Controlling Erosion

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.”

scholarly journals The living soil ? an agricultural perspective

2007 ◽  
Vol 28 (3) ◽  
pp. 104 ◽  
Author(s):  
Margaret M Roper ◽  
Vadakattu V S R Gupta
Keyword(s):  
Biological Control ◽  
Porous Medium ◽  
Organic Matter ◽  
Plant Growth ◽  
Ecosystem Function ◽  
Soil Structure ◽  
Biological Function ◽  
Decomposition Of Organic Matter ◽  
Wide Range ◽  
Biodiversity And Ecosystem Function

Soils are much more than a porous medium for supporting plant growth. Soils are living, because they contain a wide range of microorganisms including bacteria, fungi, algae, protozoa, nematodes and other fauna including microarthropods, macroarthropods, termites and earthworms. All play a crucial role in the biological function of soils including decomposition of organic matter, nutrient transformations, biological control, development of soil structure to mention a few. Until recently the complexity of life in the soil has been difficult to unravel, but new DNA and biochemical tools are providing insights into its phenotypic and functional diversity and capability, and should drive the development of managements that nurture biodiversity and ecosystem function.

Measuring Soil Loss and Subsequent Nutrient and Organic Matter Loss on Farmland

2017 ◽  
Author(s):  
Vito Ferro ◽  
Vincenzo Bagarello
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Loss ◽  
Soil Structure ◽  
Overland Flow ◽  
Organic Matter Content ◽  
Matter Content ◽  
Water Infiltration ◽  
Surface Erosion ◽  
Rill Erosion

Field plots are often used to obtain experimental data (soil loss values corresponding to different climate, soil, topographic, crop, and management conditions) for predicting and evaluating soil erosion and sediment yield. Plots are used to study physical phenomena affecting soil detachment and transport, and their sizes are determined according to the experimental objectives and the type of data to be obtained. Studies on interrill erosion due to rainfall impact and overland flow need small plot width (2–3 m) and length (< 10 m), while studies on rill erosion require plot lengths greater than 6–13 m. Sites must be selected to represent the range of uniform slopes prevailing in the farming area under consideration. Plots equipped to study interrill and rill erosion, like those used for developing the Universal Soil Loss Equation (USLE), measure erosion from the top of a slope where runoff begins; they must be wide enough to minimize the edge or border effects and long enough to develop downslope rills. Experimental stations generally include bounded runoff plots of known rea, slope steepness, slope length, and soil type, from which both runoff and soil loss can be monitored. Once the boundaries defining the plot area are fixed, a collecting equipment must be used to catch the plot runoff. A conveyance system (H-flume or pipe) carries total runoff to a unit sampling the sediment and a storage system, such as a sequence of tanks, in which sediments are accumulated. Simple methods have been developed for estimating the mean sediment concentration of all runoff stored in a tank by using the vertical concentration profile measured on a side of the tank. When a large number of plots are equipped, the sampling of suspension and consequent oven-drying in the laboratory are highly time-consuming. For this purpose, a sampler that can extract a column of suspension, extending from the free surface to the bottom of the tank, can be used. For large plots, or where runoff volumes are high, a divisor that splits the flow into equal parts and passes one part in a storage tank as a sample can be used. Examples of these devices include the Geib multislot divisor and the Coshocton wheel. Specific equipment and procedures must be employed to detect the soil removed by rill and gully erosion. Because most of the soil organic matter is found close to the soil surface, erosion significantly decreases soil organic matter content. Several studies have demonstrated that the soil removed by erosion is 1.3–5 times richer in organic matter than the remaining soil. Soil organic matter facilitates the formation of soil aggregates, increases soil porosity, and improves soil structure, facilitating water infiltration. The removal of organic matter content can influence soil infiltration, soil structure, and soil erodibility.

scholarly journals Soil aggregation and organic carbon of Oxisols under coffee in agroforestry systems

