Vermicompost Soil Research Articles

The Age-Induced Quality Shift of Vermicompost Influenced the Biodegradation Kinetics in Soils

ABSTRACT A study was conducted to identify the effects of aging on the biodegradability of vermicomposts in soil. Two solid wastes, including cow manure (CM) and wheat residues (WR), were subjected to the vermicomposting. The products of the various ages were mixed with Lavark and Langroud soils and incubated for 45 days. Results indicated that the aging effects led to an increase in the lignin (LG) content. Potentially, mineralizable C was decreased from 5308 mg C kg−1 for fresh substrates to 1643 mg C kg−1 for aged CM vermicompost in the Lavark soil. The decreasing trend was also observed for the Langroud soil. Similar behavior was also shown for the soils when treated with WR vermicomposts of different ages. The age of vermicomposts was negatively correlated with potentially mineralizable C as well as LG and C/N ratio. Multiphase decomposition was observed, in particular when the products of the early ages were used. The aging of CM and WR induced a decrease in the number of decomposition phases. Overall, by aging, the less biodegradable fraction (lignin) accumulates, and the patterns of decomposition tend to decrease the number of decomposition phases or decrease the last phase biodegradation rate constant.

Effect of Compost and Vermicompost Amendments on Biochemical and Physiological Responses of Lady’s Finger (Abelmoschus esculentus L.) Grown under Different Salinity Gradients

In the coming decades, the pressure to use saline water will increase as most of the natural resources with good water quality are being depleted. In order to avoid more stress on the soil plant system, a better understanding of the type of amendments and their integration with the irrigational water quality of any location-specific region is essential. Utilizing salt-affected lands in the best way possible will facilitate food security for the growing human population. An experiment was conducted with the Abelmoschus esculentus L. plant, irrigated with saline water having different NaCl gradients (0, 50, 100 and 150 mM), to evaluate the biochemical and physiological responses under different salinity gradients. Additionally, the effect of compost and vermicompost amendments in soil on plant responses to the changing salinity of irrigated water was observed. The results suggested that the addition of compost and vermicompost in soil not only suppressed the adverse impact of salinity in plants but also increased soil nutrients (TKN, OC, avail. P, avail. K and avail. Ca contents). Moreover, some biochemical parameters and plant growth parameters showed better traits in such manure-amended setups. The enhancement of proline, phenol, ascorbic acid and lipid peroxidation contents in the leaves of Abelmoschus esculentus L. under high salinity levels suggests some secondary metabolite-mediated response possibly due to stress caused by soil salt accumulations. In summary, crop production could be efficiently maintained in saline water-irrigated areas after amending the soils with appropriate organic manure.

Optimization of Engineering and Process Parameters for Vermicomposting

Urbanization and population rise considerably increase the generation of solid wastes. The recycling of solid wastes through vermicomposting is a sustainable approach. The current study aimed to investigate the effect of earthworm (Eisenia fetida and Eugilius euganiae)-processed/mixed solid waste manure (vermicompost) on the development, productivity, and chemical characteristics of chili and brinjal in different wooden reactors (R). A mixture of palash leaf litter, biogas slurry, food wastes from a hostel kitchen and households, and municipal solid waste (MSW) were used during the study. The effects of different reactors; process parameters; earthworm cultures, such as R1–R9 with different widths and lengths at a constant height (30 cm); pH, salt, and moisture content; temperature; C:N ratios; N, P, K, and pathogen content; and the type of mono/-polyculture on vermicompost were tested with respect to chili and brinjal production. The average net increase in the worms’ zoomass in reactor R1 at different mixed worm densities (E. fetida + E. eugeniae) under optimum conditions was observed. Compared to a monoculture reactor, the yield of both chili and brinjal were significantly greater in the polyculture reactor with vermicompost soil.

