The paper presents a review of some foreign publications that discusses the advantages of microbiological fertilizers.
Key words: chemical, microbiological fertilizers; pesticides.
It is generally known, fertilizers and pesticides of various types have been used to increase crops and reduce damage from insects and agricultural diseases for many years. As farmers began to use chemically manufactured fertilizers and pesticides, these compounds gradually became part of normal cultivation practices. Though chemical fertilizers increase food production for nations all over the world, the negative effects to the environment have become inarguable [1].
Nevertheless, the tendency to find alternatives to chemical fertilizers and pesticides intensified around the world as well as disadvantages of the use of chemicals in agriculture have been seen in recent years. Organic farming may be the only alternative to get rid of chemical fertilizers and synthetic pesticides. It should be noted, the method of farming in the world shows the benefits of organic farming methods usage. Organic farming helps to increase food production without pesticides and fertilizers. Organic production is a system of farming that restores, maintains and improves the ecological balance.
Biological fertilizers have been identified as alternative to chemical fertilizers to increase soil fertility and crop production in sustainable farming. There are abundant microorganisms thriving in soil, especially in the rhizosphere of plants. Application of beneficial microbes in agricultural practices started about 50 years ago and now there is increasing evidence that these can also enhance plant resistance to adverse environmental stresses, e.g. water and nutrient deficiency and heavy metal contamination [2].
This paper presents a review of some foreign publications that discusses the advantages of microbiological fertilizers.
To provide the growing population with provision a certain effort is necessary in order to make food production more sustainable, which was declared in 1992 in Rio de Janeiro [3]. Moreover, many sustainable agricultural techniques have already received scientific and practical evidence.
As an example, the article of E. Benizri and B. Amiaud «Relationship between plants and soil microbial communities in fertilized grasslands» may be considered [4]. This article is devoted to the urgent problem of the influence of synthetic fertilizers on the vital functions of soil microorganisms responsible for the stability of the soil of the planet.
The authors conducted an experiment in order to determine the effect of fertilizers on the biodiversity of plants and microorganisms. They set the task to prove that the changes in the diversity of plants and their stages of development occurring due to fertilization have an impact on the availability of soil carbon, and therefore have a negative impact on the composition of soil microorganisms. This work is based on the materials of experiments carried out in the fields, where conventional agricultural work had been carried out for 13 years. Much attention was paid by authors to the microorganisms and plants obtained from the samples analyses, as well as to comparison of the data.
The reached results and conclusions showed that the introduction of artificial fertilizers negatively affects biodiversity of microorganisms. The authors emphasized the importance of biodiversity in grassland ecosystems, which coincides with the findings of other numerous researchers.
In the case when farmlands are exhausted and fertilisers are steel necessary, researchers from Korea suggest the use of compost of waste food, which helps to solve two major problems: recycling of organic residues and reducing of eutrophication. In the article «Effect of Food Waste Compost on Microbial Population, Soil Enzyme Activity and Lettuce Growth» [5] an experiment aiming to clarify the impact of food waste compost on soil microflora, enzymes and plant growth was described. Synthetic fertilizer or conventional compost, or prepared with a special technology food waste compost were added to the soil samples with lettuce sprouts.
Using a variety of techniques the microbal biomass was calculated, their activity was determined and the total nitrogen content of the soil was estimated before and after the experiment. According to the authors’ conclusions, food waste compost is an alternative to chemical fertilizers as it can provide the necessary amount of nutrients, which is supported by the results of other studies in this area.
On the other hand, the authors of the scientific review “The contribution of arbuscular mycorrhizal fungi in sustainable maintenance of plant health and soil fertility” insist that if the soil condition is satisfactory, fertilizer is unnecessary. This work is devoted to the interaction of plants and microorganisms of rhizosphere. The main objective of the study is to prove that the use of mycorrhizal fungi is justified in sustainable agriculture [6].
The search for new biocontrol microbes is ongoing and gaining importance for crops commensurate with a growing world population. It is recognized that continued production of new biocontrol agents will be required to diversify the potential applications of biocontrol and in order to replace commonly used biocontrol products in case resistance develops. Consequently there is a pressing need for cross-disciplinary collaborations and a better and more comprehensive understanding of soil–plant–microbe interaction [7].
The authors note, however, that the use of such technologies requires a theoretical training as various strains may show different properties. The mentioned review describes how environmental factors affect the mycorrhizal fungi, how the genetic diversity of micro symbiotes can be assessed, and provide examples of practical application of these technologies. Materials used in the review prove the positive influence on the reduction of soil born pathogens, fungi mycelium is involved in mechanisms of water retention, and promotes the formation of stable soil systems.
The authors also focus on the abiotic and biotic factors influence, and the importance of fungi biodiversity. In a brief conclusion, the authors emphasize the importance of further study of arbuscular mycorrhizal fungi for their wider application.
Based on the foregoing, it can be concluded that sustainable agriculture has scientific grounds, and is already in progress where people have a perception that one has not only the right to use the environment, but also the duty to preserve it.
References:
1. Lang Wood J. The Effects of Fertilizers & Pesticides // eHow. Available at: http://www.ehow.com/list_7464216_effects-fertilizers-pesticides.html.
2. Meakin S. The Rio Earth summit: summary of the United Nations conference on environment and development // Science and Technology Division, November 1992 / Available at: http://publications.gc.ca/Collection-R/LoPBdP/BP/bp317-e.htm
3. Verma M, Sharma S, Prasad R. Liquid Biofertilizers: Advantages Over Carrier Based Biofertilizers for Sustainable Crop Production // EnviroNews — Newsletter of ISEB India, Vol. 17 No. 2 — April 2011 / Available at: http://isebindia.com/09–12/11–04–4.html
4. Benizri E. & Amiaud B. (2005) Relationship between plants and soil microbial communities in fertilized grasslands // Soil Biology and Biochemistry 37, 2055–2064.
5. Lee J. J., Park R. D., Kim Y. W., Shim J. H., Chae D. H., Rim Y. S., Sohn, B.K., Kim T. H., and Kim K. Y. Effect of Food Waste Compost on Microbial Population, Soil Enzyme Activity and Lettuce Growth // Bioresource Technology, 2004, Volume 93, Pages 21–28.
6. Jeffries P., Gianinazzi S., Perotto K. Turnau and Barea J. M. 2003. The contribution of arbuscular mycorrhizal fungi in sustainable maintenance of plant health and soil fertility // Biology and Fertility of Soils 37:1–16.
7. Pereg L., McMillan M. Scoping the potential uses of beneficial microorganisms for increasing productivity in cotton cropping systems // Soil Biology and Biochemistry. Volume 80, January 2015, Pages 349–358.