2014 ◽  
Vol 38 (1) ◽  
pp. 278-287 ◽  
Author(s):  
Gabriel Pinto Guimarães ◽  
Eduardo de Sá Mendonça ◽  
Renato Ribeiro Passos ◽  
Felipe Vaz Andrade
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Aggregation ◽  
Root Penetration ◽  
Conventional System ◽  
Physical Quality ◽  
Soil Physical Quality ◽  
Organic Coffee ◽  
On Farm ◽  
The Impact

Intensive land use can lead to a loss of soil physical quality with negative impacts on soil aggregates, resistance to root penetration, porosity, and bulk density. Organic and agroforestry management systems can represent sustainable, well-balanced alternatives in the agroecosystem for promoting a greater input of organic matter than the conventional system. Based on the hypothesis that an increased input of organic matter improves soil physical quality, this study aimed to evaluate the impact of coffee production systems on soil physical properties in two Red-Yellow Oxisols (Latossolos Vermelho-Amarelos) in the region of Caparaó, Espirito Santo, Brazil. On Farm 1, we evaluated the following systems: primary forest (Pf1), organic coffee (Org1) and conventional coffee (Con1). On Farm 2, we evaluated: secondary forest (Sf2), organic coffee intercropped with inga (Org/In2), organic coffee intercropped with leucaena and inga (Org/In/Le2), organic coffee intercropped with cedar (Org/Ced2) and unshaded conventional coffee (Con2). Soil samples were collected under the tree canopy from the 0-10, 10-20 and 20-40 cm soil layers. Under organic and agroforestry coffee management, soil aggregation was higher than under conventional coffee. In the agroforestry system, the degree of soil flocculation was 24 % higher, soil moisture was 80 % higher, and soil resistance to penetration was lower than in soil under conventional coffee management. The macroaggregates in the organic systems, Org/In2, Org/In/Le2, and Org/Ced2 contained, on average, 29.1, 40.1 and 34.7 g kg-1 organic carbon, respectively. These levels are higher than those found in the unshaded conventional system (Con2), with 20.2 g kg-1.

Interactions in the soil-plant-water system as a basis for landscape-adoptive planning of carbon sequestration in agroecosystems along natural moisture gradient

2021 ◽  
Author(s):  
Alla Yurova ◽  
Valery Kiryushin ◽  
Anna Yudina
Keyword(s):  
Organic Matter ◽  
Carbon Sequestration ◽  
Land Management ◽  
Soil Structure ◽  
Weather Condition ◽  
C Sequestration ◽  
Mineral Weathering ◽  
Water Infiltration ◽  
Pollution Level ◽  
Zone Model

&lt;p&gt;The key for implementation of sustainable development goals in land management is in multifunctional paradigm of landscape usage. A lot of scientific efforts were done since 1980s (e.g. Kiryushin, 2019) to develop a landscape-adaptive system which is in essence addressing&lt;/p&gt;&lt;p&gt;1) spatial distribution of plant varieties and farm operations adapted to topographical and lithological landscape features 2) temporal tuning of crop phenology to regional and even local weather conditions. This system proved especially useful in increasing the yield and yet reducing pollution level in experimental settings. However, there were no boost of implementation in the country of origin-Russia- due to number of reasons, social and economical included. The rapid growth of carbon tax and carbon market provides a new window of opportunity for landscape adaptive agriculture, but only in case documented benefit for carbon sequestration could be shown. Here we present theoretical proof of concept based on integrated critical zone model, 1D-ICZ (Giannakis et al, 2017), that couples computational modules for soil organic matter dynamics, soil aggregation and structure dynamics, bioturbation, plant productivity and nutrient uptake, water flow, solute speciation and transport, and mineral weathering kinetics. The model was applied to study C sequestration soil function along the regional natural soil moisture and temperature gradient. Calibration was done for three soil types (Retisols, Phaeozems, Chernozems) of increasing moisture deficits representing the well-drained landscape shoulder positions with an automorphic regime and hydromorphic footslope positions. The scenario simulation included the change in relative frequency of weather condition with low and extremely low, but also high end extremely high precipitation (from IPCC set of climate models). The model explicitly couples water infiltration storage and supply to soil structure and pedotransfer functions varying with meteorological conditions. This interaction allowed to select the current soil configuration and usage or structural and biogeochemical change in each soil and each scenario that are presumably most beneficial for C sequestration. The role of climate variables was maximum for automorphic regime and decreased with the decreasing distance to ground water. The soil textural, structural, and chemical properties on opposite played the major role on footslope positions. Accordingly, optimal land management option that promote corresponding soil structure, organic matter input and soil climate is proposed and discussed in balance with other soil functions.&lt;/p&gt;

