Earthworm biodiversity in western arid and semiarid lands of India

Efforts have been made in this study to estimate the current status of earthworm biodiversity in western arid and semiarid lands of India. A total of 513 different locations (rural, urban, and sub-urban localities) covering both arid and semiarid areas were surveyed and 11 earthworm species: Perionyx sansibaricus (Perrier), Amynthas morrisi (Beddard), Metaphire posthuma (Vaillant), Lampito mauritti Kinberg, Dichogaster bolaui (Michaelsen), Octochaetona paliensis (Stephenson), Ramiella bishambari (Stephonson), Ocnerodrilus occidentalis Eisen, Malabaria sp, Allolobophora parva Eisen, and Pontoscolex corethrurus (Müller) belonging to five different families were rerecorded. A few earthworm species, e.g., L. mauritii, M. posthuma, O. occidentalis, and D. bolaui showed their presence in most of the sampling localities, while R. bishambari, Malabaria sp., A. parva, and P. corethrurus were restricted to a particular locality in arid land. Earthworm fauna of this region showed a patchy distribution pattern and the majority of the species were recorded from northern canal-irrigated and central alluvial plain belt (mid to eastern part) of the Thar Desert. Earthworm distribution and species-richness pattern were directly related to the local microclimatic factors and human activities. Thus, results suggested that human activities have been acted as important agency for invasion of earthworm communities in remote areas of western arid land of India.     

Bacterial contamination in drinking water: a case study in rural areas of northern Rajasthan, India

Acid deposition has caused detrimental effects on tree growth near industrial areas of the world. Preliminary work has indicated that concentrations of NO(3-), SO(4)(2-), F( - ) and Al in soil solutions were 2 to 33 times higher in industrial areas compared to non-industrial areas in Korea. This study evaluated soil nutrient bioavailability and nutrient contents of red pine (Pinus thunbergii) needles in forest soils of industrial and non-industrial areas of Korea. Results confirm that forest soils of industrial areas have been acidified mainly by deposition of sulfate, resulting in increases of Al, Fe and Mn and decreases of Ca, Mg and K concentrations in soils and soil solutions. In soils of industrial areas, the molar ratios of Ca/Al and Mg/Al in forest soils were <2, which can lead to lower levels and availability of nutrients for tree growth. The Ca/Al molar ratio of Pinus thunbergii needles on non-industrial sites was 15, while that of industrial areas was 10. Magnesium concentrations in needles of Pinus thunbergii were lower in soils of industrial areas and the high levels of acid cations such as Al and Mn in these soils may have antagonized the uptake of base cations like Mg. Continued acidification can further reduce uptake of base cations by trees. Results show that Mg deficiency and high concentrations of Al and Mn in soil solution can be limiting factors for Pinus thunbergii growth in industrial areas of Korea.     

Production of vermifertilizer from guar gum industrial wastes by using composting earthworm <Emphasis Type="Italic">Perionyx sansibaricus</Emphasis> (Perrier)

Efforts have been made to convert the guar gum industrial waste into a value-added product, by employing a new earthworm species for vermicomposting e.g. Perionyx sansibaricus (Perrier) (Megascolecidae), under laboratory conditions. Industrial lignocellulosic waste was amended with other organic supplements (saw dust and cow dung); and three types of vermibeds were prepared: guar gum industrial waste + cow dung + saw dust in 40: 30: 30 ratio (T₁), guar gum industrial waste + cow dung + saw dust in 60: 20: 20 ratio (T_2,), and guar gum industrial waste + cow dung + saw dust in 75: 15: 10 ratio (T₃). As compared to initial concentrations, vermicomposts exhibited a decrease in organic C content (5.0–11.3%) and C:N ratio (11.1–24.4%) and an increase in total N (18.4–22.8%), available P (39.7–92.4%), and exchangeable K (9.4–19.7%) contents, after 150 days of vermicomposting. A vermicomposting coefficient (VC) was used to compare of vermicomposting with the experimental control (composting). P. sansibaricus exhibited maximum value of mean individual live weight (742.8 ± 21.1 mg), biomass gain (442.94 ± 21.8 mg), growth rate (2.95 ± 0.15 mg day⁻¹), cocoon numbers (96.0 ± 5.1) and reproduction rate (cocoons worm⁻¹ day⁻¹) (0.034 ± 0.001) in T₂ treatment. In T₃ maximum mortality (30.0 ± 4.01 %) in earthworm population was observed. Overall, T₂ vermibed appeared as an ideal substrate to manage guar gum industrial waste effectively. Vermicomposting can be proposed as a low-input basis technology to convert industrial waste into value-added biofertilizer.     

