Continued population growth and urbanization as well as changing consumption patterns have led to an explosion in the amount of waste produced, especially in cities. To feed the world, we also need ...to increase agricultural production while limiting our impact on the environment. Part of the solution could be to recycle the organic fraction of municipal solid waste (OFMSW) as a resource for agriculture near cities with techniques such as vermicomposting, which uses earthworms to recycle organic waste into nutrient-rich vermicompost. The objective of this review was to examine (i) whether vermicomposting is appropriate for recycling OFMSW, (ii) the quality of the vermicompost produced, and (iii) the impact of this product on crops and soil parameters. We found that vermicomposting can be adapted for OFMSW recovery because the process is suitable for all the types of OFMSW (food, paper, and green waste). The vermicompost produced is both high in organic carbon (18.83-36.01%) and a potential fertilizer (1.16-2.58% N, 0.42-1.12% P, and 0.61-2.05% K). A comparison with compost from the same types of OFMSW suggested that vermicompost is slightly more suitable for crop production with significantly lower C/N and pH and higher N and P. Vermicompost was actually found to have a better effect on plant growth than compost, suggesting that classical chemical analyses are not always sufficient to characterize the potential of organic amendments/fertilizers. Indeed, the application of vermicompost in the field leads to an increase in carbon storage, water retention, enzymatic and microbiological activity, and soil fauna abundance and diversity. Finally, we found that reports on the use of vermicompost from OFMSW are scarce and most studies focused on the process itself. Overall, our review synthesizes data and the interest in this technique and proposes perspectives for future studies.
The forecasted 9.1 billion population in 2050 will require an increase in food production for an additional two billion people. There is thus an active debate on new farming practices that could ...produce more food in a sustainable way. Here, we list agroecological cropping practices in temperate areas. We classify practices according to efficiency, substitution, and redesign. We analyse their advantages and drawbacks with emphasis on diversification. We evaluate the potential use of the practices for future agriculture. Our major findings are: (1) we distinguish 15 categories of agroecological practices (7 practices involve increasing efficiency or substitution, and 8 practices need a redesign often based on diversification). (2) The following agroecological practices are so far poorly integrated in actual agriculture: biofertilisers; natural pesticides; crop choice and rotations; intercropping and relay intercropping; agroforestry with timber, fruit, or nut trees; allelopathic plants; direct seeding into living cover crops or mulch; and integration of semi-natural landscape elements at field and farm or their management at landscape scale. These agroecological practices have only a moderate potential to be broadly implemented in the next decade. (3) By contrast, the following practices are already well integrated: organic fertilisation, split fertilisation, reduced tillage, drip irrigation, biological pest control, and cultivar choice.
•Conservation tillage in organic farming increase soil compaction.•Earthworm population doesnt increase after 10 years of conservation tillage.•Conservation tillage stratifies soil organic matter and ...nutrients in the topsoil.•Roots frequency is limited by soil compaction with conservation tillage.
It has become commonplace to consider ploughing as an agricultural practice that destroys soil fertility. Organic farmers have traditionally used the plough to till their soil and control weeds. However, there is a growing interest in adopting tillage practices without ploughing to preserve long-term soil fertility and in the hope, subsequently, of increasing crop yields. The aim of this paper is to assess if conservation tillage treatments in organic farming did in fact improve long-term soil fertility, wheat rooting and yield in a long term field experiment (2004–2015). We compared the effects of conservation tillage treatments (superficial tillage – ST- with chisel at 15cm depth and very superficial tillage – VST- at 5–7cm depth) and conventional tillage treatments (traditional mouldboard ploughing- MP at 30cm depth and shallow mouldboard ploughing – SMP- at 18cm depth without skim coulter) during 10 years on a sandy loam soil in France. To assess soil fertility, physical (soil penetration resistance, visual soil profile observation), chemical (organic carbon – Corg, total nitrogen – Ntot and available phosphorus – OlsenP) and biotic (earthworms biomass, density and diversity) soil properties were measured in 2004-5 and 2015. The effect of soil fertility on wheat roots and crop growth was also measured in 2015. VST, and to a lesser extent ST, increased Corg, Ntot and OlsenP in the upper soil layer (from 0 to 15cm) compared to ploughing treatments. On the contrary, soil compaction increased using conservation tillage treatments (VST and ST) during the 10 years of experiment, especially in the layers between 15 and 30cm depth in comparison with ploughing treatments. This effect is not offset by an increase in earthworm abundance and activities in conservation treatments. Earthworm biomass and endogeic abundance were even higher in SMP compared to ST. Soil compaction limits roots, with less roots in depth with VST (from 12 to 30cm and 48 to 70cm) and ST (from 24 to 30cm) compared to ploughing treatments. Conservation tillage treatments had positive effects on soil chemical components in the upper soil layer and contributed to the increase of wheat biomass until tillering stage. However, no wheat yield difference was found between treatments. Physical and biotic soil properties had not significantly improved after 10 years of conservation tillage. This could be due either to the insufficient duration of the experiment to foster a positive earthworm effect on soil porosity, or to the sandy soil, too sensitive to soil compaction in this organic cropping system (intensive mechanical weeding) and unfavourable for the development of the earthworm population.
