Earthworm Weight Research Articles

Biochemical responses, growth and reproduction of earthworm in low density polyethylene (LDPE)

AbstractThere is an unprecedented production of plastic that is accelerating its disposal while affecting the fitness of the terrestrial as well as the aquatic environment. The term microplastics refers to plastic fragments that are less than 5 mm in size and are widely distributed in the environment. Therefore, the present study intends to explore the biological response of earthworms (Eisenia fetida) toward different concentrations of low‐density polyethylene. E. fetida treated with low‐density polyethylene concentration (Control), 250 mg kg−1, 1000 mg kg−1, 6000 mg kg−1, 12,000 mg kg−1, and 25,000 mg kg−1. The above ratios were thoroughly mixed with 1kg of artificial soil and tested for growth, reproduction (cocoons and hatchling count), and enzymatic activities namely superoxide dismutase, guaiacol peroxidase, glutathione‐S‐transferase, and glutathione reductase and molecular docking studies. No mortality was observed during the exposure period at any concentrations. On the 28th day, when compared to the control the highest decrease in body weight of earthworms was observed in 25,000 mg (28.4%) followed by 12,000 mg (12.2%) and 6000 mg (3.4%). The cocoon and hatchlings significantly declined as the dose of microplastics increases. Enzymatic activity such as SOD and POD showed declined trend as the dose increased, while GST and GR increased with an increase in microplastic concentrations on 28th day. Furthermore, molecular docking showed that LDPE can modulate the activity of all four enzymes significantly.

Responses of earthworms exposed to low-density polyethylene microplastic fragments

The interest in the effect of microplastics (MPs) on the terrestrial environment has been increasing recently. Different species of earthworms have been used to study the effects of MPs on different aspects of earthworm health. However, there is still a need for more studies because different studies report different effects on earthworms depending on the properties (e.g., types, shapes, sizes) of MPs in the environment and exposure conditions (e.g., exposure period). This study used Eisenia fetida as a test earthworm species to investigate the effect of different concentrations of low-density polyethylene (LDPE) MPs (≤125 μm) in soil on the growth and reproduction of earthworms. The exposure of the earthworms to the different concentrations of LDPE MPs (0–3% w/w) for 14 d and 28 d neither caused death of the earthworms nor showed significant effects on the earthworm weights in this study. The number of cocoons produced by the exposed earthworms were also similar to that of the controls (i.e., no exposure to MPs). Some previous studies reported similar results to what have been observed in this study, while some studies reported different results. On the other hand, the number of ingested MPs by the earthworms increased with increasing MPs concentrations in soil, suggesting a potential for damage to digestive tract. Also, the earthworm skin surface was damaged after exposure to MPs. The ingested MPs and the skin surface damage suggest that there is a potential for adverse effects on the earthworm growth after a longer-term exposure. Overall, the results of this study show that the effects of MPs on earthworms need to be studied using various endpoints including growth, reproduction, ingestion, and skin damage and such effects can be different depending on the exposure conditions such as MPs concentration and exposure period.

Effects of microplastics and chlorpyrifos on earthworms (Lumbricus terrestris) and their biogenic transport in sandy soil

Although microplastics (MPs) are ubiquitous in agricultural soil, little is known about the effects of MPs combined with pesticides on soil organisms and their biogenic transport through the soil profile. In this study, we conducted mesocosm experiments to observe the effects of microplastics (polyethylene (LDPE-MPs) and biodegradable microplastics (Bio-MPs)) and chlorpyrifos (CPF) on earthworm (Lumbricus terrestris) mortality, growth and reproduction, as well as the biogenic transport of these contaminants through earthworm burrows. The results showed that earthworm reproduction was not affected by any treatment, but earthworm weight was reduced by 17.6% and the mortality increased by 62.5% in treatments with 28% Bio-MPs. Treatments with 28% LDPE-MPs and 7% Bio-MPs combined with CPF showed greater toxicity while the treatment with 28% Bio-MPs combined with CPF showed less toxicity on earthworm growth as compared to treatments with only MPs. The treatments with 1250 g ha−1 CPF and 28% Bio-MPs significantly decreased the bioaccumulation of CPF in earthworm bodies (1.1 ± 0.2%, w w−1), compared to the treatment with CPF alone (1.7 ± 0.4%). With CPF addition, more LDPE-MPs (8%) were transported into earthworm burrows and the distribution rate of LDPE-MPs in deeper soil was increased. No effect was observed on the transport of Bio-MPs. More CPF was transported into soil in the treatments with LDPE-MPs and Bio-MPs, 5% and 10% of added CPF, respectively. In addition, a lower level of the CPF metabolite 3,5,6-trichloropyridinol was detected in soil samples from the treatments with MPs additions than without MP additions, indicating that the presence of MPs inhibited CPF degradation. In conclusion, Bio-MPs caused significant toxicity effects on earthworms and the different types of MPs combined with CPF affected earthworms differently, and their transport along the soil profile. Thus, further research is urgently needed to understand the environmental risks of MPs and MP-associated compounds in the soil ecosystem.