Heavy metal phytoextraction—natural and EDTA-assisted remediation of contaminated calcareous soils by sorghum and oat

The abilities of sorghum (Sorghum bicolor L.) and oat (Avena sativa L.) to take up heavy metals from soils amended with ethylenediaminetetraacetic acid (EDTA) were assessed under greenhouse conditions. Both plants were grown in two soils contaminated with heavy metals (Gujranwala—silty loam and Pacca—clay loam). The soils were treated with 0, 0.625, 1.25, and 2.5 mM EDTA kg^?1 soil applied at both 45 and 60 days after sowing (DAS); the experiment was terminated at 75 DAS. Addition of EDTA significantly increased concentrations of Cd, Cr, and Pb in roots and shoots, and bio-concentration factors and phytoextraction rates were also increased. Post-harvest soil analysis showed that soluble fractions of metals were also increased significantly. The increase in Cd was ≈ 3-fold and Pb was ≈ 15-fold at the highest addition of EDTA in Gujranwala soil; in the Pacca soil, the increase was less. Similarly, other phytoremediation factors, such as metal translocation, bio-concentration factor, and phytoextraction, efficiency were also maximum when soils were treated with 2.5 mM EDTA kg^?1 soil. The study demonstrated that sorghum was better than oat for phytoremediation.     

Growth and fecundity of earthworms: <Emphasis Type="Italic">Perionyx excavatus</Emphasis> and <Emphasis Type="Italic">Perionyx sansibaricus</Emphasis> in cattle waste solids

Epigeic earthworms (Oligochaeta) have been appeared as key organisms to convert organic waste resources into value-added products, i.e., vermicompost and worm biomass. The assessment of reproduction potential of composting earthworm may be beneficial for large-scale earthworm production. Although, the waste minimizing potential of Perionyx excavatus and Perionyx sansibaricus is well proved, but little information is available about their fecundity rate. In this study, the efforts have been made to explore the growth and reproduction biology of P. excavatus and P. sansibaricus, using cattle waste solid as culture substrate, under laboratory conditions. Earthworms were weighed weekly and number of cocoons produced per week assessed. Biomass productions, fecundity, maturation, natality all were significantly different between P. excavatus and P. sansibaricus. The highest mean individual biomass was 767.7 ± 18.4 mg and 612.6 ± 20.6 mg, respectively in P. sansibaricus and P. excavatus. However, the highest cocoon numbers occurred in P. excavatus (492.3 ± 13.6), significantly higher than P. sansibaricus (269.6 ± 17.1). Fecundity was slightly different in both species: 1.38 ± 0.77 cocoons adult worm⁻¹ week⁻¹ (P. excavatus) and 1.58 ± 0.74 cocoons adult worm⁻¹ week⁻¹ (P. sansibaricus). The hatchling success rate (%) was highest in P. excavatus. Overall natality (juveniles adult⁻¹ week⁻¹) was highest in P. sansibaricus (1.52) than P. excavatus (1.26), which suggests that P. sansibaricus may be a better candidate for rapid propagation of earthworms in cattle waste solid.     

Assessment of physicochemical parameters of wastewater samples

Water samples from selected locations of Nullah Lai and Koh-e-Noor textile mill in the metropolitan city of Rawalpindi and Islamabad, Pakistan, were collected. Physicochemical parameters and heavy metals were determined using standard analytical procedures in comparison with sites, locations and subsequent interval of 3 months. The results of the physicochemical analysis at different locations of Nullah Lai and Koh-e-Noor textile mill with an interval of 3 months were obtained in the following range: pH (7.16–8.29), temperature (17.8–28.8 °C), conductivity (1,005–3,347 μS/m), TDS (754.3–2,519.5 mg/L), turbidity (272.8–487.05 NTU), total hardness (300–452 mg/L), nitrates (10.11–22.95 ppm), calcium (74.31–139.2 ppm), chloride (127.72–396.16 ppm), sulphate (15.97–87.38 ppm), NaCl (210.5–631.1 ppm), Ni (0.30–0.72 ppm), Cd (0.005–0.03 ppm), Cr (0.2–7.4 ppm), Pb (0.12–0.73 ppm), Zn (0.03–0.08 ppm) and Cu (0.01–0.06 ppm). The highest value of physicochemical parameters (compared with Nullah Lai) was obtained in locations of Koh-e-Noor textile mill. The results obtained exceeded the maximum allowable limit set by the World Health Organization for drinking purpose but can be used for irrigation purposes after suitable treatment and purification.     

