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.
Considering that pesticides have been used in Europe for over 70 years, a system for monitoring pesticide residues in EU soils and their effects on soil health is long overdue. In an attempt to ...address this problem, we tested 340 EU agricultural topsoil samples for multiple pesticide residues. These samples originated from 4 representative EU case study sites (CSS), which covered 3 countries and four of the main EU crops: vegetable and orange production in Spain (S–V and S–O, respectively), grape production in Portugal (P-G), and potato production in the Netherlands (N–P). Soil samples were collected between 2015 and 2018 after harvest or before the start of the growing season, depending on the CSS. Conventional and organic farming results were compared in S–V, S–O and N–P. Soils from conventional farms presented mostly mixtures of pesticide residues, with a maximum of 16 residues/sample. Soils from organic farms had significantly fewer residues, with a maximum of 5 residues/sample. The residues with the highest frequency of detection and the highest content in soil were herbicides: glyphosate and its main metabolite AMPA (P-G, N–P, S–O), and pendimethalin (S–V). Total residue content in soil reached values of 0.8 mg kg−1 for S–V, 2 mg kg−1 for S–O and N–P, and 12 mg kg−1 for P-G. Organic soils presented 70–90% lower residue concentrations than the corresponding conventional soils. There is a severe knowledge gap concerning the effects of the accumulated and complex mixtures of pesticide residues found in soil on soil biota and soil health. Safety benchmarks should be defined and introduced into (soil) legislation as soon as possible. Furthermore, the process of transitioning to organic farming should take into consideration the residue mixtures at the conversion time and their residence time in soil.
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•Pesticide residues werewe identified in EU soils of Organic/Conventional farms.•Total pesticide content in O-soils was 70–90% lower than in C-soils.•>70% of C-soils had mixtures of pesticide residues, maximal 16 residues/sample.•O-soils contained mainly mixtures of 2–5 residues, maximal 5 residues/sample.•Risk assessment of mixtures and related soil benchmarks are urgently required.
Conservation agriculture is considered as an agro-ecological approach to the sustainable and resource-saving crop production system. Previous studies on the adoption of agricultural innovation often ...consider socio-economic characteristics and overlook underlying psychological factors influencing farmers' behavioral intention. This study adopted three socio-psychological constructs, Attitude, Subjective Norm (SN), and Perceived Behavioral Control (PBC), which originated from the Theory of Planned Behavior (TPB), and proposed two new constructs, Knowledge (K) and Perceived Climatic Threats of Conventional Farming (PCTCV). Using the Extended Theory of Planned Behavior Model (ETPBM), this study analyzed factors affecting the intention of farmers to continue Conservation Agriculture (CA) for the following year (2020) in three districts located in the northern part of Bangladesh. This research found evidence from the hierarchical regression analysis that variables of ETPBM could explain 7% more variation (change in R2) in intention than variables of TPB, while the socio-economic characteristics of farmers can explain only 0.5% more than the variables of ETPBM. Structural Equation Modelling (SEM) was used to determine and examine the extended theory and indicated that farmers' knowledge (K) had the highest total impact, while attitude had the highest direct impact on intention. The results indicated that factors including Attitude, SN, PBC, Knowledge (K), and PCTCV are positively significant when attempting to understand farmers' intentions to adopt CA. This study presented evidence about the effectiveness of ETPBM when assessing the farmers' intentions towards conservation farming. Based on these findings, we concluded that the combination of extension services for upgrading the level of knowledge concerning the importance of CA could significantly affect farmers’ attitudes on intention towards the application of CA.
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•Socio-economic and psychological factors affecting intention were explored.•Knowledge and Perceived Climatic Threats of Conventional Farming were added to TPB.•All constructions of Extended TPB model significantly influenced intention.•Knowledge has the highest total impact and attitude has the highest direct impact.•Increased level of knowledge can improve farmers' intention.
•Microbial biomass was higher in organic farming topsoil than other land use.•Higher C cycle enzymes activities except xylanase in topsoil under organic farming.•Activities of N and S cycle enzymes ...were also higher in organic farming topsoil.•Xylanase and phosphatase activities were higher in conventional farming topsoil.•Land-use has smaller effect on microbial properties in subsoil.
Land-use change, especially from forest to intensive agriculture, is negatively impacting soil quality and sustainability. Soil biological activities are sensitive indicators of such land-use impacts. We tested two hypotheses: i) land use and management practices affect microbial properties (microbial biomass and enzyme activities) in topsoil (0–20cm), but have no effects in subsoil (20–100cm); and ii) microbial properties in topsoil are highest in forest, followed by organic farming and then conventional farming.