Effect of Temporal Variation in Mineralization of Nutrients through Sewage Sludge, Farm Yard Manure and Vermicompost in Soil

Soil amendment by organic matter (O.M.) has been widely accepted as an efficient nutrient-management technique in agriculture. The study was conducted as pot culture experiment at the Rajiv Gandhi South Campus, Barkachha Banaras Hindu University (B.H.U.) Mirzapur, which is located in the Vindhyan zone of Mirzapur district at 25º 10” latitude, 82º 37” longitude with an altitude of 427 meters above the sea level. The soils of the study region are mostly having poor fertility and shallow depth. Different sources of organic manures Sewage Sludge (S.S), Farm Yard Manure (FYM) and Vermi-Compost (V.C.) with different doses (10, 20 and 30 grams) were applied in pot along with soil and were incubated for 90 days. Required amount of water was added to soil in order to keep it moist as and when required. pH, electrical conductivity(E.C) , O.M. and nutrient content (N, P, K and S) had shown significant changes due to different treatments applied in soil. Applications of organic amendments in this study indicated considerable changes in the basic soil physio-chemical properties, different levels of available nutrient and their release pattern. With increase in doses of S.S and V.C. soil pH also increased but, it was decreased with increase in doses of FYM. Increase in the dose of S.S., F.Y.M. and V.C. had increased the E.C. and O.M. of soil. The available N content decreased with increase in the incubation interval. The available P increased from 30 Days After Incubation (DAI) to 60 DAI but it decreased at 90 DAI. Availability of S content increased with increase in duration of incubation period.

EFFECT OF VERMICOMPOST ASSOCIATED WITH MYCORHIZAL FUNGI ON THE GROWTH OF EGGPLANT IN ORGANIC GREENHOUSE AGRICULTURE

<p><strong>Background</strong>. In West Africa, the eggplant crop participates in the fight against rural poverty, hunger and malnutrition due to their higher nutritional contents. However, this crop is faced with several constraints including poor soils and low yielding cultivars. It is known that mycorhization of plants improves plant nutrition while preserving them from certain pests. <strong>Objective.</strong> To evaluate the combination of mycorhization and vermicompost effect on eggplant plants growth and yield. <strong>Methodology.</strong> A consortium of arbuscular mycorrhizal (AM) from forest soils was trapped using maize roots and used as inoculum for eggplant, Djamba F1 variety. A trial using this inoculum combined or not to vermicompost was carried out for 90 days under a greenhouse. Selected soil properties, eggplant growth and yield indicator were recorded at the end of trial. <strong>Results.</strong> As expected, soil vermicompost alone or combined to inoculum displayed an increase of soil parameter such as pH, exchangeable base cations, total organic matter, total nitrogen compared to control and soil with AM alone. Soil with AM alone had a limited impact on the growth and yield of eggplant. In contrast, all treatments including vermicompost (vermicompost alone and vermicompost + AM) showed a significant increase of eggplant growth parameters and yield’s indicators. <strong>Implications.</strong> These results highlighted a need to carry out a screening of mycorrhizal fungi from eggplant production areas to isolate and identify the efficient strains of mycorrhizal fungi for symbiosis with eggplant under tropical conditions. <strong>Conclusion. </strong>The vermicompost significantly improved the growth of the eggplant. Its coupling with a consortium of spores of the genera<em> </em>results in better plant growth and yield. This combination has a significant effect on the studied parameters (height, crown diameter, biomass and yield). </p>

Effect of vermicompost soil additive on growth performance, physiological and biochemical responses of tomato plants (Solanum lycopersicum L. var. Firenze) to salt stress