Phytotoxicity of composted herbal pharmaceutical industry wastes

This work demonstrates the phytotoxicity screening of composted herbal pharmaceutical industry waste (HPIW) using seed bioassay method. The composted industrial waste should be tested at lab scale prior to recommendation for land application. HPIW was mixed with soil to produce four treatments: T(1) (1:1), T(2) (1:2), T(3) (1:3), and T(4) (1:0) for toxicity screening using Pisum sativum seeds. After 72?h relative seed germination (RSG), relative root growth (RRG) and germination index (GI) were recorded. Seedlings were observed for further plant growth and tissue biochemistry (chlorophyll, soluble sugar, starch, carotenoid, and protein) estimation. RSG, RRG, and GI values were better in T(1) and T(2) than others. GI was in the ranges of 36.62?% (T(4)) to 170.38?% (T(2)). The seedling growth and biochemical parameters were better in seedling obtained from potting media containing low proportion of HPIW (i.e., T(1) and T(2)). Results clearly suggested that composted HPIW may be utilized effectively for crop production after dilution under sustainable farming system program.     

Fluoride contamination in drinking water in rural habitations of Northern Rajasthan, India

This study was carried out to assess the fluoride concentration in groundwater in some villages of northern Rajasthan, India, where groundwater is the main source of drinking water. Water samples collected form deep aquifer based hand-pumps were analysed for fluoride content. Fluoride in presently studied sites was recorded in the ranges of 4.78 and 1.01 mg/l. The average fluoride concentration for this region was recorded 2.82 mg/l. As per the desirable and maximum permissible limit for fluoride in drinking water, determined by WHO or by Bureau of Indian Standards, the groundwater of about 95 of the studied sites is unfit for drinking purposes. Due to the higher fluoride level in drinking water several cases of dental and skeletal fluorosis have appeared at alarming rate in this region. The middle and eastern parts of the Hanumangarh, a northern most district of the state, can be classified as higher risk area for fluorosis; due to relatively high concentrations of fluoride (3-4 mg/l) in groundwater of this region. After evaluating the data of this study it is concluded that there is an instant need to take ameliorative steps in this region to prevent the population from fluorosis.     

Earthworm density,casting activities and its impact on canopy soil nutrient profile under different aboveground vegetations

Efforts were made to assess the earthworm’s density and their casting activity under different surface plant stands (Citrus reticulata, Rosa indica, Citrus + Rosa, Tabernaemontana divaricata, Dalbergia sissoo, and Cynodon dactylon) at few natural and planted sites of a semiarid part of Rajasthan, India. The role of earthworm community in nutrient dynamics of different layers of canopy soils was also measured during this study. Results suggested a direct impact of aboveground vegetation cover on soil microclimatic conditions and earthworm density. The maximum earthworm population density and casts production was under mixed plantation, i.e., Citrus + Rosa (119.2 ind. m⁻² and 2,127.27 gm m², respectively), while T. divaricata supported the minimum earthworm density and casting activities. The population density and total casts production was in the order: C. reticulata + R. indica > R. indica > D. sissoo > C. dactylon > C. reticulata > T. divaricata. Earthworm casts and canopy soils (0–10 and 10–20 cm depth) under different plant stand were analyzed for organic C, total N, available P, and exchangeable cations (K⁺, Ca²⁺ and Mg²⁺). Earthworm casts collected under Citrus + Rosa showed the maximum level of organic C, total N, available P, and exchangeable cations (K⁺ and Mg²⁺). It is concluded that resource input by standing plant community directly affects the canopy soil quality and, thereby nutrient level in earthworm casts. This study suggested that aboveground vegetation pattern plays an important role to improve the nutrient level of canopy soils and belowground earthworm activities.