Hazard quotient, microbial diversity, and plant composition of spent crude oil-polluted soil

Abstract Background The present work assesses the concentration of some heavy metal, plant species composition, and microbial diversity of spent crude oil-polluted soil from electric generator plant house, auto mechanic workshop, bakery, and auto spare part shops in four local governments areas (Egor, Ikpoba-Okha, Oredo, and Ovia North) in Edo State, Southern Nigeria. Results Hazard quotient (HQ) of heavy metals varied in all the spent crude oil-polluted soil evaluated in the study. The HQ of heavy metals from auto mechanic workshop had the highest values for Cr (2.19), Mn (0.0965), Zn (4.1108), Fe (9.32015), and Cd (0.0155). The most frequent bacterial and fungal species found in all 16 sites were Bacillus subtilis (93.75%) and Aspergillus niger (100.0%) respectively. Auto spare part shops in Oredo had a bacterial count of 1.0 × 105 CFU/g while the bacteria count around power generator plants in Egor had a bacteria count of 1.71 × 105 CFU/g. Some of the plant species identified around all the sites include Acanthospermum hispidum, Alternanthera repens, Axonopus compressus, Cyperus esculentus, Eleusine indica, Paspalum scrobiculatum, and Tridax procumbens. Conclusion Spent crude oil pollution of the soil led to high amounts of heavy metal in the soil. However, the presence of higher plants and variable diversity and richness of microorganisms found in the soil are likely contributing to the remediation of the polluted soil

Phytoremediation Potential of Four Heavy Metals in Soil by Chromolaena odorata (L.) King & Robinson at the Phytotoxicity Screening Benchmarks

The remediative capacity of Chromolaena odorata with respect to heavy metal induced growth-stress was investigated. This was with a view to providing information on the adaptive mechanisms adopted by the test plant during the phytoremediation of selected heavy metals such as copper, manganese, zinc and cadmium. Stems of C. odorata were planted in soils polluted with  Mn, Zn, Cd, and Cu at the ecological screening benchmark (ESB) of 50 mg/kg (Mn and Zn), 4 mg/kg (Cd) and 100 mg/kg (Cu) of metal per kilogram of soil, in varying concentrations of 0 ESB (control), 1 ESB, 3 ESB and 5 ESB. After the exposure of C. odorata to heavy metals for 3 months, results showed that the plant accumulated more Zn in the roots than in both leaves and stems put together in the present study. This, points to Zn exclusion. Accumulation of metal occurred generally in the intermediate and younger leaves; the older leaves were senesced. The totality of heavy metals (HM) accumulated by plant at each time of observation was always below phytotoxicity benchmark. This suggests HM avoidance, or perhaps one of several reasons for plant survival. At all times, it was observed that the totality of HM accumulated in all the plant parts put together was always below ESB value at each time.Keywords: Chromolaena odorata, heavy metal, remediation, phytotoxicity, phytoscreenin

Germination response of coconut (Cocos nucifera L.) zygotic embryo

The study investigated the effects of liquid and solid media in the propagation of coconut (Cocos nucifera) zygotic embryos at initiation stage. Eeuwen’s medium supplemented with growth hormones naphthalene acetic acid ( NAA) and indole butyric acid (IBA) at different concentrations (0.5, 1.0, 1.5, 2.0 and 2.5mg/l) were used for this experiment in both liquid and solid states. Results showed that liquid state medium was better compared to solid state, with a successful shoot emergence of 46.7% of inoculants, compared to 13.3% in the solid state. Within 2 – 4 weeks, 77.8% of germinated zygotic embryo developed shoots in the liquid medium compared to 50% rate in the solid medium. Comparing zygotic embryo development in NAA and IBA, results showed that root yields were better in NAA, with inoculants in 1.5 mg/l NAA showing profuse rooting compared to 0.5 – 2.0 mg/l IBA with no root development. Keywords: Coconut, Eeuwen’s medium, hormones, root yield, zygotic embry

Single-tree influence of Tectona grandis Linn. f. on plant distribution and soil characteristics in a planted forest