Vermicomposting is increasing used to process food, sewage and other organic wastes through the breakdown by earthworms. Vermicompost addition to soils can improve plant growth through increasing the accessability of nutrients and lowering levels of contaminants found in other compost products. This study examins the effect of vermicompost on salinity tolerance in tomato plants (Solanum lycopersicumL., var. Firenze) via greenhouse pot experiments. Plants were grown on 4 substrates designated by letter identifiers: A control, “T” with 100% organic soil; a vermicompost treatment “Vc” was 80% organic soil + 20% Vermicompost; a compost treatment “C” was 80% organic soil + 20% Compost; and a mixture treatment “M” was 80% organic soil + 10% Vermicompost+ 10% Compost. The four treatment groups were exposed to 3 NaCl concentrations (0, 50 and 150 mM); the experimenta; design within the greenhouse was complete randomized block. The plants’ response to salinity stress was evaluated through morphological (shoot length, stem diameter, leaves number, root length, shoot and root fresh and dry weight), physiological (Chla, Chlb and Carotenoid) and biochemical (malondialdehyde (MDA) and catalase (CAT)) parameters. All measured parameters were significantly different between the four soil treatments. Plants grown on Vc substrate showed an improved growth and a better resistance to salinity stress. Analyzed parameters were positively influenced by the contribution of the organic matter (Vermicompost, compost and a mixture of the two) which plays a role in the slow, consistent release of mineral elements and provides soluble nutrients to reduce abiotic stresses. In conclusion, vermicompost could be a relevant method for reducing salt stress on tomato plants growth, addressing the challenges of growing food crops in drier, more saline contaminated envvironments.

English

Greenhouse experiments were conducted to investigate the effects of various vermicompost amendments on growth responses and nutrient content of kale (Brassica oleracea Acephala group), radish (Raphanus sativus), and tomato (Solanum lycopersicum L), using a completely randomized design with three crop species, four vermicompost treatments and four replications. The twelve treatment combinations consisted of vermicompost levels of 0, 5, 10, and 15% (v/v) and three crop species, kale, radish and tomato. Plants were grown in pots containing soil in which the respective vermicompost levels were incorporated. Three seeds of each species were sown in each pot and seedlings were thinned to one per pot each, approximately two weeks after germination. Plants were supplied at regular intervals with 300 ml of water to maintain field capacity. Plant height, leaf chlorophyll, stem diameter, and leaf expansion rates were collected at weekly intervals beginning three weeks after planting. Plants were harvested at respective maturity dates, and fresh and dry weights as well as total yield were taken. Root, leaf and fruit samples were collected to determine phenolic and ascorbic acid content. Vermicompost soil amendment significantly increased plant height of kale and radish compared to the control but had no significant effect on the height of tomato plants. Leaf chlorophyll content was also greater among plants receiving vermicompost amendments except that of kale which declined at highest amendment level.  Fresh and dry weight of kale increased with levels of vermicompost amendments with the magnitude of increase being greater between the control plants and those amended with 5%. Tap root yield of radish was highest among plants amended with 15% vermicompost but yield was similar among amended treatments. Regardless of the treatment, stem diameter was highest in the last few weeks of measurements. Total phenolic content tended to decrease regardless of species with increasing vermicompost levels and vitamin C increased initially up to 10% level for kale and declined thereafter, while there was a steady decline in radish. These results show that vermicompost amendments above 10% may adversely affect plant height and leaf chlorophyll content, while enhancing overall biomass production, and that phenolic and vitamin C responses varied based on vermicompost levels. Keywords: Compost, sustainability, soil, organic matter, chlorophyll.

Biochar and vermicompost soil amendments reduce root rot disease of common bean (Phaseolous Vulgaris L.)

Biochar and vermicompost soil amendments reduce root rot disease of common bean (Phaseolous Vulgaris L.)

Comparison of the effects of compost and vermicompost soil amendments in organic production of four herb species

ABSTRACT The aim of this study was to compare the effects of using compost and vermicompost as soil amendments in organic herb production, using four herb species (Dracocephalum moldavica L., Melissa officinalis L., Nepeta cataria L. and Thymus vulgaris L.) as model plants. Plants were cultivated in a greenhouse in containers filled with soil from an organically certified field and that had been amended with equal rates of cow manure compost or vermicompost [0%, 10%, 20% and 30% (v/v) for M. officinalis and N. cataria, and 0%, 20%, 30%, and 40% (v/v) for D. moldavica and T. vulgaris]. The four herbs showed different sensitivity to the incorporation of the organic amendments, with the optimum rate differing between the species: 20% was shown to be optimum for both amendments in the case of M. officinalis and N. cataria, and 20% for compost and 30% for vermicompost in the case of D. moldavica and T. vulgaris. However, at identical amendment rates, the vermicompost treatment resulted in higher plant biomass compared with the compost. The organic amendments tended to increase the concentration of K+ in the leaf tissue in all species. The NO3 – concentration in the leaf tissue tended to increase with increased rates of the organic amendments, but both amendment-specific and species-specific effects were evident. It was concluded that the use of vermicompost was superior to that of compost for organic herb production in containers.