Total organic C and N contents as well as microbial biomass were significantly higher in the organic farming topsoil compared with conventional farming and forest. Except xylanase and acid phosphatase, enzyme activities (β-glucosidase, cellobiohydrolas, chitinase, sulfatase, leucine aminopeptidase and tyrosine aminopeptidase) were also higher in organic farming soil. Crop residues and rhizodeposits support higher microbial biomass, leading to enhanced enzyme activities in organic farming soil. Incorporation of rice stubble and limitation of available phosphorus explain the higher xylanase and acid phosphatase activities, respectively, in conventional farming soil. Litter removal leads to a deficiency of labile C and N, resulting in lower enzyme activities in forest soil. Total C and N contents were higher in subsoil under organic farming. Although there was no effect of land use on microbial biomass in subsoil, activities of most enzymes were higher under organic farming.
Overall, our results indicate that land-use change significantly alters microbial properties in topsoil, with modest effects in subsoil. Microbial properties should be considered in environmental risk assessments and models as indicators of ecosystem disturbance caused by land-use and management practices.
Regular weed surveys provide information on changes in weed communities. The composition of weed flora in spring cereal fields was investigated in southern and central Finland during 2020–2022. The ...survey was conducted in 16 regions, 226 farms and 549 fields. The occurrence of weeds was assessed in the second half of July from 90 organically cropped and 459 conventionally cropped fields. The weed flora was dominated by broad-leaved species, representing 81% of the total number of 138 identified species. The average species number per field was 21 in organic fields and 12 in conventional fields. The most frequent weed species in organic fields were Chenopodium album 99%, Erysimum cheiranthoides 84%, Viola arvensis 83% and Stellaria media 82%. In conventionally cropped fields, the most frequent species were Viola arvensis 83%, Stellaria media 65%, Galeopsis spp. 59% and Galium spurium 59%. The two most common grass species in both production systems were Poa annua and Elymus repens. The frequency and density of Poa annua had increased substantially in conventional cropping since the previous survey in 2007–2009. The average density of weeds was 384 plants m-2 in organic fields and 147 plants m-2 in sprayed conventional fields. The average air-dry biomass of weeds was 678 kg ha-1 and 151 kg ha-1, respectively. Elymus repens produced almost a quarter of the total weed biomass in both production systems. Changes in weed flora were minor in terms of frequency and density of the most common broad-leaved weed species. Increased infestation of Poa annua in conventional cropping calls for special attention. The dominance of Elymus repens decreased in both production systems since the previous survey.
•Hot air, microwave and infrared drying were employed on pepper powder production.•Higher amount of phenolic compounds was determined in organic pepper samples.•Phenolic compounds from LC–MS/MS ...increased significantly with the drying process.•Microwave and infrared methods were more effective to preserve aroma and phenolics, respectively.•Sensory analysis revealed that hot air-dried samples were least preferred.
Aroma, phenolic compounds and sensory properties of fresh and powdered organic and conventional sweet red peppers dried by three methods (hot air, intermittent microwave and infrared) were studied. The number of aroma compounds was higher in both fresh and powdered organic pepper samples; however, the total amount was higher in conventional samples. In both organic and conventional samples, alcohols were the dominant aroma group. (E)-β-ionone and β-ocimene, which are important compounds in peppers, were determined only in organic peppers. Among the drying methods, intermittent microwave drying was more effective in creating new aroma compounds. The liquid chromatography, coupled with tandem mass spectrometry (LC–MS/MS) revealed that luteolin derivative compounds comprised an average of 70% of the phenolics. Higher amount of phenolic were determined in organic samples. Infrared drying was more effective in retaining of phenolics than the other two methods. Sensory analysis revealed that hot air-dried samples were least preferred.
Organic and conventional farms often coexist, yet their proximity does not ensure compatibility. Larsen et al. reveal that being surrounded by organic fields reduces pesticide usage in organic fields ...but increases it in conventional fields. We discuss these findings, emphasizing the need to cluster organic croplands for reduced pesticide use.
Organic and conventional farms often coexist, yet their proximity does not ensure compatibility. Larsen et al. reveal that being surrounded by organic fields reduces pesticide usage in organic fields but increases it in conventional fields. We discuss these findings, emphasizing the need to cluster organic croplands for reduced pesticide use.
