Bottom-up effects are major ecological forces in crop-arthropod pest-natural enemy multitrophic interactions. Over the past two decades, bottom-up effects have been considered key levers for ...optimizing integrated pest management (IPM). Irrigation, fertilization, crop resistance, habitat manipulation, organic management practices, and landscape characteristics have all been shown to trigger marked bottom-up effects and thus impact pest management. In this review, we summarize current knowledge on the role of bottom-up effects in pest management and the associated mechanisms, and discuss several key study cases showing how bottom-up effects practically promote natural pest control. Bottom-up effects on IPM also contribute to sustainable intensification of agriculture in the context of agricultural transition and climate change. Finally, we highlight new research priorities in this important area. Together with top-down forces (biological control), future advances in understanding ecological mechanisms underlying key bottom-up forces could pave the way for developing novel pest management strategies and new optimized IPM programs.
Land-use and climate change are two of the key forces driving soil organisms’ activity and thus the ecosystem functions they provide. However, potential interactive effects of climate change and ...different land-use types on soil biological activity still remain unclear. Here, we studied soil biological activity in a large-scale field experiment initiated in 2014 in central Germany with two levels of input intensity (conventional versus organic treatment) and two climate scenarios (ambient climate versus “projected climate”, i.e., increased temperature by +0.55 °C and altered rainfall patterns across seasons). We measured soil microbial activity and invertebrate decomposer feeding activity across two years (2rd and 3rd year after establishment) in three-week intervals. Both soil biological activity measures were used as proxies for decomposition processes. Interactive effects of climate change and land-use types were not significant in the present study. Our results show that the projected climate reduced soil invertebrate decomposer activity by −16%, while soil microbial activity was not impaired. This suggests that even a slight increase in temperature together with a shift in precipitation patterns, can induce a significant reduction in soil functions like organic matter decomposition and nutrient cycling. Soil microbial (−9.6%) and invertebrate decomposer activity (−22%) were significantly lower in organic treatment compared to conventional treatment, which might be due to higher soil organic carbon and nutrient concentrations in conventional treatment in the short term. These findings highlight the need to better understand the main drivers of short- and long-term effects on belowground functioning to develop sustainable management strategies for healthy soils in a changing climate.
•Soil microbial activity is robust to climate change.•Summer drought has detrimental effects in soil invertebrate decomposer feeding activity.•Organic farming reduces soil microorganism and invertebrate decomposer activity two years after establishment.
Most stockless organic farms depend on the import of organic nitrogen. Biogas digestates offer an interesting solution to address this need for flexible nitrogen fertilizers. Their application could ...support the conversion of specialized arable farms, contributing to the politically targeted expansion of organic production. However, various regulations on the use of off-farm biogas digestates exist, which differ considerably in allowed N imports. Despite the growing interest in the application of biogas digestates in stockless organic farming in practice and research, its impacts on the economic potential of converting from conventional to organic farming have not been investigated.
This study assesses the economic potential of organic production for specialized arable farms without taking up animal production based on cooperating with a conventional biogas plant. The study considers the impacts of different regulations on importing off-farm biogas digestates.
The assessment employs the bio-economic farm model FarmDyn to evaluate multiple economic performance indicators for three stockless arable case study farms with varying cropping patterns under conventional and organic production. The German federal state of North Rhine-Westphalia serves as the case study area. A large-scale sensitivity analysis quantifies the impact of relevant parameters with a high uncertainty or possible large impact.
Our results suggest that organic farming has a high economic potential for specialized arable farms when biogas digestate is applied. Taking existing subsidies into account, organic farming economically outperforms conventional production for all assessed farms and regulatory scenarios. However, stronger restrictions on the application of biogas digestates shift crop rotations toward higher shares of crops with low nutrient requirements and legumes. This reduces, especially in case of fodder legumes, revenues and increases labor requirements, and lowers profitability and labor productivity. Distance to the biogas plant and subsidies for organic production impact strongly on profitability, whereas input prices show small effects. Results underline that the economic performance of stockless organic farming depends highly on import possibilities of nutrients. Furthermore, they suggest that subsidies for organic farming should better reflect its economic potential across farm types to reduce deadweight effects and boost conversion where it is costly.
The study is the first to assess the impact of different regulations governing the import of fermentation substrates on the economic potential of stockless organic farming for specialized arable farms. This is relevant as conversion of stockless arable farms is lagging behind but could considerably contribute to reach policy targets for organic production.
