scholarly journals Stabilization of Organic Matter by Biochar Application in Compost-amended Soils with Contrasting pH Values and Textures

2015 ◽  
Vol 7 (10) ◽  
pp. 13317-13333 ◽  
Author(s):  
Shih-Hao Jien ◽  
Chung-Chi Wang ◽  
Chia-Hsing Lee ◽  
Tsung-Yu Lee
Author(s):  
Sumaya Sharmin ◽  
Md. Abdul Kader ◽  
Md. Rezwanul Islam ◽  
Muhiuddin Faruquee

Aims: To examine the changes in pH and Eh values of terrace soils during anaerobic incubation when amended with different organic materials, and to study N, P and S release from different manure and bio-slurry in terrace soil under anaerobic condition. Study Design: The experiment was carried out following Complete randomized design (CRD) with two replications. Place and Duration of Study: A laboratory incubation study was conducted in Soil Science Laboratory, Bangladesh Agricultural University, Mymensingh in December 2014 for 98 days. Methodology: The surface (0-15 cm) soil sample was collected from rice growing field of a selected area of Bhaluka, Mymensingh. The incubation study was carried out using four different sources of organic manures with two replications and five treatment combinations. The changes in soil pH, Eh and release pattern of N, P, and S from some organic materials in terrace soil under anaerobic incubation were investigated during December 2014 to April 2015. The soil was amended with all the treatments at 2g 100 g-1 (air dry basis) soil and incubated for 14 weeks at 25° C. The N, P and S release were determined by the measurement of NH4-N, phosphate P and SO4-S on destructive sampling at every two weeks. Results: The pH values increased at initial stage but gradually decreased over time to neutral and the soil became reduced with the advancement of incubation, it varies (1-3 weeks) depending on the quality of organic matter used. The reduction potential showed a significant variation among the treatments. Overall, when the pH values were averaged over the weeks, the highest pH value was measured in poultry bio-slurry (PB) amended soil followed by poultry manure (PM), cow dung bio-slurry (CDB) and cow dung (CD) amended soils and the lowest was in control. In case of Eh, the most negative (-133.08) Eh value was measured in PM amended soil followed by poultry bio-slurry (PB), CD and CDB amended soils. Control soil had comparatively positive Eh value. At the end of incubation, the highest amount of NH4-N found in CDB followed by CD, PM, PB and the lowest was in control; the highest amount of phosphate P found in PB followed by PM, control, CDB and CD; the highest amount of SO4-S found in PB followed by PM, CD, CDB and the lowest was in control. Conclusion: PB is the best source of organic amendment with respect to release of P and S, whereas CDB showed the best performance in release of N. Nutrient release and availability in reduced environment in terrace soil are a function of soil redox chemistry which is influenced by the quality and quantity of organic matter.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 628
Author(s):  
Hassan E. Abd Elsalam ◽  
Mohamed E. El- Sharnouby ◽  
Abdallah E. Mohamed ◽  
Bassem M. Raafat ◽  
Eman H. El-Gamal

Sewage sludge is an effective fertilizer in many soil types. When applied as an amendment, sludge introduces, in addition to organic matter, plant nutrients into the soil. When applied for cropland as a fertilizer, the mass loading of sewage sludge is customarily determined by inputs of N and/or P required to support optimal plant growth and a successful harvest. This study aims to examine the changes in organic matter contents and nitrogen forms in sludge-amended soils, as well as the growth of corn and faba bean plants. The main results indicated that there were higher responses to the corn and faba bean yields when sludge was added. Levels of organic carbon in soil were higher after maize harvest and decreased significantly after harvesting of beans, and were higher in sludge amended soils than unmodified soils, indicating the residual effect of sludge in soil. NO3−-N concentrations were generally higher in the soil after maize harvest than during the plant growth period, but this trend was not apparent in bean soil. The amounts of NH4+-N were close in the soil during the growth period or after the maize harvest, while they were higher in the soil after the bean harvest than they were during the growth period. Total nitrogen amounts were statistically higher in the soil during the growth period than those collected after the corn harvest, while they were approximately close in the bean soil. The total nitrogen amount in corn and bean leaves increased significantly in plants grown on modified sludge soil. There were no significant differences in the total nitrogen levels of the maize and beans planted on the treated soil.


