Environmental Factors Affecting the Mineralization of Crop Residues

Abstract

The aim of this article is to present the issues related to the significance of microorganisms in the mineralization of crop residues and the influence of environmental factors on the rate of this process. Crop residues play a very important role in agriculture because they can be used both as an environment-friendly waste management strategy and as a means of improving soil organic matter. The inclusion of crop residues in the soil requires appropriate management strategies that support crop production and protect the quality of surface water and groundwater. Crops need nutrients for high yields; however, they can only absorb ionic forms of elements. At this point, the microorganisms that convert organically bound nitrogen, phosphorus, and sulfur into soluble NH4+, NO3−, H2PO4−, HPO42−, and SO42− ions are helpful. Mineralization is the transformation of organic compounds into inorganic ones, which is a biological process that depends on temperature, rainfall, soil properties, the chemical composition of crop residues, the structure and composition of microbial communities, and the C:N ratio in soil after the application of plant matter. An adjustment of the values of these factors enables us to determine the rate and direction of the mineralization of crop residues in soil.

Impacts of crop residues on soil health: a review

“…Lignin is a phenolic complex polymer formed by crosslinking of three major components: p-coumaryl, coniferyl, and sinapyl alcohols. In cell walls, cellulose is surrounded by a monolayer of hemicellulose and embedded in a matrix of hemicellulose and lignin, which form stable complex 3-dimensional structure (Figure 1) [15][16][17].…”

“…They help alleviating imbalances of nutrients in farm soil and making up for drawbacks of inorganic fertilizers. The release rate and content of nutrient are related to the properties of crop residues (C/N ratio and chemical composition), the climate (temperature and moisture), the soil conditions (pH and water content) and the method of applying crop residues into soil (direct and indirect) [15]. Usually, it is assumed that C/N ratio greater than 25:1 leads to the rapid immobilization of inorganic nitrogen while lower C/N ratio results in mineralization.…”

The Significance of Microbial Transformation of Nitrogen Compounds in the Light of Integrated Crop Management

“…According to Myrold and Posavatz [114], due to the threadlike appearance of cells, fungi usually take up nitrogen in the form of low motility NH 4 + ions, whereas bacteria exhibit greater potential for using NO 3 − , especially in the absence of exogenous organic carbon sources. According to Grzyb et al [115], the immobilization of nitrogen by soil microorganisms significantly affects the content of inorganic nitrogen in soil and thus influences the degree of nutrition and productivity of plants. According to Grzebisz [116] and Grzyb [115], a C:N ratio ranging from 25:1 to 30:1 is often considered to be the critical point between immobilization and mineralization.…”

“…According to Grzyb et al [115], the immobilization of nitrogen by soil microorganisms significantly affects the content of inorganic nitrogen in soil and thus influences the degree of nutrition and productivity of plants. According to Grzebisz [116] and Grzyb [115], a C:N ratio ranging from 25:1 to 30:1 is often considered to be the critical point between immobilization and mineralization. When crop residues with a high C:N ratio (above 30:1) enter soil, nitrogen in the microbial biomass is immobilized (nitrogen proteinization process), and it becomes less available to plants.…”

Biostimulants Managed Fungal Phytopathogens and Enhanced Activity of Beneficial Microorganisms in Rhizosphere of Scorzonera (Scorzonera hispanica L.)

“…This is associated with the necessity to obtain a large and good-quality root yield [10,15]. The health-promoting properties of root vegetables, including scorzonera, is determined, among others, by physical and biochemical properties of the arable environment [10,16] and biodiversity of soil microorganisms, especially the presence of soil-borne pathogens [6,17,18]. Despite the relatively rare cultivation of scorzonera, information about infectious agents that threaten this species is available in the literature.…”