Extraction of earthworm from soil by different sampling methods: a review

Earthworms are so closely incorporated into the soil structure that they are not calculated easily from the soil. Due to this property, their extraction from soil is tedious and time-consuming. Different methods have been used for their extraction from the soil, and efficiency of each method is affected by physical properties, viz., temperature and moisture of the soil. This study explored the advantage and disadvantage of different sampling methods for the extraction of earthworms such as hand sorting, octet method, formalin method, mustard extraction method, allyl isothiocyanate (AITC), and onion extraction method. Extraction efficiency of formalin is 20–60 times more as compared to hand sorting, but hand sorting gives satisfactory results for earthworms of more than 0.2 g live weight, and cocoons can also be recovered by this method. Octet method is effective in extracting anecic species and could easily be applied to site where chemical extraction is not a viable option. Extraction by mustard and AITC is simple, low cost, and more efficient for the extraction of deep-burrowing anecic species. The onion extraction solution is low cost and nontoxic which can be used as alternative to formalin. Like mustard, the onion solution is also inexpensive and not harmful to the earthworms and environment.     

Higher Pollution Episode Detection Using Image Classification Techniques

Image classification techniques have been applied to detect higher pollution episodes in modelled air pollution data. These techniques are widely used in video processing to find patterns in videos. An attempt for the first time has been made to apply these techniques by considering air pollution as continuous video frames as the spatio-temporal changes in the pollution are linked to its previous state of the atmosphere. The applicability of these techniques has been tested over Northern Italy to detect ozone pollution episodes in year 2004 using model simulated concentrations. The methods tested in this paper are pixel, block-based, histogram, pertinent pixel and twin-comparison method. While these techniques have some kind of merits and demerits, a modified pertinent pixel comparison algorithm has been proposed to detect pollution episodes. The proposed method has been validated to detect PM10 episodes over Milan metropolitan area during 2 months in 2008 and is able to detect PM10 episodic events as well as non-events. This method provides a single binary index that can be applied by the air quality modellers and decision makers to determine the pollution episode over a given domain.     

Impacts of industrial waste resources on maize (Zea mays L.) growth,yield, nutrients uptake and soil properties

Discharging untreated highly acidic (pH < 4.0), organic and nutrients rich monosodium glutamate wastewater (MW), and highly alkaline (pH > 10.0) paper-mill wastewater (PW) causes environmental pollution. When acidity of MW neutralized (pH 6.5 ± 0.1) with PW and lime (treatments represented as MW + PW and MW + Lime), then MW may be utilized as a potential source of nutrients and organic carbon for sustainable food production. Objectives of this study were to compare the effects of PW and lime neutralized MW and chemical fertilizers on maize (Zea mays L. cv. Snow Jean) plant growth, yield, nutrients uptake, soil organic matter and humic substances. The field experiment was carried out on maize using MW at 6000 L ha^?1. Impacts of the MW application on maize crop and soil properties were evaluated at different stages. At harvest, plant height, and plant N and K uptake were higher in MW treatment. Leaf area index at 60 days after sowing, plant dry matter accumulation at harvest, and kernels ear^?1 and 100-kernel weight were higher in MW + Lime treatment. Kernel N, P, K, Mn, Fe and Zn, and plant Zn uptake were highest in MW + Lime. Plant Fe uptake, and soil organic matter and humic substances were highest in MW + PW. The MW + PW and MW + Lime treatments exhibited comparable results with chemically fertilized treatment. The MW acidity neutralized with lime showed positive impacts on growth, yield and nutrients uptake; nevertheless, when MW pH neutralized with PW has an additional benefit on increase in soil organic matter and humic substances.     

