The importance of initial application and reapplication of biochar in the context of soil structure improvement

AbstractIt was shown that the use of biochar provides many benefits to agriculture by improving the whole complex of soil properties, including soil structure. However, the diverse range of biochar effects depends on its physicochemical properties, its application rates, soil initial properties etc. The impacts of biochar, mainly its reapplication to soils and its interaction with nitrogen in relation to water-stable aggregates (WSA) did not receive much attention to date. The aims of the study were: (1) to evaluate the effect of initial application (in spring 2014) and reapplication (in spring 2018) of different biochar rates (B0, B10 and B20 t ha−1) as well as application of biochar with N-fertilizer (40 to 240 kg N ha−1 depending on the requirement of the cultivated crop) on the content of WSA as one of the most important indicators of soil structure quality, (2) to assess the interrelationships between the contents of soil organic matter (SOM) and WSA. The study was conducted in 2017–2019 as part of the field experiment with biochar on Haplic Luvisol at the experimental station of SUA in Nitra, Slovakia. Results showed that initial application as well as reapplication of biochar improved soil structure. The most favorable changes in soil structure were found in N0B20B treatment (with biochar reapplication) at which a significantly higher content of water-stable macro-aggregates (WSAma) (+15%) as well as content of WSAma size fractions of > 5 mm, 5–3 mm, 3–2 mm and 2–1 mm (+72%, +65%, +57% and +64%, respectively) was observed compared to the control. An increase in SOM content, due to both, initial biochar application and its reapplication, significantly supported the stability of soil aggregates, while organic matter including humic substances composition did not.

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A Mathematical Approach to Evaluating the Influence of Various Factors on the Stability of Aggregates in Vertisols

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v53i1.11177 ◽

1969 ◽

Vol 53 (1) ◽

pp. 57-60

Author(s):

M. A. Lugo López ◽

Raúl Pérez Escolar

Keyword(s):

Organic Matter ◽

Soil Aggregates ◽

Aggregate Stability ◽

Correlation Coefficients ◽

Clay Content ◽

Mathematical Approach ◽

Single Factor ◽

Additional Increase ◽

Independent Variable ◽

The Stability

A mathematical approach is presented in this paper to evaluate the influence of such factors as clay content, silt content, organic matter, Ca + Mg, and soluble sodium upon the stability of soil aggregates in a group of Vertisols from the Lajas Valley, P.R. The relationships between aggregate stability and silt and clay were not significant. When the percentage of organic matter was considered as the independent variable, a highly significant correlation coefficient of 0.66 was obtained. Therefore, almost 43 percent of the variability in aggregate stability could be explained on the basis of this single factor. Attempts to increase the percentage of the variability which could be explained in terms of the content of Ca + Mg, and also of soluble sodium, yielded correlation coefficients of 0.70 and 0.74, respectively. Thus, only a slight, but significant, additional increase could be explained when these variables were included.

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Macro ATR-FTIR imaging for better understanding of organic matter dynamics in soil

10.5194/egusphere-egu21-14325 ◽

2021 ◽

Author(s):

Milda Pucetaite ◽

Carlos Arellano ◽

Pelle Ohlsson ◽

Per Persson ◽

Edith Hammer

Keyword(s):