Plasma-Treated Nitrogen-Enriched Manure Does Not Impose Adverse Effects on Soil Fauna Feeding Activity or Springtails and Earthworms Abundance

Plasma treatment of animal manure is a new technology, enriching the manure with plant-available nitrogen. Therefore, the product is termed nitrogen-enriched organic fertilizer (NEO). The producer (N2 Applied) claims that NEO can be a sustainable alternative to conventional fertilizers used in agriculture. However, the effect of this product on soil-dwelling organisms is unknown. This study investigates and compares the effects of NEO on changes in soil fauna feeding activity, the abundance of springtails, and the abundance and weight of earthworms to mineral fertilizer, organic fertilizer (cattle slurry), and no fertilizer in pot and field experiments with sandy clay loam soil. Early effect evaluation (week 7) indicated influences on soil fauna feeding activity; among treatments, higher amounts of fertilizers went along with lower feeding activity, regardless of fertilizer type. However, the initial fertilizer application stimulation was transient and stabilized with time after fertilization towards mid-term (week 14) and late effect evaluations (week 21). Accordingly, differences between feeding activities were less than five percent at late effect evaluation. Similarly, none of the fertilizers used imposed adverse effects on the abundance of springtails and the abundance and weight of earthworms; these parameters were almost identical among all fertilizing treatments. After two years of application in field trials and in a pot experiment, NEO and the other used fertilizers seem not to harm the selected soil-dwelling organisms.

Effect of The Addition of Hyacinths as Feed to Increase The Production of Earthworms (Lumbricus rubellus)

Water hyacinth (Eichhornia crassipes) is one of Indonesia's wild plants which is considered a weed because of its rapid growth that can cause environmental problems. Generally, water hyacinth control is carried out physically/conventionally by throwing it away or burning it, causing new environmental problems. Water hyacinth has a high organic matter content, therefore water hyacinth can be used as an alternative feed to increase the production of earthworms. This study aims to determine the effect of adding water hyacinth as feed to increasing the production of earthworms (Lumbricus rubellus).This study aims to determine the effect of adding water hyacinth as feed to increasing the production of earthworms (Lumbricus rubellus). The research was conducted in the Dasan Dao hamlet, Ranggagata Village, Southwest Praya District, Central Lombok Regency, in the researcher's private house for 60 days. This type of research is an experimental research. The research design used was a completely randomized design with 4 treatments and 4 replications. Treatments were P0 (0 grams of water hyacinth), P1 (50 grams of water hyacinth), P2 (100 grams of water hyacinth), P3 (150 grams of water hyacinth). Parameters observed were the number and weight of earthworms. The results showed that the treatment had a significant effect on the weight and number of earthworms (P<0.05). The results of the treatment on the number of earthworms P0;P1;P2;P3 were 84;93.75;117.25;127.5 and the weight of earthworms was 85;102.5;118.75;124.75. The highest number and weight of earthworms were found in the P3 treatment (150 g of water hyacinth). The conclusion of this research is the addition of water hyacinth as feed can increase the number and weight of earthworms.