Biocontrol and plant growth-promoting properties of Streptomyces isolated from vermicompost soil

Thirty isolates of Streptomyces like colony isolated from vermicompost soils were assessed for their antagonistic and plant growth-promoting (PGP) activities. Five isolates having the best inhibitory activity against five plant pathogenic fungi, Colletotrichum gloeosporioides, C. musae, Fusarium sp. TFPK201, Fusarium sp. Foc 1699 and Pestalotia sp. were subsequently identified by 16S rDNA analysis. The selected isolates were classified in the genus Streptomyces and given the name of Streptomyces spp. SEF1, SEF8, SEF47, SEF48 and SEF49, respectively. Then, their PGP and antifungal activities were evaluated. The results showed that the selected isolates were able to produce IAA, siderophore, and amylase. Production of IAA was ranged from 14.06 to 16.59 µg/mL. The highest siderophore production was found in the isolate SEF48. Only isolates SEF47, SEF48, and SEF49 showed amylolytic activity. The culture filtrate from the tested Streptomyces spp. inhibited the fungal mycelial growth and suppressed conidial germination, but their inhibition ability was different. Interestingly, the application of all selected culture filtrates before disease infection significantly decreased tomato Fusarium wilt disease incidence and severity. However, only Streptomyces sp. SEF47 could significantly reduce the disease incidence and severity when it was applied after the disease infection. Moreover, this research found the plant growth-promoting ability of the culture filtrate of selected isolates on tested tomatoes. The Streptomyces sp. SEF47 provided a significant ability for controlling all tested plant pathogenic fungi and promoting plant growth. Therefore, Streptomyces sp. SEF47 could be considerable biocontrol and PGP agent used in sustainable agriculture.

Effect of Black Pointed Seed and Vermicompost on Leaf and Seed Infection of Wheat caused by Bipolaris sorokiniana

An experiment was conducted to find out the effect of different levels of black pointed seed and vermicompost in soil on leaf blight (Bipolaris sorokiniana) severity, yield attributes and seed health status of harvested seed of wheat, cv. Shatabdi. In the field experiment in RCBD design with 18 treatments, the maximum (114.3 and 124.0) emergence of seedling was recorded from apparently healthy seed treated with Provax 200 @ 0.25% sown in soil amended with vermicompost @ 1.5 t ha−1 after 7 days and 15 days of sowing, respectively. Leaf blight severity (0–5 scale) on flag leaf and penultimate leaf in flag leaf stage, panicle initiation stage, flowering stage, milking stage and hard dough stage were recorded the maximum when 25% black pointed seeds in weight basis were sown without vermicompost. The treatments showed significant variations on number of grains per ear of different severity grades (0–5). Significantly higher 1000 seeds weight (42.70g), grain yield (3.66 t ha−1) and straw yield (4.33 t ha−1) were recorded from the plants germinated from apparently healthy seed treated with Provax 200 @ 0.25% sown in soil with of vermicompost @ 1.5 t ha−1. In laboratory experiments, decreasing trend of germination, normal seedling percentage, shoot length, root length, seedling weight and vigor index (VI) of the seedlings emerged from increasing levels of black pointed seed sown revealed that apparently healthy seed treated with Provax 200 @ 0.25% sown with vermicompost @ 1.5 t ha−1 and showed promising results in respect of disease severity on leaf and quality seed production.