High speed ball nose end milling of hardened AISI A2 tool steel with PCBN and coated carbide tools

High speed machining (HSM) of tool steels in their hardened state is emerging as an attractive approach for the mold and die industry due to its potential for significant cost savings and productivity improvement. An experimental study was conducted to investigate the tool wear mechanism and surface integrity in high speed ball nose end milling of hardened AISI A2 tool steel using coated tungsten carbide and polycrystalline cubic boron nitride (PCBN) tools. It is found that coated carbide tools can only be used at low speed (120 m/min) while high content PCBN tools are suitable for HSM range (470 m/min). PCBN tools produce a damage free workpiece with better surface finish and less work hardening. Despite the higher tool cost, HSM with PCBN tools lead to reduction in both total cost and production time per part.     

Adsorption behavior of benzenesulfonic acid by novel weakly basic anion exchange resins

Two novel weakly basic anion exchange resins(SZ-1 and SZ-2) were prepared via the reaction of macroporous chloromethylated polystyrene-divinylbenzene(Cl-PS-DVB) beads with dicyclohexylamine and piperidine, respectively. The physicochemical structures of the resulting resins were characterized using Fourier Transform Infrared Spectroscopy and pore size distribution analysis. The adsorption behavior of SZ-1 and SZ-2 for benzenesulfonic acid(BA) was evaluated, and the common commercial weakly basic anion exchanger D301 was also employed for comparison purpose. Adsorption isotherms and influence of solution p H, temperature and coexisting competitive inorganic salts(Na2SO4and Na Cl) on adsorption behavior were investigated and the optimum desorption agent was obtained.Adsorption isotherms of BA were found to be well represented by the Langmuir model.Thermodynamic parameters involving ΔH, ΔG and ΔS were also calculated and the results indicate that adsorption is an exothermic and spontaneous process. Enhanced selectivity of BA sorption over sulfate on the two novel resins was observed by comparison with the commercial anion exchanger D301. The fact that the tested resins loaded with BA can be efficiently regenerated by Na Cl solution indicates the reversible sorption process. From a mechanistic viewpoint, this observation clearly suggests that electrostatic interaction is the predominant adsorption mechanism. Furthermore, results of column tests show that SZ-1possesses a better adsorption property than D301, which reinforces the feasibility of SZ-1for potential industrial application.     

Surface ozone scenario and air quality in the north-central part of India

Tropospheric pollutants including surface ozone(O_3), nitrogen dioxide(NO_2), carbon monoxide(CO) and meteorological parameters were measured at a traffic junction(78°2′ E and 27°11′ N) in Agra, India from January 2012 to December 2012. Temporal analysis of pollutants suggests that annual average mixing ratios of tropospheric pollutants were: O_3— 22.97 ± 23.36 ppbV,NO_2— 19.84 ± 16.71 ppb V and CO — 0.91 ± 0.86 ppm V, with seasonal variations of O_3 having maximum mixing ratio during summer season(32.41 ± 19.31 ppbV), whereas lowest was found in post-monsoon season(8.74 ± 3.8 ppbV). O_3 precursors: NO_2 and CO, showed inverse relationship with O_3. Seasonal variation and high O_3 episodes during summer are associated with meteorological parameters such as high solar radiation, atmospheric temperature and transboundary transport. The interdependence of these variables showed a link between the daytime mixing ratios of O_3 with the nighttime level of NO_2. The mixing ratios of CO and NO_2 showed tight correlations, which confirms the influence of vehicular emissions combined with other anthropogenic activities due to office/working hours, shallowing, and widening of boundary layer. FLEXTRA backward trajectories for the O_3 episode days clearly indicate the transport from the NW and W to S/SE and SW direction at Agra in different seasons.     