Study of the Effect of Mercury Salt on the Presence of Annelida (Lumbricus terrestris) in Soil and the Histological Changes on the Skin Tissue

The earthworm is the most beneficial organism for assessing metallic contamination due to the fact that critical high-quality correlations have been determined between earthworm steel concentrations and soil cadmium, copper, lead, zinc, and mercury concentrations. The mercury compounds are very poisonous for most organisms. Here, we investigated the ability of earthworms (Lumbricus terrestris) to HgCl2 (below laboratory conditions). A study of the effect of five different salt concentrations of mercury chloride (HgCl2) 1 ppm, 5 ppm, 10 ppm, 50 ppm, and 100 ppm was studied on worm survival and calculation of the concentration required to destroy half the number of worms (LC50). The results showed that there is an inverse relationship between these salt concentrations and the time required to perish 100% of worms. It was found that the concentration of 100 ppm is the lethal concentration of half the number (LC50) of the earthworm (Lumbricus terrestris). The effects of the salt concentrations used confirmed their effect on the experimental worm weights as well, so the concentration of 50 ppm was the most influential on earthworm weights of the type of Lumbricus terrestris, as it caused a reduction 12% of worm weights with a significant difference, while the concentrations 1 ppm and 100 ppm were the least effective, as they caused the worms to decrease by only (5%), while the remaining two concentrations 5 ppm and 10 ppm caused their effect to decrease by 7% only. Thus, it can be concluded that lower worm weights have nothing to do with the lethal concentrations of the heavy metal salt (HgCl2). The histological study also showed that low concentrations of mercury chloride salt have less effect on earthworms’ skin tissue compared to higher concentrations.

POTENSI BUDIDAYA CACING TANAH SEBAGAI BIOKOMPOS DAN BIOFEED

Making biocompost can use earthworms. Compost produced by earthworm activity works with the help of other soil microbiota which contains many soil enzymes and hormones that are beneficial for plant growth. Earthworms are also rich in protein which has the potential to be used as animal feed (biofeed), considering that the demand for animal feed tends to be higher in line with the increase in livestock cultivation activities in Indonesia. Earthworms are expected to be the main raw material for quality animal feed (biofeed) as well as a solution to the problem of waste so far by making it into biocompost. This research was carried out in the Green house and Laboratory of Biology PMIPA Muhammadiyah Metro University, Metro City, Lampung Province from January 2021 to March 2022. This type of research is descriptive qualitative using the vermicomposting method. The species used are Eudrilus sp. There are controls and 3 treatments. Each treatment was repeated 3 times. The variations in the comparison of compost media, feces and feed in the form of organic waste (remains of vegetables and fruit) in sequence are: P0 (control) = 0 kg of feces: 1 kg of media, P1 = 75 grams of feces: 25 grams of media, P2 = 50 g of fecal sludge: 50 g of media, P3 = 25 g of faecal sludge: 75 g of media. Primary data in the form of worm cultivation activities with parameters/variables: how many g/kg of vermicompost are produced, how much weight and number of cocoons (eggs) of earthworms. While secondary data in the form of literature searches research journals, books and internet searching. All data, both primary and secondary data, were analyzed descriptively and processed by tabulation. Based on the results of the study, it was concluded that in the 3rd treatment (P3) with a combination of 25 g of fecal sludge and 75 g of media, the highest value was obtained for the parameters of earthworm weight (8.7 g) and the number of cocoons (11.6 pieces). The weight and number of earthworm cocoons is strongly influenced by the adequacy of nutrients from the media and environmental conditions. Other research needs to be done to see the number of vermicomposts produced, as well as the application of vermicompost to plant growth.

Ecotoxicity risk study of petroleum hydrocarbon contaminated soil

Petroleum is an important industrial raw material that enters the soil in large quantities due to its production and extraction, causing toxic effects on soil organisms. To evaluate the toxicity of petroleum-contaminated soil, the study was conducted to qualitatively and quantitatively investigate the ecotoxicity of petroleum-contaminated loessal soil with different levels of petroleum. Using earthworms and wheat as indicator organisms by microcosm toxicity test. The earthworm test showed that the body weight of earthworms decreased by more than 20% with the addition of 800-3,000 mg/kg TPHs and by more than 50% with the addition of 13000 mg/kg or more TPHs. The EC50 values at 7 and 14 d were 21,130 and 25,314.5 mg/kg, respectively. The number of sprouts, shoot length and root length of wheat were inhibited in the soil with petroleum, and the more severe the petroleum contamination, the stronger the inhibition. The seedling elongation index was better than the root elongation index. The experimental results showed that earthworms had the lowest EC50 values for body weight inhibition at 7 days and the lowest IC50 values for mean shoot length at 7 days in wheat, which can be used for toxicity prediction and early diagnosis of petroleum-contaminated soil.