Evaluation of photosynthesis, physiological, and biochemical responses of chickpea (Cicer arietinum L. cv. Pirouz) under water deficit stress and use of vermicompost fertilizer

One goal in the face of drought stress conditions is to increase growth and yield through the reduction of negative effects of stress. Vermicompost can play an effective role in plant growth and development and in reducing harmful effects of various environmental stresses on plants due to its porous structure, high water storage capacity, having hormone-like substances, plant growth regulators, and high levels of macro and micro nutrients. This study considered the physiological, biochemical, and photosynthetic responses of the chickpea to different combinations of vermicompost and water stress in a greenhouse environment. Two factors were involved, addition of vermicompost to soil at four ratios: control (100 wt% (weight percentage) soil); 10 wt% vermicompost+90% soil; 20 wt% vermicompost+80 wt% soil; 30 wt% vermicompost+70 wt% soil weight percentage, and treatment of water stress at three levels including 75, 50, and 25% of field capacity. The results showed that vermicompost had a significant effect on all traits under stress and non-stress conditions. Application of vermicompost in soil, especially at the levels of 20 and 30 wt% significantly increased all studied traits under non-stress conditions. Under moderate stress conditions, vermicompost at 30 wt% treatment resulted in a significant increase in the photosynthetic pigments, CO2 assimilation rate, internal leaf CO2 concentration, transpiration, the maximal quantum yield of photosystem II (PSII) photochemistry (Fv/Fm), concentrations of Ca and K in root and leaf tissues, proline and soluble protein contents in root tissues. Peroxidase (POX) and catalase (CAT) enzyme activities decreased significantly with increasing proportions of vermicompost, but the activity of superoxide dismutase was not significantly different. In conclusion, the above results showed that vermicompost fertilizer had a positive effect on physiological, biochemical, and photosynthetic responses of chickpea under non-stress and moderate stress conditions, but no positive effect was determined under severe water stress.

Evaluation of vermicompost fertilizer application on growth, nutrient uptake and photosynthetic pigments of lentil (Lens culinaris Medik.) under moisture deficiency conditions

ABSTRACTVermicompost can play an effective role in plant growth and also in reducing harmful effects of various environmental stresses on plants due to its porous structure, high-water storage, having hormone-like substances and also high levels of macro and micro nutrients. Application of vermicompost in soil, especially at the levels of 15 and 25 Wt% significantly increased all studied traits under non-stress conditions. Under temperate and severe stress conditions, vermicompost at 25 Wt% treatment resulted in a significant increase in plant height (+10% +21%), number of pod (+44% +65%), root dry weight (+63% +66%), shoot dry weight (+50% +89%), leaf area (+6% +7%), root area (+65% +35%). The leaf calcium (Ca) (+62% +67%), leaf potassium (K) (+39% +45%) and root Ca (+33% +34%) under temperate and severe stress, increased using of 25% vermicompost. In conclusion, we suggested that application of vermicompost had a positive effect on lentil under moisture deficit stress.

Production of Soil Block Seedlings in Plug Trays for Mechanical Transplanting

ABSTRACTEstablishing vegetables in the field using mechanical transplanters with only plant metering devices requires transplants with heavy soil blocks around the roots. An investigation was conducted to study the effects of amount of vermicompost in a soil-based potting mix and initial compaction of the mix on growth of seedlings and soil block strength for mechanical transplanting. Seedlings of Tomato (Solanum lycopersicum L.), Eggplant (S. melongena L.), and Chili pepper (Capsicum frutenscens L.) were produced in two seasons in plastic plug trays with a potting medium in which vermicompost made up 20%–50% by volume in 60 and 100 cc tray cells. Potting mix with 20% vermicompost by volume in soil in 100 cc cells produced good growth of tomato and chili pepper transplants in season 1. Potting mix containing 20%–30% and 20%–40% vermicompost in soil in 100 cc cells produced good growth of tomato and chili pepper transplants, respectively, in season 2. Potting mix with 30%–40% and 30% vermicompost by volume in soil in 100 cc cells produced good growth of eggplant seedlings in seasons 1 and 2, respectively. The effects of initial compaction of potting mix on water requirement, plant height, and soil block strength was studied for the production of tomato seedlings. Potting mix with 30% vermicompost in 100 cc tray cells and initially compacted to the dry density of 0.88–0.90 g·cm−3 was most suitable for production of seedlings of sufficient height and soil block strength for mechanical transplanting.

