?1 and N2O losses by 0.34 kg N2O-N ha?1 and resulted in a favorable cotton yield. Our results demonstrate that replacing traditional winter fallow with a cover crop combined with a N fertilizer reduction may help to mitigate soil GHG emissions and NH3 volatilization while ensuring yield in cotton production. In future studies, the evaluation of cropping system GHG emissions should be considered from a life-cycle perspective, and attention should be given to the legacy impacts of N.
查看更多>>摘要：? 2022 The AuthorsHerbivorous waterfowl populations have increasingly adapted to forage on agricultural land and triggered a parallel rise in damage to agricultural crops. Winter wheat (Triticum aestivum) is the most commonly reported crop damaged in northern Europe, and farmers increasingly demand management actions to mitigate economic impacts. Here, we apply two parallel approaches (exclosure experiments in undisturbed fields and yield assessments in fields subject to scaring) to quantify the impact of waterfowl grazing on winter wheat yield, crop height and nutrient content. We demonstrate that waterfowl grazing led to a substantial reduction in crop height during winter and early spring, but also that compensatory growth led to no significant effect on crop height at the time of harvest. In terms of grain yield, the effect of waterfowl grazing varied from non-significant to a 6% loss, and on fields subject to scaring, the negative effect of grazing was only significant when grazing continued into spring (the case for 7.6% of the area sampled). In addition, the exclosure experiments indicated that plots grazed both winter and spring had a protein content 9% lower than ungrazed plots. While these figures express an economic loss to the affected farmers, our findings also indicate that substantial economic impacts from grazing waterfowl on winter wheat was rare in our study area. This may also be the case elsewhere in the temperate region, when most waterfowl abandon crop foraging in due time to allow for compensatory growth in late spring, and as long as the early developmental stages survive the early impacts from grazing. A substantial scaring effort had only a limited effect on grain yield loss when fields were grazed during spring, but seemed to prevent damage on fields that were grazed only during winter. Future decision-making in relation to the waterfowl-agriculture conflict may benefit from studies looking in-depth at the costs and benefits associated with scaring efforts.
查看更多>>摘要：? 2022 Elsevier B.V.Climate and land-use change are some of the most profound threats to the biodiversity and functioning of the Earth's ecosystems. However, potential synergistic effects of these drivers through biodiversity change on ecosystem functioning remain unclear. Here we examined how aridity and land-use (overgrazing and haying) affect above-ground biomass and soil organic carbon (SOC) through changes in plant species richness across 701 grassland sites in China. We found that aridity and grazing reduced SOC through decreasing plant species richness, but did not significantly affect above-ground biomass. Notably, we observed strong negative synergistic effects of aridity and grazing, suggesting that soil carbon content was particularly threatened by grazing in arid environments. By contrast, haying reduced above-ground biomass and had no significant effect on SOC, although it increased plant species richness. Plant species richness had greater positive effects on SOC than on above-ground biomass, and its effects became stronger in more arid regions. Together, the results demonstrate that aridity and overgrazing threaten soil carbon content via their detrimental effects on plant diversity, and that detrimental overgrazing effects are particularly strong under arid conditions. However, the study also indicates that certain management types like haying or less intensive grazing can maintain or enhance plant diversity and soil carbon content, and that the beneficial effects of plant diversity are particularly important in arid environments.
查看更多>>摘要：? 2022 Elsevier B.V.Crop residue incorporation as general cropland management practice notably improves soil organic carbon (SOC) stock. However, the effects of crop residue input rate incorporation on SOC stability remain uncertain. Here, we conducted a 12-year field experiment to evaluate the long-term effects of crop residue incorporation on SOC stocks, stabilities, and their abiotic and biotic controls in subtropical calcareous soil under a maize-wheat rotation. Four experimental treatments, including no crop residue incorporation (control), 30% of harvested crop residue incorporation (CR30), 50% of harvested crop residue incorporation (CR50), and 100% of harvested crop residue incorporation (CR100), were implemented. Our results showed that the CR100 treatment significantly increased SOC stock by 25.6%, as compared with the control. Soil dissolved organic carbon (DOC) and particulate organic carbon (POC) contents for CR100 treatment were also significantly greater than those for the control, while no significant difference in soil microbial biomass carbon (MBC) content across different experimental treatments were found. POC content for CR50 was significantly lower than the other treatments. It is noteworthy that the relative abundance of Thaumarchaeota related to microbial SOC decompositions for CR100 was significantly lower than other experimental treatments. The temperature sensitivity (Q10) of SOC mineralization for CR50 treatment was significantly higher, as compared with other treatments. Nevertheless, the partial least squares path modeling analysis (PLS-PM) illustrated that soil aggregation and DOC content were the main regulators of Q10 for SOC mineralization thereby regulating the stability of SOC. Our results suggest that the practice of 100% of harvested crop residue incorporation is effective to increase the magnitude and the stability of SOC stocks in subtropical calcareous agricultural soils, in particular on a long-term basis.
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