Alternative Feed Sources for Vermicompost Production

Locally-available materials could be used to address soil fertility constraints. Vermicomposting is a promising technology where various organic materials are converted into processed compost by earthworms. This study evaluated local feed sources and their potential for vermicompost production. The vermicompost production was carried out in the plastic container under a roofed and net-sided production house. The plot design was laid out in Completely Randomized Design (CRD) with nine replications. Vermiculture feedstock treatments were cow manure (CM) and three cow manure and alternative feed stock treatments (75:25 on a dry basis) that included water hyacinth (WH), used coffee grounds (coffee), or Azolla. The results showed that cow manure combined with Azolla tended to produce more vermicompost after four weeks, but post-harvest earthworm weight was lower. The cow manure treatment produced higher earthworm weights. However, the earthworm population was not influenced by feed sources. The chemical characteristics of vermicompost were not different among feed source ratios or combination. A comparison of the feed stock material before and after vermiculture composting show that EC and total P increased in the compost, total K, organic C and the C:N ratio decreased, but pH and Total N remained constant.

Removal of phosphorus from water using calcium-rich organic waste and its potential as a fertilizer for rice growth

Mussel shell (MS) waste was upcycled as value-added products, namely an adsorbent for P removal from lakes and P fertilizer after adsorbent use. Calcination improved the P adsorption capacity of MSs by changing the mineral structure from calcite (CaCO3) to lime (CaO) and portlandite (Ca(OH)2) and enhancing the elution amount of Ca2+. The MSs were calcined at the optimum calcination temperature of 800 °C (CMS-800) and then used to adsorb P in aqueous solution to form hydroxyapatite (Ca5(PO4)3(OH)). The pseudo-first-order and Langmuir models were well fitted to kinetic and equilibrium P adsorption by CMS-800. The maximum adsorption capacity of CMS-800 obtained from the Langmuir model was 66.70 mg/g. The adsorption amount of 88.40 mg/g at a pH of 3 decreased to 58.48 mg/g at a pH of 7, but increased again to 91.16 mg/g at a pH of 11. Anions coexisting in the P solution reduced the amount of P adsorbed by CMS-800; their effects were in the order of SO42- > HCO3- > > Cl- > NO3-. Two centimeters of CMS-800 in a fixed-bed column showed a P removal rate of 50.92% (4.29 mg/g) until saturation. The initial and final earthworm weights after the addition of CMS-800 and P-adsorbed CMS-800 (P-CMS-800) did not show a statistically significant difference. P-CMS-800 was present mainly in the form of Ca-bound P and residual P, which accounted for 43.07% and 55.64% of the total, respectively. The medium level of P-CMS-800 (0.73 g/kg soil) promoted plant growth by increasing major agronomic traits. CMS-800 can be used as an effective adsorbent to remove P from water, and P-CMS-800 can be used as a substitute for P fertilizer in rice cultivation.

VERMICOMPOSTING

Vermicomposting is a method of composting by using earthworms, in this process earthworms eat biodegradable wastes (Such as vegetables and fruits peels), and they break down these natural materials into organic fertilizer. Vermicompost is generally used for organic farming and also maintains the health of the soil. The amount of Nitrogen is more as compared to Phosphorus and Potash in vermicompost. Vermicompost doesn’t harmful to the soil and also helps in increasing the nutrient content of the soil. The life of earthworms is 4 - 8 years depending upon the species. The nutrients contents like Nitrogen, Phosphorus, Potash, Calcium, Magnesium, Iron, Manganese, and Zinc are found in vermicompost. Endozoic earthworms are found in a deep layer of soil and they eat 90 % soil and 10 % organic matter. Epizoic earthworms are found on the surface ofthe soil and they eat 10 % soil and 90 % organic matter. Epizoic earthworms are famous for vermicomposting because they produce more vermicompost as compared to Endozoic earthworms. The weight of earthworms is between 0.5 to 0.6 g. one kg earthworm produces 0.8-7 kg vermicompost per day.