Vermicompost Affects Soil Properties and Spinach Growth, Physiology, and Nutritional Value

The use of vermicompost to improve soil fertility and enhance crop yield has gained considerable momentum due to its contribution to agroecological sustainability. Short-term (35 days after transplanting) effects of vermicompost, applied either as a soil amendment (5% and 10%, v/v) or a drench (40 mL of vermicompost extract at 0, 14, 21, and 28 days after transplanting), on soil properties and spinach plants (Spinacia oleracea L.) were evaluated in a greenhouse. After harvesting, the amendments left high residual levels of nutrients, organic matter and carbon, and increased soil cation exchange capacity (CEC) and water-holding capacity (WHC). Drench treatment of unamended soil increased soil nutrients, CEC, and WHC. All vermicompost treatments, especially amendment at 10% rate, increased leaf number, area, fresh and dry weight (FW and DW), shoot FW and DW, root DW, and water use efficiency (WUE). Vermicompost increased leaf chlorophyll content, and photochemical efficiency, yield, and electron transport rate (ETR) of mature leaves, as well as increased leaf succulence, and carotenoid, protein, and amino acid content. Vermicompost soil amendment reduced phenolics and flavonoids, leading to lower antioxidant capacity, whereas drench treatment only decreased betacyanin content. Vermicompost improved soil fertility, prompted leaf production, delayed leaf senescence, and enhanced growth of spinach. It also favorably influenced spinach quality by increasing leaf succulence and carotenoid, protein, and amino acids content, although it, as soil amendment, reduced flavonoid content leading to low antioxidant capacity.

Long-term electricity production from soil electrogenic bacteria and high-content screening of biofilm formation on the electrodes

This study was conducted to determine the existence of soil bacteria in soil by soil microbial fuel cell (SMFC). The main objectives were (1) to differentiate the type of soil which will influence the electricity production, (2) to demonstrate the impact of different volume of soil in the MFC and feeding MFC for long-term electricity production, and (3) to conclude that electricity production is directly proportional to the biofilm formation on the anode surface. MudWatt kits were purchased from Keego Technologies USA, and 22 identical SMFCs were designed to study the electricity production from agricultural soil (S1) and vermicompost soil (S2). Ten milliliters of bioslurry is fed in SMFC to study the stability of electricity production at different stages. Microbes were isolated and characterized from the surface of the electrode. Biofilm analyses were done by high-content screening (HCS) system using 10 μl of acridine orange (100 μg/ml) at different stages of biofilm, and scanning electron microscopy is applied to confirm the matured biofilm on the surface of the anode. Application of bioslurry at different stages of electricity production conquers the normal energy recovery of the SMFCs and S2 soil with bioslurry sample produced the highest open circuit voltage (OCV) of 2.8 V (460 days) and S1 soil sample with bioslurry produced 1.7 V (364 days). The difference between SMFCs and MudWatt kits significantly confirms that increasing the volume of soil in the anode part increases the electricity production. The maximum OCV of S1 and S2 in MudWatt kits were 1.5 V (90 days) and 1.8 V (190 days), respectively. Increased volume of soil in our SMFCs produce maximum OCV of 1.8 V (S1 for 173 days) and 2.2 V (S2 for 240 days), and HCS analysis of biofilm at different stages reveals that electricity production is directly proportional to the biofilm formation. Thus, it was concluded that the nature of soil and soil bacterium is important for the electricity production, and S2 soil sample produces maximum electricity than the S1 soil sample. Feeding of SMFCs with bioslurry aids the long-term and stabilized electricity production in both the soil samples.

MFC with vermicompost soil: power generation with additional importance of waste management

Schematic representation of the series of events occurring in a MFC run with vermicompost soil.