Background and Aims: Organic farmers are showing increasing interest in using conservation tillage to improve the biological activities of soils. Here, we assessed whether conservation tillage in ...organic farming improves earthworm populations, root growth and soil physical quality in a sandy loam after 16 years of experiment. Methods: We compared the effect of a tillage gradient, with of two non-ploughed treatments (superficial tillage ST at 15 cm; very superficial tillage VST at 5–7 cm) and two ploughed treatments (moldboard ploughing MP at 30 cm; shallow moldboard ploughing SMP at 20 cm). Soil clod types, penetration resistance, abundance and activity of earthworms, root traits and biomass were assessed. Results: VST decreased soil compaction in topsoil (0 to 10 cm) compared to ploughed treatments (MP and SMP), but led to more compacted soil at 15 to 30 cm. Earthworm biomass (especially anecic) was higher under VST compared to MP and SMP and their galleries were better connected to the soil surface. However, there was no significant difference in the total volume of pores or diameter of galleries between 0 and 30 cm. Soil compaction in the non-ploughed treatments affected root traits, especially under VST, with lower specific root length, higher root diameter, and lower root tip elongation compared to MP and SMP. Conclusion: Biological activity did not compensate for the compaction of a sandy soil after 16 years without ploughing in organic farming. A more integrated approach (i.e. considering all 5 soil health principles) is needed to sustain soil health and functions, and meet current expectations about “ecological intensification”.
Organic fraction of municipal solid waste can be recovered using a variety of processes including composting, anaerobic digestion and vermicomposting. The impact of these products was evaluated using ...an innovative approach combining quantitative and qualitative analyses. Chemical analysis showed that the organic matter content of dry compost, digestate and vermicompost was 76 %, 67.2 % and 41.7 %, respectively. Index of Recalcitrant Organic Carbon (IROC) was higher for vermicompost (87.2 %) than for compost (77.9 %) or digestate (66.9 %). The Rock-Eval® approach was correlated to the IROC with its R-index (R2 = 0.97). Transmission electron microscopy was used to describe the microbial activity, the decomposition state and we observed more advanced maturity from vermicompost, compost to digestate. Finally, the digestate is predicted to have a fertilizing effect whereas the compost should have more an amending effect in the medium/long term. Due to a higher degree of stability, the vermicompost could have both a fertilizing and amending effect.
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•Amending potential of 3 different products from organic solid waste were compared.•Index of recalcitrance organic carbon was correlated with R-index of Rock-Eval®.•Microbial activity was assessed by characterization of product microstructures.•Product ranking was given according amending or carbon storage capacity.•Accurate complementary analyses for each product are proposed.
Because of its agronomic benefits, farm-scale composting is an efficient means of recycling agricultural waste. Composting process is an aerobic degradation of fresh organic matter in mature compost. ...Nevertheless, according to the literature, composting may induce some environmental problems. The environmental impacts of composting will be described, along with an assessment of farm-scale composting practices which play a major role in pollution. The main environmental components potentially affected by composting pollution are air and water. Various gases released by composting, such as NH sub(3), CH sub(4) and N sub(2)O, can impact air quality and are therefore studied because they all have environmental impacts and can be controlled by composting management. The effect on water quality can be evaluated by considering loss of NO sub(3) super(-), NH sub(4) super(+), organic compounds and PO sub(4) super(3-). Technical evaluation criteria for the impact of farm-scale composting on the air are determined from the physical and chemical characteristics of the raw materials, the use of additives, the turning method and frequency and the duration of the composting operations. Regarding water, the weather conditions at the beginning of the composting operation, the location of the heap, the protection against rain, the water addition during the process, the use of covers and the recovery of leaching and runoff water are also taken into account. The two main practices which control the air and water pollution from composting are: the choice of the raw material which influences gas emissions and the choice of composting location which have an high effect on losses by leaching and runoff.
Cover crop mulch-based no-tillage (MBNT) production is emerging as an innovative alternative production practice in organic farming (OF) to reduce intensive soil tillage. Although European organic ...farmers are motivated to implement MBNT to improve soil fertility and achieve further management benefits (e.g., labor and costs savings), low MBNT practice is reported in Europe. Thus, this paper aims to understand the challenges of both farmers and researchers limiting the further adoption of MBNT in organic farming in temperate climates. The primary no-tillage (NT) practices of organic European farmers and findings of organic MBNT studies conducted in Europe are reviewed, focusing on living or mulch cover crop-based NT (LBNT or MBNT) for arable crop production. Major conclusions drawn from this review indicate consistent weed control and an establishment of best practices for cover crop management as the two main overarching challenges limiting adoption. In view of substantial gaps of knowledge on these issues, additional research should focus on cover crop selection and management (species, date of sowing) to increase cover crop biomass, particularly in warmer climates. Lastly, further research is needed to optimize cover crop termination to prevent competition for water and nutrients with cash crops, particularly in wetter northern conditions which promote vigorous cover crop growth.