Organic Matter ◽

Soil Structure ◽

Pore Space ◽

Soil Aggregates ◽

Chemical Properties ◽

Spectroscopic Imaging ◽

High Refractive Index ◽

Attenuated Total Reflection ◽

Grand Challenge ◽

Ir Spectroscopic

A grand challenge for mankind is to fight climate change, which involves both reducing and reverting CO2 emissions. Soils store more carbon (C) than the atmosphere and biosphere combined, and it is microorganisms that govern whether C compounds remain in the soil, or whether they are decomposed and released to the atmosphere as CO2. The microbial influence on C cycling range from the way they decompose soil organic matter (SOM) to their contributions on the formation of soil aggregates that are particularly important for physical C stabilization in soils. However, the relationship between the microbial activity, SOM properties and physicochemical microenvironment, including complexity of soil structure (i.e., arrangement of pore space in and between soil aggregates), and how each of these factors contribute to the prolonged residence of C in soils, is not well understood. Therefore, the aim of this work has been to develop and make use of an analytical approach for studying the influence of pore space architecture on microbial SOM decomposition and dynamics by integrating two novel tools in soil sciences &#8211; microfluidic chips, which mimic soil structure, and infrared (IR) spectroscopic imaging, which provides detailed information about chemical properties of materials within these chips.We have used several microchip designs to simulate different levels of complexity of soil pore space. The hypothesis is that the more complex the chip structures &#8211; the less decomposition of SOM will be observed, as more of it will be &#8216;hidden&#8217; from its decomposers within hard-to-reach spaces. For the IR spectroscopic imaging, macro attenuated total reflection (ATR) accessory has been used. In this mode, an ATR element of high refractive index is put in contact with a sample &#8211; the microchip - and total internal reflection signal at the boundary between the element and the sample is recorded. The signal is detected with an imaging focal plane array (FPA) detector and carries information about IR absorptions in the sample. With IR spectra serving as fingerprints for identifying molecules, spatially and temporally resolved observation of chemistry and chemical changes of a SOM substrate initially filling the microchip structures and undergoing decomposition by subsequently inoculated microbial cultures can be made. Our pilot data suggests feasibility of the approach for analysis of complex substrates such as lignin, maize leaves or SOM from real soils and its dependence on the complexity of chip. Evaluating molecular changes in parts of the larger molecules or of the compound mixture under decomposition could even contribute to quantifying, e.g., N mining within the compounds. Eventually, knowing the influence of spatial structure on the decomposition rate and pathways can help us understand how important is the spatial heterogeneity when we study organic matter degradation in soils.

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How dose of biochar and biochar with nitrogen can improve the parameters of soil organic matter and soil structure?

Biologia ◽

10.1515/biolog-2016-0122 ◽

2016 ◽

Vol 71 (9) ◽

Cited By ~ 6

Author(s):

Vladimír Šimanský ◽

Ján Horák ◽

Dušan Igaz ◽

Jerzy Jonczak ◽

Maciej Markiewicz ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Nitrogen Fertilizer ◽

Resource Availability ◽

Soil Structure ◽

Agricultural Soils ◽

Structure Parameters ◽

Soil Resource ◽

Application Rates ◽

Soil Resource Availability

AbstractBiochar application to agricultural soils has a significant potential to influence soil resource availability and thus crop performance. A factorial experiment investigating effects of different biochar application rates combined with nitrogen fertilizer was conducted in field conditions on a Haplic Luvisol. The aim of this study was to evaluate the effects of biochar and biochar combined with fertilization on soil organic matter and soil structure parameters. The treatments comprised combinations of biochar application of 0, 10 and 20 t ha

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Determination of aggregate stability using laser diffraction method in soil with varied texture and carbon content

10.5194/egusphere-egu2020-8507 ◽

2020 ◽

Author(s):

Agnieszka Józefowska ◽

Magdalena Ryżak ◽

Justyna Sokołowska ◽

Karolina Woźnica ◽

Tomasz Zaleski ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Aggregates ◽

Aggregate Stability ◽

Diffraction Method ◽

Laser Diffraction ◽

Organic Additives ◽

Organic Mineral ◽

Active Bacteria ◽

The Stability

Keywords: soil texture, aggregate stability, organic additives, earthworms, microbial activity,Lubbers et al. (2017) emphasised that earthworm by creating macroaggregates increase the amount of organic carbon in the soil. Such macroaggregates contain particulate organic matter, fungal hyphae, or roots, and afterwards, during the decomposition of macroaggregates, the organic matter becomes more resistant to microbial attack (Pulleman et al. 2005). Earthworms, through feeding and burrowing, are important elements in C cycling (Curry and Schmidt 2007). However, the type of introduced organic matter (Huang et al. 2018) and abiotic factors (Six et al. 2004) are equally important in creating stable organic-mineral components as well as the presence of earthworms.A six-month experiment was carried out to test how the soil structure (the stability of soil aggregates) behave under the influence of various organic additives. For each soil, except the reference samples, one of the listed additives was introduced, i.e. straw, straw with fulvic acid, peat (garden soil), compost, compost with active bacteria cultures and straw with fulvic acids, humus and active bacteria cultures. The research was carried out on soils with four types of texture, i.e. sandy, loamy, silty and clayey soil. In the project, three different species of earthworms commonly occurred in Polish soils were a structure-forming factor (Apporectodea rosea, Apporectodea calliginosa and Dendrobena rubillus). After the experiment, the amount of organic carbon in the soil, dissolved organic carbon, humus forms and microbiological activity of the soil were evaluated. The stability of the soil aggregates was determined using two methods: the sieve method (Kemper and Rosenau 1986) and laser diffraction method (Bieganowski et al. 2018),Based on this research it was noted that the aggregate stability is correlated mainly with soil texture. The applied additives had the most significant influence on the transformation of organic carbon in the soil. Soil organic carbon, which may be incorporated into the soil in the form of the organic-mineral colloids, is an essential element in the balance of the carbon in nature. Among the tested additives, organic carbon from compost, peat and compost with active bacteria cultures was in the highest amount associated with fine earth particles (about 36-48%). For comparison, only less than 8.5% of the organic carbon from the straw was incorporated into the mineral part of the soil.Two methods to measures aggregate stability are not comparable for sandy soils. In the wet-sieving method the sand fraction higher than 0.25 mm pretend to be stable aggregates.&#160;The study was financed by The National Science Centre, Poland, grant No. 2017/01/X/ST10/00777, statistical analysis was made based the knowledge and skills achieved during the training: organized as part of the project: Integrated Program of the University of Agriculture in Krak&#243;w, which is co-financed by the European Union (POWR.03.05.00-00-z222/17)