Effect of chemical and bio-fertilizers on the life table attributes of Eisenia fetida

Earthworms are important soil invertebrates and play an important role in improving soil quality. Indiscrete use of chemical fertilizers poses a threat to soil quality. Alteration in the soil chemistry is known to negatively impact the macrofauna of soil, especially, epigeic earthworms. The study aimed to understand the effect of chemical and biological fertilizers on the life table attributes of earthworm, Eisenia fetida. Laboratory adapted E. fetida were reared on artificial soil supplemented with chemical fertilizers, Urea and DAP, and biofertilizers, vermicompost and Rutoz®.It was observed that the presence of urea in soil proved to be detrimental to the biomass accumulation, life span, as well as reproductive potential of the earthworms. Application of urea to the soil harbouring earthworms reduced the weight of individual earthworms from 286±14.24 mg in the control group to 242±12.047 mg as soon as 15 days of the application, while the DAP diminished the earthworm weight to 272±13.54 mg. The effect was more pronounced on the total biomass of the culture owing to the high toxicity of urea. The total mass diminished to one-third,i.e., 1.02±0.05 g on Day 60 as compared to the corresponding control (3.46±0.172 g). The urea and DAP treatment decreased the percent survival of the earthworms by 70% and 40%, respectively.On the other hand, the bio-fertilizers had a positive effect on the earthworms and the biology is comparable to that of the control group. To the best of our knowledge, this is the first attempt to understand the effect of chemical fertilizers on the survival and reproductive fitness of the worms.

Biochemical phosphorus transformations in a calcareous soil as affected by earthworm, cow manure and its biochar additions

Application of raw or char material may modify the influence of earthworm activity on soil phosphorus (P) transformation. The purpose of this study was to investigate the effect of cow manure or cow manure biochar addition and its interaction with earthworm on organic (Po) and inorganic (Pi) P fractions, alkaline phosphatase activity and P-solubilizing bacteria (PSB) in a calcareous soil of semi-arid region. For this purpose, the soil was amended with cow manure and its biochar in 4 levels (0, 1, 2 and 5%) in the absence and presence of earthworm (Eisenia fetida). The treatments were then incubated for 90 days. The monitoring of earthworms was also carried out after 30 and 90 days incubation. The results showed an increase in weight of earthworms in control and cow manure amended soils at both incubation times. However, application of cow manure biochar resulted in mortality and an initial weight loss of earthworms (36–85%) at 30 days incubation. This negative effect decreased over time, so that the earthworms recovered in 1% biochar amended soil. Amendment additions increased proportion of NaHCO3-Pi and NaOH-Pi but decreased proportion of HCl-Pi, residual-P, NaOH-Po and HCl-Po, making P more available in soil. The impact of cow manure biochar on the NaHCO3-Pi and NaOH-Pi fractions was stronger than that of cow manure. Earthworm decreased the proportion of Pi fractions but increased the proportion of Po fractions, indicating a transformation of P from Pi to Po forms. Alkaline phosphatase activity and PSB number were also increased as affected by earthworm and amendment (especially cow manure) additions. No significant interaction between earthworm and amendment additions was observed (p < 0.05), indicating that the influence of earthworm on P transformations was not dependent on amendment additions. Overall, we concluded that biochar can be useful for the amendment of semi-arid calcareous soil in terms of P availability, but the negative response of earthworms to biochar and its effect on other soil processes should be taken into consideration.

Performa Cacing Lumbricus rubellus terhadap Penambahan Tepung Cangkang Telur sebagai Media

Lumbricus rubellus is one of earthworm species that has been cultivated because its utility as feed for livestock and fish. The culture media for earthworms are mainly manure and compost. The purpose of this research was to observe the performance of Lumbricus rubellus given eggshell powder in different types and levels. This study used commercial eggshell flour and homemade eggshell flour with different levels (10%, 20%, 30%) mixed with cow dung as a medium. The results of the study showed that the addition of eggshell flour (commercial and homemade) as much as 10% showed a higher earthworm weight gain than other treatments but the cocoon production of the treatment was lower than the control (0% eggshell flour).