Organic farming relies heavily on tillage for weed management, however, intensive soil disturbance can have detrimental impacts on soil quality. Cover crop-based rotational tillage (CCBRT), a ...practice that reduces the need for tillage and cultivation through the creation of cover crop mulches, has emerged as an alternative weed management practice in organic cropping systems. In this study, CCBRT systems using cereal rye and triticale grain species are evaluated with organic soybean directly seeded into a rolled cover crop. Cover crop biomass, weed biomass, and soybean yields were evaluated to assess the effects of cereal rye and winter triticale cover crops on weed suppression and yields. From 2016 to 2018, trials were conducted at six locations in Wisconsin, USA, and Southern France. While cover crop biomass did not differ among the cereal grain species tested, the use of cereal rye as the cover crop resulted in higher soybean yields (2.7 t ha−1 vs. 2.2 t ha−1) and greater weed suppression, both at soybean emergence (231 vs. 577 kg ha−1 of weed biomass) and just prior to soybean harvest (1178 vs. 1545 kg ha−1). On four out of six sites, cover crop biomass was lower than the reported optimal (<8000 kg ha−1) needed to suppress weeds throughout soybean season. Environmental conditions, in tandem with agronomic decisions (e.g., seeding dates, cultivar, planters, etc.), influenced the ability of the cover crop to suppress weeds regardless of the species used. In a changing climate, future research should focus on establishing flexible decision support tools based on multi-tactic cover crop management to ensure more consistent results with respect to cover crop growth, weed suppression, and crop yields.
Reduced tillage reduces soil erosion and increases topsoil organic matter compared with conventional tillage. However, yields are often reported to be lower, presumably, due to increased weed ...pressure and a slower N mineralization under organic farming conditions. The effects of reduced tillage compared with ploughing on weed infestation and winter wheat performance at four different crop stages, i.e., tillering, stem elongation, flowering, and harvest, was monitored for a single season in an eleven-year-old organic long-term tillage trial. To disentangle the effects of weed presence on crop yield and potential crop performance, subplots were cleaned from weeds during the whole cropping season. Weed biomass was consistently higher under reduced tillage. Soil mineral nitrogen contents under reduced tillage management were higher, which could be explained by the earlier ley termination in autumn compared with the conventional tillage system. Nitrogen status of wheat assessed with SPAD measurements was consequently higher under reduced tillage throughout the season. At harvest, wheat biomass and grain yield were similar in both tillage systems in the presence of weeds, but 15–18% higher in the reduced tillage system when weeds were removed. The negative impact of weeds on yields were not found with conventional tillage with a low weed infestation. Results suggest that reduced tillage can provide equivalent and even higher yields to conventional tillage in organically managed winter wheat if weed management is improved and good nutrient supply is assured.
•Low earthworm taxonomic diversity was observed under Mediterranean conditions.•Organic fertilization significantly increased earthworm populations.•Endogeic earthworm species can benefit from soil ...inversion tillage.•Combining reduced tillage and green manure cropping did not show positive effects on earthworms.
Earthworms are one of the most important soil macrofaunal groups, and they play a major role in agricultural ecosystems. Agricultural practices, such as reduced tillage, the use of green manures and organic fertilization, can be beneficial for earthworm populations in agricultural systems. However, under a Mediterranean climate, not much is known regarding their response to agricultural management. The aim of this study was to analyse the effects of tillage type, organic fertilization, and green manures on the density and biomass of earthworms in organic arable dryland. The trial was conducted in a four-year crop rotation with a complete factorial design that combined tillage system (mouldboard ploughing vs. chisel), fertilization (composted farmyard manure vs. no fertilizer) and green manures (green manures vs. no green manures). Earthworms were assessed in each plot by the extraction of all individuals in three soil areas of 33cm×33cm that were excavated to a depth of 25cm. Only five earthworm species were found in this trial, and the earthworm community was dominated by such endogeic ecotypes as Aporrectodea rosea and Allolobophora georgii, and the anecic ecotype Aporrectodea trapezoides. Endogeic species can benefit from soil inversion because of the incorporation of organic matter, but the anecic ones can be negatively affected by it. The results show that plots with farmyard manure had higher density and biomass of earthworms. We observed that the type of tillage significantly affected earthworm populations: plots that had been ploughed with mouldboard ploughing (soil inversion) the year prior to sampling presented more juveniles. The biomass of earthworms was significantly lower in plots with green manures and chiselling. Our results indicated that the combination of chiselling and green manures were not optimal for earthworm populations, but organic fertilization played a considerably more important role and enhanced their abundances.
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