Abstract Background Little is known about the single-tree influence of Tectona grandis Linn. f. on plant distribution and soil characteristics in Benin City, Nigeria. We investigated the possible single-tree effect of T. grandis on understory plants in an 8-year-old teak plantation at the Moist Forest Research Station. An area of 36.57 m by 60.96 m was marked out and divided into 15 equal-sized subplots containing 10 trees per subplot. Marked distances from the base of a randomly selected tree per subplot were made (0–0.5 m, 0.5–1.0 m and 1.0–1.5 m). Results Single-tree influence of T. grandis was observed in the soil total organic carbon, total nitrogen and soluble phosphorus, where concentrations were higher with 1.5-m radius from the tree than beyond. Moreover, the pH of the topsoil within 1.5 m from the base of the tree was lower (pH 4.4) than beyond 1.5 m from the base of the tree (pH 5.4). Species-specific single-tree effect was also observed on the understory plant distribution likely due to diverse ecophysiological interactions. Within 1.5 m from the tree, plant species abundance, especially of Sida garckeana, Reisantia indica, Momordica charantia and Tridax procumbens were negatively affected. However, the distribution of Eleusine indica around the tree was not negatively influenced. Plant abundance was generally suppressed in Cynodon dactylon, Axonopus compressus, Andropogon gayanus, Commelina diffusa and Euphorbia hirta. Generally, there were more plant species beyond the canopy fringes than within the canopy, indicating inhibitory single-tree effects. Conclusion Not all plant species in close proximity to T. grandis are affected. This is important considering that plant-plant associations affect the quality of forest soils. Generally, more plant species were recorded outside the 1.5-m demarcation than within, an increase in soil organic matter may further enhance such plant species abundance. The impact of T. grandis in forest soil quality is possibly a factor of the outcome of its association with neighbouring plant species. Diverse mechanisms at play may be responsible for the observed effects on soil chemistry. However, a reduction in the soil organic matter and variations in other environmental factors also contributed to observed single-tree effect

Genetic Assessment of Three Colour Variants of African Yam Bean[Sphenostylis Stenocarpa] Commonly Grown in the Midwestern Region of Nigeria

Abstract Three varieties of African yam bean (Sphenostylis stenocarpa) were collected from six different locations in Edo State, Nigeria (Ekpoma, Benin City, Auchi, Igueben, Igbanke and Sabongida Ora). These seeds were then characterized based on seed colour into black, brown, and light grey. The seeds were screened in the field for agronomic and yield associated characters as well as chemical composition of the seeds. Considerable variations were observed in both agronomic and yield associated characters like shoot height, leaf area, grain yield and total ash content of the seeds. The black colour variant was significantly (p<0.05) highest in grain yield per hectare (1542.28kg/ha) compared to both brown variant (1304.23kg/ha) and the light grey type (1259.97kg/ha)

Influence of Traditional Taboo Practices on Natural Resource Conservation in Uli, Ihiala Local Government Area of Anambra State Nigeria; Sustainable Community Development.

Environmental sustainability is the conservation and maintenance of the ecological integrity of a given area. The present study investigated the effective use of traditional laws and taboo practices in the preservation of the natural resources of Uli, a town in Ihiala Local Government Area of Anambra State Nigeria. The study examined strategies employed in environmental sustainability in this area at the period leading upto Nigeria’s independence in 1960, impact of the civil war (1967-1970) and its aftermath till date. The instruments used for the data collection included literature review, field survey using the questionnaire, one on one oral interviews and photographic documentations of the selected areas. The results showed that fifteen (15) species of plants were preserved using traditional laws. These include: Newbouldia laevis, Treculia africana, Elaeis guineensis, Anthocleista vogelii, Milicia excelsa, Irvingia gabonensis, Cola nitida, Khaya grandifoliola, Ceiba pentandra, Chrysophyllum albidium, Dialium guineense, Canarium schweinfurthii, Baphia nitida, Brachystegia eurycoma, Pterygota spp. Of the three forests in Uli, the “Attammiri” forest is the only one that has remained intact over the years, using traditional laws. The study statistically inferred that the Nigerian Civil war had no significant adverse effect on the use of traditional laws in the protection of the forests in Uli (PBrachystegia eurycoma and Milicia excelsa species. For development to be sustainable, respect for culture and traditional laws at the village-community level should be encouraged and stiffer sanctions accompany offenders

Shelf Life, Fruit Quality and Safety of Banana (Musa Species) Ripened through Traditional Ripening Techniques in Nigeria

Many fruit vendors in Nigeria adopt unhealthy practices to induce fruit ripening and increase the availability of ripe fruits in the markets. We investigated the safety of traditional induced ripen..

