Review on Utilization of Plants for the Phytoremidiation Purpose on Heavy Metal Contaminated Soil

Heavy metal pollution in the soil has been the main environmental problems in recent years all over the world. Heavy metals that are commonly contaminating soil include lead, chromium, arsenic, zinc, cadmium, copper, mercury and nickel. The main sources of these metals are dust produced by energy, transport, metallurgy, production of construction materials; sanitary sewage, chemical wastewater, industrial mining wastewater and urban mining mixed sewage; mining and industrial solid waste contamination, Fertilizers and pesticides are important agricultural inputs for agricultural production and there is a growing public concern over the potential accumulation of heavy metals in soil owing to rapid industrial development and also the heavy metals pollution is one of the problems that arise due to the increased uses of fertilizers and other chemicals to meet the higher demands of food production for human consumption. Heavy metals exhibit toxic effects towards soil biota by affecting key microbial processes and decrease the number and activity of soil microorganisms. Even low concentration of heavy metals may inhibit the physiological metabolism of plant. Plants growing on these soils show a reduction in growth, performance, and yield. Uptake of heavy metals by plants and subsequent accumulation along the food chain is a potential threat to animal and poses serious health risks to humans. To overcome the problem phytoremediation using of plants to reduce the concentrations or toxic effects of heavy metal contaminants in the environments and relatively recent technology which perceived as cost-effective, efficient remedy of soils by improving phisico-chemical of the soil with cheap and practically acceptable techniques. Keywords: Contaminants, Heavy metal, Phytoremediation, Soil, Toxic DOI: 10.7176/JNSR/9-6-0

The Role of Biochar Amendments on Soil Properties, Waste Water Treatment and Carbon Sequestration A: Review

Biochar is the by-product of biomass pyrolysis in an oxygen depleted atmosphere. It contains porous carbonaceous structure and an array of functional groups. Biochar’s highly porous structure can contain amounts of extractable humic-like and fluvic-like substances. Moreover, its molecular structure shows a high degree of chemical and microbial stability. The physical and chemical properties of biochar are highly dependent on pyrolysis temperature and process parameters, such as residence time and furnace temperature, as well as on the feedstock type. Recent increases in atmospheric greenhouse gas levels require that novel approaches are undertaken to mitigate impacts of climate change, such as management practices conducive to improved soil carbon sequestration. Water usage has been rising immensely with growing population and industrial activities in both developed and developing countries. This resulted in deterioration of water sources as various contaminants such as dyes toxic heavy metals, organic compounds like detergents, phenols, dyes, pesticides in addition to the other persistent organic pollutants are increasingly being dumped into the water bodies. Recently, char derived from biological materials under oxygen free condition, popularly known as “biochar” has been recently been introduced as an effective sorbent for various toxins. Biochar application as a soil amendment is motivated by its capacity to enhance crop yields and alter the soil physical, chemical and biological properties, such as soil water holding capacity, pH, cation exchange capacity, nutrient retention, and organic carbon. Biochar has been recently recognized as multifunctional material related to carbon sequestration, contaminant immobilization, greenhouse gas reduction, soil fertilization, and water filtration. Accordingly, biochar is presented as a promising soil amendment of high economic and environmental value. Keywords: Amendment, Carbon, Pollutant, Pyrolysis and Surface area DOI: 10.7176/JRDM/91-01 Publication date:September 30th 202

Effects of Lime and Phosphorus Rates on Growth of Hybrid Arabica Coffee Seedlings at Jimma, Southwest Ethiopia

Coffee growing soil of southwestern region parts of Ethiopia are classified as Nitisols with having a low pH and highly deficient in phosphorus. A nursery experiment was conducted at Jimma Agricultural Research Center, southwestern Ethiopia to evaluate the effects of lime and phosphorus rates on coffee seedling growth under nursery conditions. The experiment was laid out in a randomized complete block design with 3 replications. The treatments were arranged in factorial combinations of five levels of lime (0, 5, 10, 15 and 20 g) and four levels of phosphorus (0, 400, 600 and 800 mg) 2.5 kg-1top soil. The statical data was analyzed through SAS software and treatment means were compared at 5% probability using Duncan Multiple Range Test. The results revealed that the interactions of lime and P rates significantly increased the growth of both non-destructive parameters (plant height, girth, number of nods, interned length, leaf number and leaf area) and Root growth parameters (taproot length, lateral root length, lateral root number, root volume, leaf stem and root fresh weight, of coffee seedlings. The maximum shoot and root extensions were obtained from the interaction of 10 g lime and 800 mg P rates 2.5 kg-1top soil. On the other hand, applications of P significantly (P≤ 0.01) affected soil and plant growth parameters. As P rate increased availability P boosted and plant growth were enhanced. Similarly, an application of lime significantly affected (P≤ 0.01) plant growth and enhance nutrient availability up to 10 g, though further applications adversely affect seedling growth and nutrient availability. Hence, combined application of 10 g lime and 800 mg P rate 2.5 kg-1top enhances the optimum growth of coffee seedlings under nursery conditions. Keywords: Coffee nursery, Coffee seedlings, Exchangeable acidity, Lime rates DOI: 10.7176/JBAH/9-15-04 Publication date: August 31st 201