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Controlling Erosion

Handbook of Soils for Landscape Architects ◽

10.1093/oso/9780195121025.003.0009 ◽

1999 ◽

Author(s):

Robert F. Keefer

Keyword(s):

Organic Matter ◽

Organic Material ◽

Soil Structure ◽

Soil Microorganisms ◽

Soil Aggregation ◽

Water Infiltration ◽

Root Penetration ◽

Animal Remains ◽

Decomposition Of Organic Matter ◽

Structure Improvement

Erosion can be controlled by four main means, that is, improving soil structure, covering soil with plants, covering soil with mulch, and using special structures. Soil structure is related to the soil tilth, or physical condition of a soil, with respect to ease of tillage or workability as shown by the fitness of a soil as a seedbed and the ease of root penetration. Other terms relating to soil structure improvement are soil aggregation and the formation of aggregates. Aggregates form when a cementing substance is present in a soil. The most important cementing substances in soil are soil polysaccharides and soil polyuronides produced as by-products from microorganisms during decomposition of organic matter. Other less important cementing substances in soil include clays, Ca, and Fe. Formation of aggregates results in improved water infiltration with reduction in erosion. Decomposition of organic matter in soils can be shown as an equation: . . . Plant and animal remains + O2 + soil microorganisms → CO2 + H2O + elements + humus + synthates + energy . . . The decomposition process has the following features: . . . 1. Oxygen is required; thus soil aeration is important. Anytime a soil is stirred or mixed by cultivation, spading, plowing, some organic matter decomposition occurs. 2. Readily available decomposable organic material is required for the microbes to work on. Green organic material, such as grass clippings, is an excellent substrate. 3. Many different types of soil microorganisms are involved in this process. Decomposition is more rapid in soils at pH 7 (neutral). 4. A product of organic decomposition is humus. Humus has many desirable features that improve a soil for plant growth. 5. Plant or animal remains are not effective in soil aggregation until they begin to decompose. 6. The more rapid the decomposition, the greater effect of soil aggregation. . . . Microbial synthates consist of polymers called “polysaccharides” and “polyuronides.” A polymer is a long-chain compound made up of single monomer units hooked together acting as a unit. The term “poly” means “many” and “saccharide” means “sugar.”

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Stability of soil aggregates and their ability of carbon sequestration

Soil and Water Research ◽

10.17221/106/2013-swr ◽

2014 ◽

Vol 9 (No. 3) ◽

pp. 111-118 ◽

Cited By ~ 8

Author(s):

V. Šimanský ◽

D. Bajčan

Keyword(s):