Optimum Castor Meal Application in the Cultivation of Pak Choi (Brassica chinensis L.) with Toxicity Survey for Earthworms (Eisenia andrei)

In Taiwan, castor meal (CM) is often used by farmers as an organic fertilizer for the supplement of plant nutrition. It can rapidly increase nitrogen availability for crops. However, the excessive application of CM will affect the ecosystem. This study was conducted to evaluate the optimum concentration of CM that can be used as a fertilizer for balancing crop production and soil ecosystem health (by considering earthworms). Pak choi was selected for the experiment. A randomized block design with three replications was used, with treatments consisting of five concentrations of CM (namely 25, 50, 100, 150, and 200 kg/0.1 ha) and fermented livestock compost 800 kg/0.1 ha, represented as CM25, CM50, CM100, CM150, CM200, and LC800, respectively. The results revealed that soil properties, leaf nutrient concentration, and plant traits, namely plant diameter, plant height, and fresh and dry root and shoot matter, improved with the increasing concentrations of CM, and CM100–CM200, and led to the highest production of pak choi which was equivalent to that with LC800. However, the weight of earthworms decreased as CM concentrations increased. The weight of earthworms was similar between CM25, CM50, CM100, and LC800. In conclusion, given the characteristics of high nitrogen as a fertilizer, the optimal dose of CM was 100–150 kg/0.1 ha for obtaining a balance between crop production and ecosystem safety.

Conversion of spent coffee grounds into vermicompost

The present study was focused on vermicomposting of spent coffee grounds (SCG) and its mixtures with straw pellets. The process was evaluated in terms of biological and physico-chemical properties. The greatest number and biomass of earthworms was found in the treatment with 25% vol. SCG + 75% vol. straw pellets. In this treatment, the upper youngest layer exhibited 1.6-fold and 4.5-fold greater earthworm number and biomass, respectively, than the bottom oldest layer. Earthworm weight decreased in direct proportion to the layer age. The oldest treatment layer was characterized by lesser contents of fungi and six hydrolytic enzymes, compared to the younger layers. Further, the oldest treatment layer had suitable agrochemical properties. Earthworms were able to substantially reduce the caffeine stimulant content, which is considered the most representative pharmaceutically active compound.

Toxicokinetics of hydrophobic organic compounds in oligochaeta: A critical review

Toxicokinetic studies appertain to the fundamental research of soil bioavailability. However, the research outcomes of aspects influencing uptake and elimination of hydrophobic organic compounds have not been summarized so far. In our review, a recapitulation of available toxicokinetic data (i.e. experimental conditions, if the steady state was reached, uptake and elimination rate constants, and bioaccumulation factors) is presented in well-arranged tables. Further, toxicokinetic models are overviewed in the schematic form. In the review, the required information could be quickly found and/or the experimental gaps easily identified. Generally a little is known about the effects of soil properties other than soil organic matter. Limited or no data are available about soil treatment, food supply during laboratory exposure, and metabolization in oligochaeta. The impact of these factors might be important especially for arable soils with typically low organic matter content but high consequences on humans. Besides these circumstances, other uncertainties between published studies have been found. Firstly, the scientific results are provided in heterogenous units: bioaccumulation factors as well as the rate constants are reported in dry or wet weight of soil and earthworms. The steady state is another critical factor because the time to reach the equilibrium is influenced not only by soil and compound characteristics but for example also by aging. Nevertheless, toxicokinetic studies bring irreplaceable information about the real situation in soil and our review help to define missing knowledge and estimate the scientific priorities.

Оценка влияния сидератов на биологические свойства чернозема оподзоленного в звене полевого севооборота

Abstract. The purpose is to study the effect of various siderates on the biological properties and yield of spring barley. Methods. Тhe experiment was carried out on podzolized chernozem in 2017–2018 in the forest-steppe zone of the Middle Urals. The green mass of the siderates was taken into account manually, and barley grain by combine was carried out. Soil moisture was determined by the thermostatic-weight method. The number and mass of earthworms were determined from the registered area. The microbiological activity of the soil was determined by the method of linen cloths. Scientific novelty. For the first time, the effect of various siderates on the yield of spring barley and the microbiological activity of the soil, the number and mass of earthworms was compared on podzolized chernozem. Results. The effect of various siderates: peas + oats, winter rye, spring rapeseed, white mustard, fodder beans on the microbiological activity of the soil, the number of earthworms and the yield of spring barley in the link of the field crop rotation – sideral steam – spring barley was studied. The largest green mass of green manure was plowed into the soil in the following variants: fodder beans (41.2 t/ha) and peas + oats (36.4 t/ha). In the variant with the planting of fodder beans, the highest microbiological activity of the soil was observed (71 %). Studies of the number of earthworms showed that their number was 24 % higher in the mustard variant compared to the control. However, the mass of the soil they processed in the peas + oats variant (138 g/m2) was maximum and exceeded the mass in other versions by 11–27 g/m2. The highest yield of barley was also obtained in the variant with the incorporation of feed beans – 2.87 t/ha, which is 0.26–0.69 t/ha higher than the rest. Increasing the microbiological activity of the soil in the variant with the incorporation of feed beans increased the yield of barley. The increase in the plowed green mass in the variants did not affect the increase in the number and weight of earthworms.