Comparación de sustratos para producción de caoba Swietenia macrophylla King, con semillas colectadas del rio Michapan de Acayucan, Veracruz, México

Se realizó un estudio para evaluar el porcentaje de germinación, crecimiento, biomasa, humedad y materia orgánica, bajo diferentes sustratos en caoba Swietenia macrophylla King del rio Michapan. Fue empleado un diseño completamente al azar con cuatro repeticiones para el porcentaje de germinación, altura, diámetro, biomasa, retención de humedad y contenido de materia orgánica, los sustratos que se utilizaron para estas variables fueron: 1) tierra negra 100%, 2) lombricomposta 100%, 3) peat moss 100%, 4) tierra negra 50% + lombricomposta 50%, 5) tierra negra 50% + peat moss 50%, 6) lombricomposta 50% + peat moss 50%, y 7) tierra negra 33% + lombricomposta 33% + peat moss 33%. Los resultados del análisis de varianza mostraron diferencias estadísticas altamente significativas en los sustratos. Con base a la prueba de comparación de medias de Tukey se demostró que el mejor sustrato fue el tratamiento 7) tierra negra 33% + lombricomposta 33% + peat moss 33%, para obtener resultados favorables en % de germinación, crecimiento inicial, biomasa y características edáficas en especies forestales tropicales de caoba Swietenia macrophylla King.

Bottom-up effects mediated by an organic soil amendment on the cabbage aphid pests Myzus persicae and Brevicoryne brassicae

Earthworm-produced compost or vermicompost has been shown to increase resistance of plants to a variety of insect pests, but it is still unclear whether this resistance is dose dependent and whether the mechanisms responsible are the same for insect species with differing feeding habits and preferences. Therefore, we tested the effects of plants grown in various vermicompost concentrations (0, 20, 40, and 60%) on the preference and performance of generalist, Myzus persicae L., and specialist, Brevicoryne brassicae L. (both Hemiptera: Aphididae), aphid pests. Preference was evaluated with leaf disk (apterous) and whole plant (alate) choice assays. After 24 h of feeding, there was no significant negative effect on the feeding preference noted for apterae of either species of any of the treatments tested. To the contrary, apterae B. brassicae showed a significant preference for vermicompost treatments over control leaf disks. Alate M. persicae preferred alighting on control plants over vermicompost-grown plants, but B. brassicae showed no preference toward any of the treatments tested. Both aphid species deposited significantly more nymphs on control plants than on those grown in 20% vermicompost. Furthermore, plants grown in soil amended with 20% vermicompost significantly suppressed mass accumulation, as well as numbers of adults and nymphs of both aphid species compared to controls. These data clearly show that vermicompost soil amendments can significantly influence pest aphid preference and performance on plants and that these effects are not dose dependent, but rather species and morph dependent.

Vermicompost derived from different feedstocks as a plant growth medium

This study determined feedstock effects on earthworm populations and the quality of resulting vermicomposts produced from different types of feedstocks using different vermicomposting durations. Feedstock combinations (Kitchen Paper Waste (KPW), Kitchen Yard Waste (KYW), Cattle Manure Yard Waste (CMY)), three durations of vermicomposting (45, 68 or 90days), and two seed germination methods (with two concentrations of vermicompost) for radish, marigold and upland cress, served as the independent variables.The worms (Eisenia fetida) doubled their weight by day 68 in KPW and CMY vermicomposts and day 90 KPW vermicompost produced the greatest weight of worms. The direct seed germination method (seeding into soil or vermicompost–soil mixtures) indicated that KPW and KYW feedstocks decreased germination compared to the control, even in mature vermicompost. Seed germination was greater in the water extract method; however, most of the vermicompost extracts suppressed germination of the three seed species compared to the water controls. Vermicomposts from all three feedstocks increased leaf area and biomass compared to the control, especially in the 10% vermicompost:soil mix. Thus, seed germination and leaf area or plant biomass for these three species are contrasting vermicompost quality indicators.