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•We assess the economic potential of organic production for specialized arable farms based on the import of biogas ferment.•Stockless organic farming has high economic potential, outperforming conventional farming for all assessed case study farms.•Differences in regulations on import of off-farm nitrogen in fermentation substrate impact strongly the economic potential.•The economic potential of organic farming depend strongly on the organic subsidy and the distance to the biogas plant.•Conversion of stockless arable farming is economically attractive and supports existing policy goals for organic production.
► Organic farming had similar or lower environmental impacts than integrated production. ► Organic farming used less resources, except land. ► Organic farming had higher biodiversity potential and ...lower ecotoxicity. ► Weak points of organic farming: lower yields and nutrient losses.
Organic farming (OF) is considered a promising solution for reducing environmental burdens related to intensive agricultural management practices. The question arises whether OF really reduces the environmental impacts once lower yields and all the changes in farming methods are taken into consideration. This question is addressed in a comprehensive study of Swiss arable cropping and forage production systems comparing OF to integrated production (IP) systems by means of the life cycle assessment (LCA) method.
The LCA study investigated the environmental impacts of two long-term farming system experiments: the DOC experiment comparing bio-dynamic, bio-organic and conventional/integrated farming and the “Burgrain” experiment encompassing integrated intensive, integrated extensive and organic production. All treatments received similar amounts of farmyard manure. The system boundary encompasses the plant production system; storage and application of farmyard manure is included in the system boundary, the animal husbandry is not included. The Swiss Agricultural Life Cycle Assessment method (SALCA) was used to analyse the environmental impacts.
In the overall assessment OF was revealed to be either superior or similar to IP in environmental terms. OF has its main strengths in better resource conservation, since the farming system relies mainly on farm-internal resources and limits the input of external auxiliary materials. This results in less fossil and mineral resources being consumed. Moreover the greatly restricted use of pesticides makes it possible to markedly reduce ecotoxicity potentials on the one hand, and to achieve a higher biodiversity potential on the other. This overall positive assessment is not valid for all organic products: some products such as potatoes had higher environmental burdens than their counterparts from IP.
The main drawbacks identified for Swiss OF systems are lower yields. As a consequence some production factors are used less efficiently, thus partly negating the advantages of OF. Furthermore, the different manure management strategy leads to relatively high nutrient losses in relation to yield. These two points were shown to be the main priorities for the environmental optimisation of OF systems. The differences between the bio-organic and the bio-dynamic farming systems consisted in a slightly higher input of organic matter, a few applications of mineral fertilisers and copper applications in the former.
The eco-efficiency analysis led to the conclusion that the optimisation of OF is mainly output-driven, i.e. that higher yields of good quality should be achieved with the available (limited) resources. On the contrary, optimisation of IP was found to be input-driven; the inputs should be used in a quantity and manner which minimise the environmental burdens per unit produced. The study showed that despite the efforts of recent years, there is still considerable room for the environmental optimisation of Swiss farming systems.
Intensive tillage and high inputs of chemicals are frequently used in conventional agriculture management, which critically depresses soil properties and causes soil erosion and nonpoint source ...pollution. Conservation practices, such as no-tillage and organic farming, have potential to enhance soil health. However, the long-term impact of no-tillage and organic practices on soil microbial diversity and community structure has not been fully understood, particularly in humid, warm climate regions such as the southeast USA. We hypothesized that organic inputs will lead to greater microbial diversity and a more stable microbial community, and that the combination of no-tillage and organic inputs will maximize soil microbial diversity. We conducted a long-term experiment in the southern Appalachian mountains of North Carolina, USA to test these hypotheses. The results showed that soil microbial diversity and community structure diverged under different management regimes after long term continuous treatments. Organic input dominated the effect of management practices on soil microbial properties, although no-tillage practice also exerted significant impacts. Both no-tillage and organic inputs significantly promoted soil microbial diversity and community stability. The combination of no-tillage and organic management increased soil microbial diversity over the conventional tillage and led to a microbial community structure more similar to the one in an adjacent grassland. These results indicate that effective management through reducing tillage and increasing organic C inputs can enhance soil microbial diversity and community stability.
Organic inputs and reduced tillage enhance microbial diversity and activities through increasing substrate availability and habitat heterogeneity. Display omitted
•Both no-tillage and organic farming improved soil microbial diversity and stabilize soil microbial community.•No-tillage combinate organic management enhanced soil microbial properties more than either individual practice.•Sustainable farming practices promote soil biological characteristics and may alleviate nonpoint source pollution.