2021 ◽  
Author(s):  
Hannah Binner ◽  
Timothy Sullivan ◽  
Maria E. Mc Namara

<p>Soil contamination is widespread across Europe. In particular, contamination of urban soils by metals is poorly characterised. This is a major environmental concern, especially given that urban recreational amenities may be located on former industrial sites and/or may possess ex situ soils derived from industrial areas. We surveyed soils from nine urban recreational sites (15 samples per site) in Cork city in order to assess the degree of metal contamination. The results show that Pb concentrations exceed national background levels in all soil samples from all sites by a mean of 600 % and at least 140 %. Mn, Fe and Zn are enriched above background levels in all soil samples from three (Mn and Fe) to five (Zn) of the sites and, at the remaining sites, show 7 – 14 localised hotspots. Similar hotspots characterise Cu, Rb and Sr, which each exceed background levels at eight or more sampling locations at four sites. Co, Ni, As and Sn concentrations exceed background levels in at least three hotspots at each of three to six sites. Overall, metal concentrations are highest in the sites closest to the city centre, reflecting diverse sources that potentially include traffic and current and historical domestic coal burning and industry. At each urban site, the element grouping Zn and Pb recurs in 50 to 80 % of locations and enrichment in the element grouping Mn, Fe, Cu, Zn and Pb recurs in approx. 50 % of locations; Ni and As recur in approx. 10 % of the locations. At three sites, elevated concentrations of Mn, Fe, Cu, Zn and Pb are associated with high LOI (Loss-on-ignition) values – a proxy for the amount of soil organic matter present – and near-neutral pH values. Conversely, low LOI and acidic pH values are associated with lower concentrations of these elements. This indicates that soil metal concentrations are influenced by the amount of organic matter present and by pH.  Future analyses and experiments will further investigate links between soil organic matter and metal concentrations.</p>


2009 ◽  
Vol 6 (1) ◽  
pp. 491-514 ◽  
Author(s):  
R. F. Krachler ◽  
R. Krachler ◽  
A. Stojanovic ◽  
B. Wielander ◽  
A. Herzig

Abstract. To date, little is known about the pH-stimulated mineralization of organic matter in aquatic environments. In this study, we investigated biodegradation processes in alkaline waters. Study site is a large shallow soda lake in Central Europe (Neusiedler See/Ferto). The decomposition rate of plant litter was measured as a function of pH by incubating air-saturated lake-water samples in contact with Phragmites litter (leaves) from the littoral vegetation. All samples showed high decomposition rates (up to 32% mass loss within 35 days) and a characteristic two-step degradation mechanism. During the degradation process, the solid plant litter was dissolved forming humic colloids. Subsequently, the humic colloids were mineralized to CO2 in the water column. The decomposition rate was linearly related to pH. Increasing pH values accelerated significantly the leaching of humic colloids as well as the final degradation process. The observed two-step mechanism controls the wetland/lake/air carbon fluxes, since large quantities of humic colloids are currently produced in the reed belt, exported through wind-driven circulations and incorporated into the open lake foodweb. At present, the lake is rapidly shrinking due to peat deposition in the littoral zone, whereas it has been resistant to silting-up processes for thousands of years. In order to investigate the cause of this abrupt change, the chemical composition of the lake-water was measured during 1995–2007. A thorough analysis of these data revealed that major lake-water discharges through the lake's artificial outlet channel led to a decline in salinity and alkalinity. According to our estimates, the lake's original salinity and alkalinity was 70–90% higher compared to the present conditions, with the consequence of substantially lower pH values in the present lake. The observed pH dependence of reed litter biodegradation rates points to a causal connection between low pH values and accumulation of peat in the lake basin. Our results suggest that the pH stimulated remineralisation of organic matter plays a major role in maintaining the long-term integrity of saline lake/wetland systems.


