Population Dynamic of the Legume-Rhizobium System

The use of too much fertilizers, and in particular, of fertilizers with high concentrations of nitrogen, has been linked to reduced biodiversity (Xiankai et al. 2010). It becomes necessary to consider the detrimental effects of high concentrations of fertilizer in the reduced spaces. Fertilizers are salts, and therefore high concentrations of fertilizers can deplete the plant from water.

Farming with an excess of nitrogen levels can cause much harm on the ecosystems and makes it difficult for the nature to handle to excess levels. Does high nitrogen levels also affect the boundary of land use? Does farming used in ice free lands also have an issue of high nitrogen levels?

Vast numbers and kinds of organisms, mainly microorganisms, inhabit soil and depend on it for shelter, food, and water. Plants anchor themselves in soil, and from it they receive essential minerals and water. Terrestrial plants could not survive without soil, and because we depend on plants for our food, humans could not exist without soil either (Wiley, 2013).

The pH of soil is important for the absorption of nutrients into the plant. Of the 17 needed plant nutrients 14 of them are acquired through the soil. Acidity is needed to break down and dissolve these nutrients. The nutrients are able to dissolve into the soil faster when the acid is acting as a solute. Another way the pH affects the soil is by influencing microorganisms. The bacteria is crucial in the growth and development of the plant, the bacteria’s role is to break down and decompose organic matter in the soil. If the pH of the soil is too high the acid will slow down and eventually stop the microorganisms. Most plants ideal pH is between 6-7, slightly acidic. Many plants are outliers and thrive in pH such as carrots and corn, which can withstand pH as low as 5.5. If the pH of the soil is too high for the desired crop farmers can add material such as limestone, and wood ashes to raise the pH to the desired level. The pH of the soil can also be changed naturally through the leaching of calcium, magnesium and sodium by rainwater. Carbon dioxide from rotting organic matter can also increase the pH of the soil. Acids can also be created organically in the form of sulfuric and nitric

Bioremediators need to be able to grow in order to remediate the soil of pollutants. The purpose of this research is to determine whether the presence of Stropharia rugoso-annulata in the soil will support and accelerate the growth of ryegrass in a mutualistic symbiotic relationship. If the growth of the ryegrass is accelerated and supported, the combination of the two bioremediators could potentially accelerate the degradation of PAHs in the soil. Techniques such as soil washing, soil flushing, vitrification, etc., exist to remediate contaminated soil. Although, these techniques are effective, they also disturb the natural environment to some degree. Bioremediation is often accomplished in situ resulting in minimal environmental disturbance. This study is being performed because healthy soil is a limited resource that needs to be preserved and replenished. The state of soil can impact the health of humans, animals, and ecosystems, therefore, it’s important to be able to monitor and control the pollutants in

Prokaryotes are ubiquitous, successfully adapting to diverse environments as well as developing symbiotic relationships with host organisms (Lengeler, Drews, & Schlegel, 1999). Prokaryotes may have both autotrophic and heterotrophic characteristics. A cyanobacteria is photosynthetic, commonly called blue-green algae, and may produce toxins (Crayton, 1993). Bacteria are most commonly associated in the general

Many species of plants host microorganisms living inside the plant forming a mutually beneficial endosymbiosis. Bacteria or fungi that reside within plant tissue (roots, stems, and/or leaves) are referred to as endophytes. These endophyte communities may help to improve a plant’s fitness by promoting growth, protecting against disease, or facilitating nutrient acquisition. More specifically, endophytes within the plant community can help plants respond to stress that develops from biotic or abiotic influences like pests, heat, drought, saline, and soil conditions (Russell et al., 2003) Endophytes can help plants become better able to tolerate stress by allocating resources from one place to another (Rodriguez et al., 2009). Therefore,

9. In the research done on the microbial community in the Rhizosphere using two methods, which are the Cultivation-dependent method and Cultivation-independent method. The research and studies done had good results, moreover, the physiological profiling was done in 5 days by the use of several carbon sources. The maximal growth was observed for the 30 degrees celsius- incubated plate by day 3, whereas comparable values were recorded for the room to the temperature-incubated plate by day 5.