We hypothesize that biological diversification across ecological, spatial, and temporal scales maintains and regenerates the ecosystem services that provide critical inputs—such as maintenance of ...soil quality, nitrogen fixation, pollination, and pest control—to agriculture. Agrobiodiversity is sustained by diversified farming practices and it also supplies multiple ecosystem services to agriculture, thus reducing environmental externalities and the need for off-farm inputs. We reviewed the literature that compares biologically diversified farming systems with conventional farming systems, and we examined 12 ecosystem services: biodiversity; soil quality; nutrient management; water-holding capacity; control of weeds, diseases, and pests; pollination services; carbon sequestration; energy efficiency and reduction of warming potential; resistance and resilience to climate change; and crop productivity. We found that compared with conventional farming systems, diversified farming systems support substantially greater biodiversity, soil quality, carbon sequestration, and water-holding capacity in surface soils, energy-use efficiency, and resistance and resilience to climate change. Relative to conventional monocultures, diversified farming systems also enhance control of weeds, diseases, and arthropod pests and they increase pollination services; however, available evidence suggests that these practices may often be insufficient to control pests and diseases or provide sufficient pollination. Significantly less public funding has been applied to agroecological research and the improvement of diversified farming systems than to conventional systems. Despite this lack of support, diversified farming systems have only somewhat reduced mean crop productivity relative to conventional farming systems, but they produce far fewer environmental and social harms. We recommend that more research and crop breeding be conducted to improve diversified farming systems and reduce yield gaps when they occur. Because single diversified farming system practices, such as crop rotation, influence multiple ecosystem services, such research should be holistic and integrated across many components of the farming system. Detailed agroecological research especially is needed to develop crop- and region-specific approaches to control of weeds, diseases, and pests.
The benefits of organic farming to biodiversity in agricultural landscapes continue to be hotly debated, emphasizing the importance of precisely quantifying the effect of organic vs. conventional ...farming. We conducted an updated hierarchical meta‐analysis of studies that compared biodiversity under organic and conventional farming methods, measured as species richness. We calculated effect sizes for 184 observations garnered from 94 studies, and for each study, we obtained three standardized measures reflecting land‐use intensity. We investigated the stability of effect sizes through time, publication bias due to the ‘file drawer’ problem, and consider whether the current literature is representative of global organic farming patterns. On average, organic farming increased species richness by about 30%. This result has been robust over the last 30 years of published studies and shows no sign of diminishing. Organic farming had a greater effect on biodiversity as the percentage of the landscape consisting of arable fields increased, that is, it is higher in intensively farmed regions. The average effect size and the response to agricultural intensification depend on taxonomic group, functional group and crop type. There is some evidence for publication bias in the literature; however, our results are robust to its impact. Current studies are heavily biased towards northern and western Europe and North America, while other regions with large areas of organic farming remain poorly investigated. Synthesis and applications. Our analysis affirms that organic farming has large positive effects on biodiversity compared with conventional farming, but that the effect size varies with the organism group and crop studied, and is greater in landscapes with higher land‐use intensity. Decisions about where to site organic farms to maximize biodiversity will, however, depend on the costs as well as the potential benefits. Current studies have been heavily biased towards agricultural systems in the developed world. We recommend that future studies pay greater attention to other regions, in particular, areas with tropical, subtropical and Mediterranean climates, in which very few studies have been conducted.
Soil is one of the biggest reservoirs of microbial diversity, yet the processes that define the community dynamics are not fully understood. Apart from soil management being vital for agricultural ...purposes, it is also considered a favorable environment for the evolution and development of antimicrobial resistance, which is due to its high complexity and ongoing competition between the microorganisms. Different approaches to agricultural production might have specific outcomes for soil microbial community composition and antibiotic resistance phenotype. Therefore in this study we aimed to compare the soil microbiota and its resistome in conventional and organic farming systems that are continually influenced by the different treatment (inorganic fertilizers and pesticides vs. organic manure and no chemical pest management). The comparison of the soil microbial communities revealed no major differences among the main phyla of bacteria between the two farming styles with similar soil structure and pH. Only small differences between the lower taxa could be observed indicating that the soil community is stable, with minor shifts in composition being able to handle the different styles of treatment and fertilization. It is still unclear what level of intensity can change microbial composition but current conventional farming in Central Europe demonstrates acceptable level of intensity for soil bacterial communities. When the resistome of the soils was assessed by screening the total soil DNA for clinically relevant and soil-derived antibiotic resistance genes, a low variety of resistance determinants was detected (resistance to β-lactams, aminoglycosides, tetracycline, erythromycin, and rifampicin) with no clear preference for the soil farming type. The same soil samples were also used to isolate antibiotic resistant cultivable bacteria, which were predominated by highly resistant isolates of
and
genera. The resistance of these isolates was largely dependent on the efflux mechanisms, the soil
spp. relying mostly on RND, while
spp. and
spp. on RND and ABC transporters.
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