1982 ◽  
Vol 99 (3) ◽  
pp. 465-470
Author(s):  
J. E. Cook ◽  
R. J. Wilkins ◽  
R. F. Wilson

SUMMARYCrops of perennial ryegrass and lucerne were each ensiled without additives and after the addition of paraformaldehyde to provide about 0·1, 0·2 or 0·4% HCHO/t crop fresh weight. The ryegrass and lucerne silages were offered ad libitum to sheep in separate experiments of identical design.All theryegrass silages were well preserved with low pH values, the level of butyric acid was very low and ammonia-N comprised less than 8% of total N. The lucerne silage made without additive had a pH of 5 and acetic acid comprised the major part of the total fermentation acids. Ammonia-N comprised over 12% of total N. All levels of paraformaldehyde addition restricted fermentation in both crops and led to an increase in the proportion of total N which was insoluble in hot water.Voluntary intake of organic matter (OM) was higher for the lucerne than for the ryegrass silages but digestible organic matter (DOM) intake was higher for the ryegrass. Intakes of OM and DOM were not significantly affected by paraformaldehyde treatment. The addition of paraformaldehyde significantly depressed apparent digestibility of OM and cellulose with the ryegrass but had less effect with the lucerne. Nitrogen digestibility was significantly depressed in both crops at all paraformaldehyde levels. Paraformaldehyde addition resulted in increased faecal N output and decreased urinary N, but retention of N was not significantly affected.The lack of response in feeding value to paraformaldehyde treatment may have been due to the relatively high intake and N retention of the untreated silages which were fairly well preserved.


1963 ◽  
Vol 9 (4) ◽  
pp. 555-561 ◽  
Author(s):  
Zofia Maciejowska ◽  
E. B. Williams

The fungus flora developing in cellulose-amended and non-amended soils of neutral pH at moisture levels of 60, 70, and 80% water-holding capacity (WHC) was investigated. A distinct, successive development of three species, Staphylotrichum coccosporum, Coccospora agricola, and Sependonium sp., was observed in soil held at 60% WHC. More species developed in soil held at 70% WHC, and they could effectively coexist during cellulose decomposition. S. coccosporum developed in smaller numbers at 80% WHC than at 60 and 70% WHC. Sepedonium sp. was associated with cellulose decomposition only at 80% WHC. Species of Trichoderma, Monilia, and Fusarium developed better at high moisture levels. It was concluded that available inoculum and the moisture of soils of similar pH values are major factors in determining composition of the microflora of cellulose-amended soil.


2020 ◽  
Author(s):  
Beatrice Giannetta ◽  
Ramona Balint ◽  
Daniel Said-Pullicino ◽  
César Plaza ◽  
Maria Martin ◽  
...  

<p>Redox-driven changes in Fe crystallinity and speciation may affect soil organic matter (SOM) stabilization and carbon (C) turnover, with consequent influence on global terrestrial soil organic carbon (SOC) cycling.<span> </span>Under reducing conditions, increasing concentrations of Fe(II) released in solution from the reductive dissolution of Fe (hydr)oxides may accelerate ferrihydrite transformation, although our understanding of the influence of SOM on these transformations is still lacking.<span> </span></p><p>Here, we evaluated abiotic Fe(II)-catalyzed mineralogical changes in Fe (hydr)oxides in bulk soils and size-fractionated SOM pools (for comparison, fine silt plus clay, FSi+Cl, and fine sand, FSa) of an agricultural soil, unamended or amended with biochar, municipal solid waste compost, and a combination of both.<span> </span></p><p>FSa fractions showed the most significant Fe(II)-catalyzed ferrihydrite transformations with the consequent production of well-ordered Fe oxides irrespective of soil amendment, with the only exception being the compost-amended soils. In contrast, poorly crystalline ferrihydrite still constituted <em>ca. </em>45% of the FSi+Cl fractions of amended soils, confirming the that the higher SOM content in this fraction inhibits atom exchange between aqueous Fe(II) and the solid phase. Building on our knowledge of Fe(II)-catalyzed mineralogical changes in simple systems, our results evidenced that the mechanisms of abiotic Fe mineral transformations in bulk soils depend on Fe mineralogy, organic C content and quality, and organo-mineral associations that exist across particle-size SOM pools. Our results underline that in the fine fractions the increase in SOM due to organic amendments can contribute to limiting abiotic Fe(II)-catalyzed ferrihydrite transformation, while coarser particle-size fractions represent an understudied pool of SOM subjected to Fe mineral transformations.<span> </span></p>


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