Organic Matter ◽

Carbon Sequestration ◽

Soil Organic Matter ◽

Soil Aggregates ◽

Size Fraction ◽

Size Fractions ◽

Water Stable Aggregates ◽

Binding Agents ◽

Carbon Reservoir ◽

The Stability

One of the most important binding agents for forming stable aggregates is a soil organic matter (SOM), which can be retained in various size fractions of aggregates. If aggregates are water-resistant, they retain more carbon. Therefore, the aim of this study was to evaluate the stability of aggregates and their ability of carbon sequestration in different soil types and soil management systems in Slovakian vineyards. The highest content of water-stable macro-aggregates (WSAma) was determined in Cambisols, and the lowest in Fluvisols. The highest content of WSAma (size fraction 0.5–3 mm) was determined in Chernozems, decreasing within the following sequence: Fluvisols > Leptosols > Cambisols > Luvisols. The soil type had a statistically significant influence on the re-distribution of soil organic matter in size fractions of water-stable aggregates. The highest content of SOM in water-stable aggregates of the vineyards was determined in grassy strips in-between the vineyard rows in comparison to intensively cultivated rows of vineyard. The highest values of carbon sequestration capacity (CSC) in WSAma were found in Cambisols > Leptosols and the lowest values of CSC were in Fluvisols. The micro-aggregates represented a significant carbon reservoir for the intensively cultivated soils (rows of vineyard). On the other hand, increasing of macro-aggregates (size fraction 0.5–3 mm) was characteristic for grassland soils (between the rows of vineyard).

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CHARACTERIZATION OF BIOGENIC, INTERMEDIATE AND PHYSICOGENIC SOIL AGGREGATES OF AREAS IN THE BRAZILIAN ATLANTIC FOREST

Revista Caatinga ◽

10.1590/1983-21252017v30n107rc ◽

2017 ◽

Vol 30 (1) ◽

pp. 59-67 ◽

Cited By ~ 1

Author(s):

JÚLIO CÉSAR FEITOSA FERNANDES ◽

◽

MARCOS GERVASIO PEREIRA ◽

EDUARDO CARVALHO DA SILVA NETO ◽

THAÍS DE ANDRADE CORRÊA NETO

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Humic Substances ◽

Soil Quality ◽

Secondary Forest ◽

Soil Aggregates ◽

Geometric Mean ◽

Mean Weight Diameter ◽

Successional Stages ◽

The Stability

ABSTRACT Aggregate formation and stability are related to soil quality, contributing significantly to the carbon storage and nutrient maintenance capacities of the soil. Soil aggregates are formed by two different process: physicogenic, related to moistening and drying cycles and input of organic matter; and biogenic, related to the action of macrofauna organisms and roots. The objective this work was to classify aggregates according to their formation process, quantify and compare organic carbon contents in humic substances and assess the stability of aggregates formed by different processes, in areas with different coverage in the Mid Paraiba Valley, Pinheiral, State of Rio de Janeiro, Brazil. Aggregated soil samples were collected at a depth of 0-10 cm, in a Cambisol (Cambissolo Háplico Tb Distrófico) under four plant covers: secondary forest in advanced (SFAS), medium (SFMS) and initial (SFIS) successional stages and managed mixed pasture (MMP). Aggregates were classified and identified into three morphological classes (physicogenic, biogenic and intermediate). The variables evaluated were mean weight diameter (MWD) and geometric mean diameter (GMD) of aggregates, chemical fractions of organic matter, total organic carbon (TOC) and humic substances: humin (C-HUM) humic acid (C-FAH) and fulvic acid (C-FAF). Biogenic aggregates were found in smaller quantities and showed higher TOC, C-HUM and C-FAH, compared to intermediate and physicogenic aggregates. Thus, biogenic aggregates have potential to be used as soil quality indicators for structured environments, which are able to maintain its intrinsic formation processes.

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The Formation Mechanism Of Mudflat Soil Aggregates Driven By Exogenous Organic Matters

10.5194/egusphere-egu2020-12309 ◽

2020 ◽

Author(s):

Yanchao Bai ◽

Chuanhui Gu ◽

Yuhua Shan

Keyword(s):

Organic Matter ◽

Microbial Diversity ◽

Crop Production ◽

Soil Structure ◽

Soil Aggregates ◽

Organic Matter Content ◽

Matter Content ◽

Arable Soil ◽

Nutrient Level ◽

Salt Reduction

Mudflats are valuable land resources located in the interaction zone between land and sea and are found in many parts of the world. The newly reclaimed mudflats are high in salinity and low in fertility as indicated by poor soil structure, extremely low organic matter content, low nutrient level and lack of microbial diversity, which is not suitable for cultivation. The keys to mudflat reclamation to arable lands are (1) to reduce salinity and (2) to increase the soil organic matter content and thus soil fertility. The former determines whether the reclaimed mudflat can be used for crop production and the latter determines whether the crop production is sustainable. On the basis of salt reduction measures, adding exogenous organic matter to drive the formation of soil aggregates in mudflat saline-alkali soil is a prerequisite for inhibiting the return of salt, improving fertility and promoting the transformation of mudflat reclaimed soil into arable soil. Research on the formation of clustered soil aggregates during the evolution of mudflat soil into arable soil should focus on the regulatory, formation, and stability mechanism of different exogenous organic matter. In addition, exploration of the effects of the special properties of mudflat soil, e.g., high salinity, high pH, and low microbial diversity, on the formation and stability of soil aggregates is necessary. The regularity and regulation of soil structure and fertility evolution of the mudflat driven by exogenous organic matter were clarified. Research on soil aggregate formation not only enrich the basic theory of soil quality evolution of mudflat, but also have practical guiding significance for the maturation of mudflat soil.