There is an increased demand for food-grade grains grown sustainably. Hard red winter wheat has comparative advantages for organic farm rotations due to fall soil cover, weed competition, and grain ...yields. However, limitations of currently available cultivars such as poor disease resistance, winter hardiness, and baking quality, challenges its adoption and use. Our goal was to develop a participatory hard red winter wheat breeding program for the US Upper Midwest involving farmers, millers, and bakers. Specifically, our goals include (1) an evaluation of genotype-by-environment interaction (GEI) and genotypic stability for both agronomic and quality traits, and (2) the development of on-farm trials as well as baking and sensory evaluations of genotypes to include farmers, millers, and bakers' perspectives in the breeding process. Selection in early generations for diseases and protein content was followed by multi-environment evaluations for agronomic, disease, and quality traits in three locations during five years, on-farm evaluations, baking trials, and sensory evaluations. GEI was substantial for most traits, but no repeatable environmental conditions were significant contributors to GEI making selection for stability a critical trait. Breeding lines had similar performance in on-station and on-farm trials compared to commercial checks, but some breeding lines were more stable than the checks for agronomic, quality traits, and baking performance. These results suggest that stable lines can be developed using a participatory breeding approach under organic management. Crop improvement explicitly targeting sustainable agriculture practices for selection with farm to table participatory perspectives are critical to achieve long-term sustainable crop production.
Biochar (a carbon-rich product from pyrolysis of organic materials) addition to agricultural soils has been proposed as a novel technology for enhancing soil C storage and fertility; however, few ...studies have evaluated the effects of biochar on nutrients from an integrated perspective. Previous studies have demonstrated that biochar has the potential to improve bioavailable phosphorus (P) of sandy soils in organic farming systems; yet the underlying mechanisms remain poorly understood. We hypothesized that the unique characteristics of wood biochar could induce changes in soil microbial communities, which would subsequently drive biotic controls on soil P availability through microbial solubilization and/or mineralization and that this would be reflected in microbial P gene expression. To test this hypothesis, we determined the abundance and diversity of bacterial and fungal communities as related to microbial communities in sandy soils of organically-managed farmlands amended with locally produced wood biochar. A series of soil biochemical properties and genes encoding synthesis of phosphatase and those encoding the production of small molecular weight organic acids (involved in metal chelation and P solubilization) were directly quantified to help understand soil P mobilization following biochar addition. Three months after the application of wood biochar, the bioavailability of soil P was found to be elevated and a shift towards a bacterial dominated community was observed. Contrary to our hypothesis; however, the abundance of genes dictating soil phosphatase synthesis or organic acids production remained unaltered following biochar amendment. We suggest that the shift in P bioavailability could be controlled by abiotic mechanisms such as biochar-induced surface organic matter stabilization or adsorption/desorption of P associated with organo-mineral complexes. Although there was no specific molecular evidence of soil microorganism-mediated P mobilization, locally produced wood biochar had a positive effect on surface soil P bioavailability which could benefit agricultural soil health and ecosystem service delivery in organic farming systems.
•Biochar effect on P cycling was examined in a field study under organic farming.•The abundance of P cycling genes were quantified using digital droplet PCR.•Soils with biochar had higher enzyme extractable P and citrate extractable P.•The abundance of P genes was unaltered 3 months after biochar addition.•Potential biotic and abiotic mechanisms regarding soil P changes were discussed.
The concept of eco-culture has a sustainability paradigm that emphasizes the harmony of humans and ecosystems. The target is the strengthening of local characters through the study of local genius, ...as well as the application of science and technological innovation in managing the potential for improving the quality of the environment and humans. Increasing the economy through tourism is its added value. Kampung Baran has a unique ethnographic and geographical setting inhabited mostly by low-income people. The potential that can be developed is agriculture which is now slowly starting to be abandoned. This study examines the application of the eco-culture concept which consists of an image of space, an image of building, and an idealized concept of place for the development of Kampung Baran. Through a descriptive-phenomenological study, the researcher explores the physical-spatial-architectural and economic-social-cultural phenomena of Kampung Baran as the object of study. Furthermore, the study of the application of the concept of eco-culture in the village of Baran was carried out through a SWOT analysis. The results obtained indicate that the concept of eco-culture can be applied in Kampung Baran by emphasizing on strengthening the noble values of the culture of agrarian communities in the expression of tangible and intangible heritage that is adaptive to cultural dynamics and strengthening and developing local potential.