Wind Erosion Process, Factor, Effects on Agricultural Soil and Mitigation Mechanism: A Review

Wind erosion is a significant environmental challenge that has profound effects on soil quality and agricultural productivity. Wind erosion degrades soil quality by removing nutrient-rich topsoil, leading to a decrease in soil fertility. This degradation can significantly impact agricultural productivity, leading to lower crop yields and, consequently, reduced income for farmers. Wind erosion can lead to the loss of organic matter and beneficial microorganisms, further exacerbating soil degradation and productivity loss. Mitigation methods for wind erosion are therefore of paramount importance. These include practices such as cover cropping, windbreaks, and conservation tillage. These methods not only protect the soil but also contribute to sustainable farming Keywords: Erosion, Nutrient, Wind, Mitigation and Soil DOI: 10.7176/JRDM/91-03 Publication date:September 30th 202

The Effects of Vetiver Grass (Vetiver Zizanodes L.) on Soil Fertility Enhancement, Soil Water Conservation, Carbon Sequestration and Essential oil Productions A: Review

Vetiver (Vetiver zizanioides L.) is a perennial grass is one such species that could be grown all across the globe from tropical to Mediterranean climate. The grass fits well in ecosystem service which contributing to regional and global economies for its multifarious environmental application and offers sustain able opportunities for carbon sequestration. Vetiver is the high tolerance of a wide range of extreme soil conditions, such as high and low pH, high aluminum, high salinity, and high sodicity. Vetiver grass is a very simple, practical, inexpensive, low maintenance and very effective means of soil and water conservation, sediment control, land stabilization and rehabilitation. It is also environmentally friendly and when planted in single rows it will form a hedge which is very effective in slowing and spreading runoff water, thereby reducing soil erosion, conserving soil moisture. In addition, the extremely deep and massively thick root system of vetiver grass binds the soil and at the same time makes it very difficult for it to be dislodged under high water velocity. the use of vetiver grass improved soil quality through improving CEC, soil moisture content, soil organic matter, total nitrogen, available phosphorus and available potassium contents. Carbon sequestration implies capture and secure storage of Carbon that would otherwise be emitted to or remain in the atmosphere. Carbon sequestration is an efficient strategy to mitigate climate change. Vetiver holds prominence as one of the world’s best carbon-sequestering plants. Four mature vetiver plants would sequester the same amount of atmospheric carbon as one fast-growing poplar tree, the best of all trees for carbon sequestration. Vetiver oil and its fractions are heavily used for blending in oriental types of perfumes, cosmetics and aromatherapy. It also has antifungal, antibacterial, anticancer, anti inflammatory and antioxidant activities, opens the way to application in the pharmaceutical industry. Keywords: Carbon sequestration, organic matter, rehabilitation, soil erosion, vetiver DOI: 10.7176/JNSR/13-5-04 Publication date:March 31st 202

The Impacts of Salt Affected Soil on Soil and Plant Growth and Management Options with Organic and Inorganic Amendments A: Review

Globally, 833 million ha of soils are salt-affected. Approximately 20% of the world’s cultivated lands and 33% of irrigated lands are salt affected. Soil salinization is spreading at the rate of 1–2 million ha year- 1 globally affecting a significant portion of crop production and making land unsuitable for cultivation. Salinity problems occur under all climatic conditions and can result from both natural and human-induced actions. Generally speaking, saline soils occur in arid and semi-arid regions where rainfall is insufficient to meet the water requirements of the crops, and leach mineral salts out of the root-zone. Salt-affected soils are characterized by the presence of sodium, calcium, magnesium, chlorides, sulfates, carbonates, and bicarbonates at elevated concentrations. However, based on sodium ion and salt concentration, salt-affected soils are categorized into saline, sodic, and saline–sodic soil. Soil salinity is a major problem which can reduce soil microbial community, enzymatic activity, respiration rate of soil, and the bacteria growth of the soils. Salinity negatively influences almost all plant processes including plant growth and plant structure, through biochemical and physical disturbances, ionic imbalance and toxicity, nutrient deficiencies, and osmotic and oxidative stresses. One of the primary effects of salt-affected soil on grain yield is reduced water availability. High salt concentrations in the soil create an osmotic imbalance, making it difficult for plants to absorb water. Soil amendments that have been studied for the reclamation of salt-affected and acid sulfate soils can be divided into two main categories, namely, inorganic and organic amendments. Gypsum, iron sulfate chloride, and sulfuric acid are the widely applied inorganic soil amendment agents having proven reclamation potential for salt-affected soils. Whereas, organic amendments like organic matter, biochar, compost, vermicompost and bio-fertilizers application is anther options for reclamation of salt affected soils. Keywords: Amendments, gypsum, salt affected, sodium, soil DOI: 10.7176/JNSR/14-10-02 Publication date:July 31st 202