Effects of Soil Amendments on the Intrinsic Qualities and Development of Soil Seed Bank of a Monitored Naturally Attenuated Petroleum Hydrocarbon-Polluted Soil

A record of the soil seed bank in oil polluted areas is necessary to assess their capacity for tolerance and phytoremediation potentials of such polluted sites. The present study investigated the effect of soil amendments on the development of soil seed bank of a waste engine oil polluted soil. Top soil (0- 10cm) was collected from an area of known soil seed bank and physiochemical parameters. The soil was then contaminated at 5 % w/w oil-in-soil and immediately amended with poultry manure, sawdust and dried leaves of Vernonia amygdalina and a combination of any of the amendments. Results showed that at 3 months after pollution (MAP), there was general reduction in heavy metal composition and polyaromatic hydrocarbon (PAH) contents of the soil. This content significantly reduced to 46.85 mg/kg 3 months after pollution using treatment SD. The heavy metal content of Fe was 3250.1 mg/kg. This reduced to 934.5 mg/kg using treatment SD with similar reductions in Mn, Zn, Cu, Cr, Cd, Pb, Ni and V contents. Euphorbia spp were the most prevalent weeds. Soil amendment of waste engine oil polluted soil showed the influence on the enhancement of the soil seed bank. Weed diversity was also affected with significant improvement recorded in the polluted soil which probably resulted from enhanced biodegradation activities. Indigenous plant species (particularly Euphorbia spp. and Cyperus sp.) should be used together with soil amendments in phytoremediation following results from present study. Keywords: attenuation, bioremediation, heavy metals, petroleum hydrocarbons, soil amendment, soil seed bank

Seed Priming with Phytohormones

Improving growth and yield properties of plats has been the major aim of most researchers in plat science field. Several strategies have been suggested in order to sustainably improve crop yield. Among these strategies is biopriming, has gained the highest attention being the most effective strategy. Biopriming is a technique involving pre-soaking of plant seed into a solution in order for the metabolic processes to be enhanced before to germination, thereby improving the percentage and rate of germination and increase seedling growth and crop yield under normal and different environmental stresses. The most important aspects of phytohormones is that they are very essential in the regulation of plant development and growth and also functions as an essential chemical messengers, allowing plants to thrive even during exposure to various stresses. Priming plant seeds with phytohormones has led to improved growth and yield of plants in developing countries. Furthermore, it has emerged as an important tool for mitigating the effects of environmental stress. However, this innovation has received less attention from local farmers and merger work has been reported. Therefore, this review discusses the mechanism and potential role of priming with phytohormones to enhance crop productivity and improve plant tolerance to biotic and abiotic stressors

Growth and yield performances of rice ( Oryza sativa var. nerica) after exposure to biosynthesized nanoparticles

Abstract Background Rice (Oryza sativa L.) is a common staple food in Nigeria. However, cultivation is impaired by heavy metal contamination, particularly iron (Fe). This study aimed to investigate the impacts of biosynthesized nanoparticles (NPs) in enhancing the growth and yield components of rice sown in ferruginous soil. Viable seeds of O. sativa var. nerica were sown in ferruginous and non-ferruginous soils. After four weeks, the plants were exposed to foliar sprays of biosynthesized NPs from silver nitrate, using extracts of leaves of Carica papaya, Vernonia amygdalina, Moringa oleifera, and Azadirachta indica; and the flowers of Hibiscus sabderiffa, following standard procedure. The originally prepared stock solution was diluted to give 5, 15, and 30% concentrations of each synthesized NP. Results Results showed that soil ferrugenicity impeded the growth and yield of rice. Azadirachta-synthesized NPs was better enhanced in the ferruginous soils, which might be due to Fe interaction and activities. Moreover, there was increased antioxidant activity in the ferruginous rice compared to the non-ferruginous rice, thus it is evidence that ferrugenicity is a major source of physiological stress for the rice plant. Conclusion The study provided evidence that Ag-NPs can enhance plant yield by huge proportions in ferruginous soil, a condition (ferrugenicity) that was hitherto inimical to yield disposition of rice