Effects of biochar and thermally treated biochar on Eisenia fetida survival, growth, lysosomal membrane stability and oxidative stress

Despite its known positive impacts when added to soil, the negative effects of biochar on earthworms are not fully understood. Here, we investigated the toxicity of nine biochars of three feedstock origins, animal (cow dung), plant (corncob) and microorganism (sewage sludge), produced at three pyrolysis temperatures (350 °C, 550 °C and 750 °C) on earthworms. Vermitoxicity was first assessed using acute toxicity test, neutral red retention time (NRRT) assay and oxidative stress response assay. Furthermore, we evaluated whether the thermal treatment of biochars could reduce their vermitoxicity using an acute toxicity assay. We found that, according to LC50 and earthworm weight loss, cow dung biochar was more toxic than corncob or sewage sludge biochar; thus, production feedstock is apparently important to biochar vermitoxicity. Furthermore, NRRTs indicated cow dung biochar disrupted lysosomal membrane stability in earthworm coelomocytes, providing further evidence for the toxicity of this biochar to earthworms. Disturbed antioxidant enzyme activities and elevated malondialdehyde content showed that earthworm suffer oxidative stress, also implying a potential vermitoxicity. However, thermal treatment of cow dung biochar substantially improved its LC50 and decreased earthworm weight loss, implying that the PAHs in this biochar might be damage factors and that heating could reduce the potential toxicity of biochar. Besides, NRRT assay was first used to evaluate the effects of biochar on earthworms and clear dose-effect relationships indicated that NRRT assay might be a useful tool for assessing the potential negative effects of biochar. Overall, given the different effects of various biochars, including toxicity, reported here, our findings will help improve understanding of biochar vermitoxicity mechanisms, serve to improve biochar ecological risk assessments and provide a reference for the proper application of biochar amendments.

A Strip-Till One-Pass System as a Component of Conservation Agriculture

Conservation agriculture has three main pillars, i.e., minimum tillage, permanent soil cover, and crop rotation. Covering the soil surface with plant residues and minimum mechanical soil disturbance can all result from introducing a strip-till one-pass (ST-OP) system. The aim of this study was to determine the impact of the ST-OP technology on the management of plant residues, soil properties, inputs, and emissions related to crop cultivation. We compared the effect of a ST-OP system against conventional tillage (CT) using a plough, and against reduced, non-ploughing tillage (RT). Four field experiments were conducted for evaluating the covering of soil with plant residues of the previous crop, soil loss on a slope exposed to surface soil runoff, soil structure and aggregate stability, occurrence of soil organisms and glomalin content, soil moisture and soil water reserve during plant sowing, labour and fuel inputs, and CO2 emissions. After sowing plants using ST-OP, 62.7–82.0% of plant residues remained on the soil surface, depending on the previous crop and row spacing. As compared with CT, the ST-OP system increased the stability of soil aggregates of 0.25–2.0 mm diameter by 12.7%, glomalin content by 0.08 g·kg−1, weight of earthworms five-fold, bacteria and fungi counts, and moisture content in the soil; meanwhile, it decreased soil loss by 2.57–6.36 t·ha−1 year−1, labour input by 114–152 min·ha−1, fuel consumption by 35.9–45.8 l·ha−1, and CO2 emissions by 98.7–125.9 kg·ha−1. Significant favourable changes, as compared with reduced tillage (RT), were also found with respect to the stability index of aggregates of 2.0–10.0 mm diameter, the number and weight of earthworms, as well as bacteria and fungi counts.