Inoculation of bacteria for the amelioration of sandy soil under drought

2020 ◽  
Author(s):  
Violeta Carmen Angulo Fernández ◽  
Mariet Hefting ◽  
George Kowalchuk
Keyword(s):  
Soil Compaction ◽  
Biofilm Formation ◽  
Soil Structure ◽  
Soil Microorganisms ◽  
Soil Aggregate ◽  
Soil Aggregation ◽  
Bacterial Strains ◽  
Mean Weight Diameter ◽  
Microbial Strains ◽  
The Mean

&lt;p&gt;Soil degradation represents a pressing worldwide problem that is being accelerated by processes of erosion, depletion of soil organic matter, soil compaction, acidification, salinization, and drought. Soil microorganisms can influence soil aggregation via a range of mechanisms such as the production of exopolysaccharides and other extracellular matrix polymers such those involved in biofilm formation. In this study, we south to use bacteria harboring specific traits to enhance soil aggregation. To this end, 120 bacterial strains were isolated from an experiment field under drought conditions and tested for their ability to grow under drought, salinity tolerance, rapid growth, biofilm, and exopolysacharides production. Based upon this trait assessment, 24 strains were further tested at two moisture levels for their ability to impact soil structure after 8 weeks of incubation at 25&amp;#186;C. The mean weight diameter (MWD) of water-stable aggregates and carbohydrates were determined for treated soils. Three strains were shown to impact soil aggregate properties at the higher moisture content: one affiliated with &lt;em&gt;Bacillus &lt;/em&gt;niacini, one affiliated with &lt;em&gt;Paenarthrobacter &lt;/em&gt;nitroguajacolicus and one of unclear classification. The first of these strains also affected soil structure at the lower moisture level. This &lt;em&gt;B. &lt;/em&gt;niacini strain also increased the carbohydrate content of the soil, as did two other strains, related to &lt;em&gt;B. &lt;/em&gt;wiedmannii and &lt;em&gt;B. &lt;/em&gt;aryabhattai, respectively. However, no positive correlation was observed between the MWD and the production of carbohydrates in soil. Our results suggest that soil inoculation with specific microbial strains can improve soil structure.&lt;/p&gt;

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

2021 ◽  
Vol 69 (1) ◽  
pp. 87-97
Author(s):  
Martin Juriga ◽  
Elena Aydın ◽  
Ján Horák ◽  
Juraj Chlpík ◽  
Elena Y. Rizhiya ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Structure ◽  
Soil Aggregates ◽  
Diverse Range ◽  
Structure Quality ◽  
Experimental Station ◽  
Initial Application ◽  
Application Rates ◽  
Structure Improvement ◽  
The Stability

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.

The Influence of Organic Matter on Soil Aggregation and Water Infiltration

jpa ◽  
1989 ◽  
Vol 2 (4) ◽  
pp. 290-299 ◽  
Author(s):  
Michael Boyle ◽  
W. T. Frankenberger ◽  
L. H. Stolzy
Keyword(s):  
Organic Matter ◽  
Soil Aggregation ◽  
Water Infiltration
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