Glomalin is a type of protein that works as a natural glue preventing soil from washing away. The producer of this protein is a type of fungi, which is torn by tillage during plowing. However, research shows that farming without tillage (silvopastoral systems for example) has the opposite effect because it leads to an increase of fungi and glomalin. The fungi carries minerals to the plants in exchange for carbon, which the plant takes from the atmosphere; therefore grazing areas such as rangelands and pasture lands can play an important part in restoring lost carbon soil (Niman, 28-30). Grass is also capable of producing soil carbon. According to the UK Soil Association, “Grass has high root densities, fine root hairs, and high mycorrhizal fungal levels, all of which increase soil aggregation. Animal manures and compost also promote soil carbon, again reinforcing how including animals in farming benefit carbon sequestration” (qtd. in Niman, 31). Niman concludes that while converting grassland to croplands does cause carbon losses, converting cropland into grass results in carbon gains (Niman, 32). In a study by the University of Maryland, field tests on 6 different continents consistently showed that the areas with grazing animals had a greater plant diversity than those without animals. These scientists argue that “the absence of animals rather

Bacterial symbionts are predominant among organisms that shape the biological world (Hurst 1993, Wernegreen 2004). Some of the bacterial symbionts that have an inordinate influence on the health and evolution of their hosts are those bacteria that live within their symbiotic hosts, so-called endosymbionts. Bacterial endosymbionts are the focus of current research programs by the National Institutes of Health (Human Microbiome Project, http://www.hmpdacc.org/) and the National Science Foundation (The Symbiosis, Defense, and Self-recognition Program).

This theory developed by Joseph Francis states that microbes and viruses were created as a link to macro-organisms to provide a substrate upon which all macro-organisms can survive and thrive in ecosystems (Francis). The evidence of this can be seen in symbiotic relationships between microbes and macro-organisms that provide the macro-organisms the ability to live and thrive. An example of this would be the intestinal microbes in humans that provide digestive enzymes, vitamins, and other nutrients that are vital to the health of the human (Francis). Another example would be nitrogen fixing bacteria that promote plant growth. This would include Burkholderia phymatum and Cupriavidus taiwanensis with Mimosa plants. (Geoffrey et al., 2006). Also, Francis mentions the Rhizobium bacterium which also fixes nitrogen for plant use (Francis). Without these microbes, the macro-organisms would not be able to function to their best capability and could possibly cause the breakdown of all life

According to ….the earth’s atmosphere contains 78% nitrogen, 21% oxygen, and 1% CO2 and other gases. Nitrogen makes up almost four fifths of the air we breathe. we already have 25% more nitrogen percentage than is said in this article . we just inhale and exhale the nitrogen back out again, unchanged. It is essential for the growth of most living things. She may think that nitrogen is harmful but as identified on …. It is a fundamental for life .

Our predictions came out to be false. The controlled groups had a higher average in shoot length and wet mass, which indicates that the plant and fungus have a parasitic relationship towards each other. Introduction:

Introduction Nitrogen and phosphorus are parts of two biogeochemical cycles that coexist in nature. Although they occur simultaneously, they have a plethora of ways in which they differ. There is however one thing they have in common – the fact that their supply is essential to all forms of life. Nitrogen cycle encompasses large flows of nitrogen between the atmosphere, lithosphere, hydrosphere, and biosphere. The vast amount of nitrogen can be found in the atmosphere, and it accounts for 80% of the atmospheric gases (Fields 2004).

They then gradually spread and form ring of necrotizing tissue (Sedlakova et al 2011). At first the plant will look healthy before the lesions are visible on the outside. This is also a challenge for the farmers because they will not know if their produce is unhealthy until it is visible. By the time they can cut of the plant the disease would have spread to the neighboring plants as well. P. infestans are produced through sexual and asexual mating. The two mating types are known as A1 and A2 ( Nowicki et al 2012). When mycelia of both types interact they produce oospores sexually. Mycelia is the branched filament of fungi (Encyclopaedia Britannica 2017). Oospores are spores that have a thick coating that allows them to survive harsh environmental conditions for a long period (Nowicki et al 2012). When both these types mate they produce a worse isolate compared to only if A1 mating occurs. The production of these more harmful isolates was detected by researchers in United States which has made controlling this pathogen more difficult (Fall et al 2015). Sporangia of P. infectans also produce zoospores through asexual mating. Sexual and asexual mating is influenced by the environment. Asexual is mating is encouraged when the weather is a warmer and oospores are produced in cooler weather hence for the thick coating of oospores.