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Effects of irrigation and soil management for fodder crops on root zone conditions in a red-brown earth

Soil Research ◽

10.1071/sr9840207 ◽

1984 ◽

Vol 22 (2) ◽

pp. 207 ◽

Cited By ~ 11

Author(s):

WK Mason ◽

DR Small ◽

KE Pritchard

Keyword(s):

Organic Matter ◽

Root System ◽

Soil Water ◽

Surface Soil ◽

Root Zone ◽

Soil Aggregates ◽

Soil Management ◽

Rooting Depth ◽

Fodder Crops ◽

The Stability

The irrigated red-brown earths in northern Victoria have traditionally been considered unsuitable for intensive cropping owing to unstable soil structure. This experiment was established to determine whether management systems for continuous double cropping or crop/lucerne rotations could be developed for these soils. A range of tillage levels, flood or furrow irrigation treatments and organic matter additions were imposed in December 1981. Soil strength, measured with a field penetrometer, has been significantly reduced by both surface soil management and deep ripping. The stability of surface soil aggregates has been significantly increased by reducing tillage, by avoiding the rapid wetting associated with flood irrigation and by the addition of organic matter. However, there has been no increase in rooting depth or activity of maize crops, as indicated by soil water extraction patterns and midday leaf water potential data, in response to the treatments imposed. However, lucerne rapidly developed an active root system, deeper in the profile than maize. This deeper root system increased the soil water supply for lucerne by approximately 50 mm.

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Nutrient and Stoichiometric Characteristics of Aggregates in a Sloping Farmland Area under Different Tillage Practices

Sustainability ◽

10.3390/su13020890 ◽

2021 ◽

Vol 13 (2) ◽

pp. 890

Author(s):

Jie Zhang ◽

Yaojun Liu ◽

Taihui Zheng ◽

Xiaomin Zhao ◽

Hongguang Liu ◽

...

Keyword(s):

Organic Matter ◽

Size Distribution ◽

Soil Aggregates ◽

Soil Aggregate ◽

Elemental Content ◽

Stoichiometric Ratio ◽

Longitudinal Ridge ◽

Stoichiometric Ratios ◽

Sloping Farmland ◽

Ridge Tillage

Sloping farmland is prevalent in hilly red soil areas of South China. Improper tillage patterns induce decreased soil organic matter, soil aggregate breakdown, and nutrient imbalance, thereby restricting crop production. However, the stoichiometric characteristics could reflect the nutrient availability which was mostly studied on bulk soil. The stoichiometric characteristics of soil aggregates with multiple functions in farmlands has rarely been studied. The study was to reveal the impact of tillage patterns on the size distribution, nutrient levels, and stoichiometric ratios of soil aggregates after 20 years’ cultivation. Soil samples of 0–20 cm and 20–40 cm from five tillage patterns, bare-land control (BL), longitudinal-ridge tillage (LR), conventional tillage + straw mulching (CS), cross-ridge tillage (CR), and longitudinal-ridge tillage + hedgerows (LH) were collected. The elemental content (C, N and P) and soil aggregate size distribution were determined, and the stoichiometric ratios were subsequently calculated. Through our analysis and study, it was found that the nutrient content of >2 mm soil aggregates in all plots was the highest. In the hedgerow plots, >2 mm water-stable soil aggregate content was increased. Therefore, LH plots have the highest content of organic matter and nutrients. After 20 years of cultivation, stoichiometric ratio of each plot showed different changes on soil aggregates at different levels. the C:N, C:P, and N:P ratios are lower than the national average of cultivated land. Among of them, the stoichiometric ratio in the LH plot is closer to the mean and showed better water-stable aggregate enhancement. Therefore, longitudinal-ridge tillage + hedgerows can be recommended as a cultivation measure. This study provides a reference for determining appropriate tillage measures, balancing nutrient ratios, and implementing rational fertilization.

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