Soil N balance as affected by soybean maturity class in the Guinea savanna of Nigeria

Legume–cereal rotation may reduce the fertilizer requirement of the cereal crop and we hypothesize that the benefit depends on the maturity class of the soybean. Field trials were therefore conducted in 1995 in four Guinea savanna sites to monitor the effect of soybean (Glycine max (L.) Merrill) cultivation on the N balance of the soil. In trial 1, an early (TGx1485-1D) and a late (TGx1670-1F) soybean were grown to maturity along with a maize (Zea mays L.) reference plot. In trial 2, six varieties of soybean (early: TGx1485-1D, TGx1805-2E and TGx1681-3F; medium: TGx1809-12E and TGx923-2E; late: TGx1670-1F) were grown to maturity along with a reference maize plot. The total nitrogen (N) content, aboveground N₂ fixed, and N remaining in the stover were higher in the medium and the late varieties than in early varieties. Also, the early varieties had higher nitrogen harvest indices (81–84%) than medium and late varieties (74–79%). From the N balance calculation, it was found that medium and late maturing soybean resulted in an addition of 4.2 kg N ha⁻¹ to the soil, whereas the early maturing varieties resulted in depletion of the soil N reserve by 5.6 kg N ha⁻¹ (P<0.05). On average, among the medium and late varieties, late maturing TGx923-2E resulted in an addition of 9.5 kg N ha⁻¹ to the soil. When the stover was not returned to the field, early soybean resulted in more negative N balance than the medium and late soybean (P<0.05). Therefore, planting an early variety of soybean for one season resulted in net depletion of soil N, even when the soybean residues were returned to the soil and N₂ fixed in the roots and N in the fallen leaf litter were included in the N balance calculations. Contrary to this, planting medium and late soybean for one season resulted in an addition of N to the soil. Therefore, medium and late soybean should be used as a preceding crop in legume–cereal rotation, if possible, to minimize or avoid depletion of soil N by early varieties of soybean.     

Fungicidal elements accumulated in Cryptothecia punctulata (Ascomycetes lichen) of an arecanut orchard in South India

Different nutrient elements were analyzed in the lichen Cryptothecia punctulata collected from the arecanut trees which were exposed to several sprays of a fungicide Bordeaux mixture. The study revealed the accumulation of fungicidal elements such as Cu, Ca and S in higher concentration of 575.4, 10,000 and 21,000 microg g(-1), respectively.     

Soil microbial population and enzyme activity related to grazing pressure in alpine meadows of Nanda Devi Biosphere Reserve

The present study aims to analyze the interaction of prevailing biotic pressure on soil environment with emphasis on its physicochemical and microbiological characteristics determining soil fertility status and thus supporting plant and animal biodiversity in Nanda Devi Biosphere Reserve (NDBR) which is located in northern part of Uttaranchal hills between 79 degrees 40'E to 80 degrees 05'E longitude and 30 degrees 17'N to 30 degrees 41'E latitude. The experimental results revealed that the physico-chemical characteristics (viz., moisture, pH, EC, C, N, P, K, CEC) of soil were maximum in moderately grazed meadow and minimum in intensively grazed meadow. Soil microbial analysis measured in terms of total viable count (TVC) exhibited grazing sensitivity trend being maximum population of bacteria > fungi > actinomycetes. The soil microbial population was positively correlated with soil respiration, dehydrogenase activity, acid phosphatase and microbial biomass, which exhibited uneven trend with grazing pressure. Soil from moderately grazed meadow showed highest microbial count and enzyme activities, whilst intensively grazed meadow showed lowest microbial count and enzyme activities. This depicts the beneficial role of prescribed grazing up to limited extent in management of soil fertility, which might have supported luxuriant growth of a variety of grasses.     

Efficacy of different organophosphate and synthetic pyrethroid insecticides to the larvae of malaria vector Anopheles stephensi, Liston

Evaluation of the potency of four organophosphate (OP) (Malathion, Fenthion, Fenitrothion and Temephos) and two synthetic pyrethroid (SP) compounds (cypermethrin and deltamethrin) was carried out against larvae of Anopheles stephensi, the major malaria vector in district Bikaner (Rajasthan). Different concentrations supplied by WHO were used for determining the percent mortalities. LC50 values as calculated by probit analysis were 1.2740, 0.0600, 0.0405, 0.0046, 0.0019 and 0.0016 mg/l respectively for the above six insecticides. Both SP compounds were found more toxic followed by temephos among the OP compounds. Malathion was found the least toxic while fenthion and fenitrothion were in between these two extremes.