It is known that the soil is an open and complex system wOrganicBloom_Ingal_UFSM (10)ith continuous exchange of matter and energy with the environment due to the many relations between the subsystems that compose it (plants, organisms and mineral matter). Thus, plants play an important role in adding to soil organic compounds, synthesized in photosynthesis, using solar energy, carbon dioxide (CO2) from the air, water and soil nutrients. Now, organisms, mainly heterotrophic microorganisms, obtain energy for their development through the decomposition of plant residues and soil organic matter, releasing carbon dioxide (CO2) into the atmosphere, nutrients, and numerous secondary organic compounds derived from microbial metabolism, which, hence became part of the organic matter in the soil.

Thus, the soil organic matter (SOM) can be considered a key indicator of soil quality, being rather sensitive to changes in management systems. Every variety of organic substances in soil can be divided into two groups: organic substances of individual nature and humic substances. The first group is composed of organic debris, featuring its decomposition products or the products of the vitalactivity of the live population, in other words, in mineral soils constitute about 10-15% of the total reserves of organic matter. While the second group comprises the major portion of the organic portion of the soil, 85-95% of the total reserves of humus.

These humic substances are related to the physical-chemical properties of soils and interaction with metals (immobilization) and organic compounds. They have a great capacity to retain water in the soil, through the formation of aggregates. With colloidal property of these substances, the aggregation of the molecules by covalent bonds with hydrogen, forming spongy structures with large voids, permitting retain high amounts of water in the soil, for slowly release it to the plant.

Humic substances are fractionated into fulvic acids (soluble in acid or alkaline pH), humic acids (soluble in alkaline pH) and humin (insoluble at any pH). According to studies, it is considered that about 80% of the soil organic carbon is contained in humic substancorganic_bloom_garrafaes, particularly in humin. Moreover, they have the ability to interact with clays and alter the physical, chemical and biological properties of the soil, playing an important role in the soil fertility and structure.

Through the field experiments is possible to observe the benefits of using humic acid in agriculture, since it allows to increase the absorption of nutrients and improve soil structure reflecting directly in production, yield and quality of crops. Also provide the availability of phosphorus adsorbed in the fraction of clay or complexed ions, unavailable for most vegetables. In the case of complexed calcium ions, which form the precipitated calcium phosphate the humic acids becomes more complex (sequester) the soluble calcium and protect the phosphates of calcium phosphate interaction, in the adsorption of the phosphate anion, leaving it available to plant uptake (FILHO et al., 2002).

Report of Traina et al. (1986), cited by Fontana et al. (2008), was found that the humic substances of organic matter are capable of solubilizing phosphates of iron and aluminum, thus reducing the precipitation of phosphate ions Fe and Al and to reduce the adsorption of phosphorus per oxidroxides of iron and aluminum. These elements can adsorb humic substances with great energy and compete with phosphate for the same absorption sites.

Currently, there are numerous products on the market capable of providing humic and fulvic acids to soil and crops. Among them, we highlight the Organic Bloom fertilizer, organic source of phosphorus and amino acids, which has in its composition humic substances that helps plants uptake process, besides making the improvements in soil structure.

* Fernanda Mugnol – Agronomist Eng. – CREA RS 178798. Post graduation Student in MBE Expertise, Environmental Management and Auditing

References:

Coelho, Marino Salgarello et al. Qualidade da matéria orgânica de solos sob cultivo de café consórciado com adubos verdes. Rev. Bras. Ciênc. Solo, Dez 2013, vol.37, no.6, p.1576-1586.

Dobbss, Leonardo Barros et al. Caracterização química e espectroscópica de ácidos húmicos e fúlvicos isolados da camada superficial de latossolos brasileiros. Rev. Bras. Ciênc. Solo, Fev 2009, vol.33, no.1, p.51-63.

Filho, A.V.S; Ishikawa, M. V. S. Importância das Substâncias Húmicas para a Agricultura, Empresa Estadual de Pesquisa Agropecuária da Paraíba, Anais- 2002

Fontana et al. Fósforo remanescente e correlação com as substâncias húmicas em um latossolo vermelho sob diferentes sucessões de cultura em plantio direto. Rev Bras. Agrociência, Pelotas, v.14, n.1, p.161-166, jan-mar, 2008

Lauana Lopes dos Santos et al. Partição de substâncias húmicas em solos brasileiros. Rev. Bras. Ciência do. Solo, 37:955-968, 2013

Lovato, T. et al. Adição de carbono e nitrogênio e sua relação com os estoques no solo e com o rendimento do milho em sistemas de manejo. Rev. Bras. Ciênc. Solo, Fev 2004, vol.28, no.1, p.175-187.

Rosa, Carla Machado da et al. Conteúdo de carbono orgânico em planossolo háplico sob sistemas de manejo do arroz irrigado. Rev. Bras. Ciênc. Solo, Out 2011, vol.35, no.5, p.1769-1776. ISSN 0100-0683

Organic Bloom: influence of humic substances in organic matter *

Deixe um comentário

O seu endereço de e-mail não será publicado. Campos obrigatórios são marcados com *