Characterisation of production of organic rich topsoil from sludge

2000 ◽  
Vol 42 (9) ◽  
pp. 195-201 ◽  
Author(s):  
P. Andreasen ◽  
P. B. Mortensen ◽  
A. Stubsgaard ◽  
B. Langdahl

The stabilisation of a sludge-mineral soil mixture and a method to evaluate the state of stabilisation were investigated. The organic matter and nitrogen content are reduced up to 50% during a stabilisation process of three months under Danish climatic conditions. The stabilisation was shown to be an aerobic process limited by oxygen transport within the mixture. The degree of stabilisation was evaluated by oxygen consumption in a water suspension and the results showed that a stable product was achieved when oxygen consumption was stable and in the level of natural occurring aerobic soils (0.1 mgO2/(g DS*hr). The study thereby demonstrates that a stability of a growth media can be controlled by the oxygen consumption method tested.

1998 ◽  
Vol 78 (3) ◽  
pp. 477-479 ◽  
Author(s):  
C. J. Westman ◽  
S. Jauhiainen

Forest soil pH in southwest Finland was measured with identical sampling and analysing methods in 1970 and 1989. The acidity of the organic humus layer increased significantly as pH values measured on water and on salt suspensions decreased between the two sampling dates. For the mineral soil layers, no unambiguous trend was found. pH values measured on salt suspension tended to be unchanged or lower, while pH on water suspension in some soil layers were even higher in 1989 than in 1970. Key words: pH, repeated sampling


2012 ◽  
Vol 9 (12) ◽  
pp. 5181-5197 ◽  
Author(s):  
C. Moni ◽  
D. Derrien ◽  
P.-J. Hatton ◽  
B. Zeller ◽  
M. Kleber

Abstract. Physical fractionation is a widely used methodology to study soil organic matter (SOM) dynamics, but concerns have been raised that the available fractionation methods do not well describe functional SOM pools. In this study we explore whether physical fractionation techniques isolate soil compartments in a meaningful and functionally relevant way for the investigation of litter-derived nitrogen dynamics at the decadal timescale. We do so by performing aggregate density fractionation (ADF) and particle size-density fractionation (PSDF) on mineral soil samples from two European beech forests a decade after application of 15N labelled litter. Both density and size-based fractionation methods suggested that litter-derived nitrogen became increasingly associated with the mineral phase as decomposition progressed, within aggregates and onto mineral surfaces. However, scientists investigating specific aspects of litter-derived nitrogen dynamics are pointed towards ADF when adsorption and aggregation processes are of interest, whereas PSDF is the superior tool to research the fate of particulate organic matter (POM). Some methodological caveats were observed mainly for the PSDF procedure, the most important one being that fine fractions isolated after sonication can not be linked to any defined decomposition pathway or protective mechanism. This also implies that historical assumptions about the "adsorbed" state of carbon associated with fine fractions need to be re-evaluated. Finally, this work demonstrates that establishing a comprehensive picture of whole soil OM dynamics requires a combination of both methodologies and we offer a suggestion for an efficient combination of the density and size-based approaches.


Radiocarbon ◽  
2016 ◽  
Vol 59 (2) ◽  
pp. 489-503 ◽  
Author(s):  
E Zazovskaya ◽  
N Mergelov ◽  
V Shishkov ◽  
A Dolgikh ◽  
V Miamin ◽  
...  

AbstractThis article discusses radiocarbon dating results for soils and soil-like systems in the East Antarctic oases, including Schirmacher, Thala Hills, and Larsemann Hills. The organic matter of endolithic and hypolithic systems, soils of wind shelters, and soils under moss-algae vegetation were dated along with micro- and macroprofiles. Organic matter pools formed under extreme climatic conditions and originated not from vascular plants but from cryptogamic organisms, and photoautotrophic microbes have been identified within the oases of the East Antarctica. The organic matter of the most of East Antarctic soils is young and cannot reach a steady state because of the high dynamism in the soil cover due to active erosion. The oldest soil organic matter in East Antarctica was found in the soils formed in wind shelters and endolithic soil-like systems under the protection of consolidated rock surfaces. According to our data, the maximal duration for the formation of organic matter profiles within the oases of East Antarctica is ~500 yr, which is similar to the age determined for High Arctic soils in Eurasia. The absence of older soils, comparable with the Holocene deglaciation, can be due to the extreme conditions resulting in occasional catastrophic events that destroyed the soil organic horizons.


2013 ◽  
Vol 10 (3) ◽  
pp. 1365-1377 ◽  
Author(s):  
M. O. Rappe-George ◽  
A. I. Gärdenäs ◽  
D. B. Kleja

Abstract. Addition of mineral nitrogen (N) can alter the concentration and quality of dissolved organic matter (DOM) in forest soils. The aim of this study was to assess the effect of long-term mineral N addition on soil solution concentration of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in Stråsan experimental forest (Norway spruce) in central Sweden. N was added yearly at two levels of intensity and duration: the N1 treatment represented a lower intensity but a longer duration (43 yr) of N addition than the shorter N2 treatment (24 yr). N additions were terminated in the N2 treatment in 1991. The N treatments began in 1967 when the spruce stands were 9 yr old. Soil solution in the forest floor O, and soil mineral B, horizons were sampled during the growing seasons of 1995 and 2009. Tension and non-tension lysimeters were installed in the O horizon (n = 6), and tension lysimeters were installed in the underlying B horizon (n = 4): soil solution was sampled at two-week intervals. Although tree growth and O horizon carbon (C) and N stock increased in treatments N1 and N2, the concentration of DOC in O horizon leachates was similar in both N treatments and control. This suggests an inhibitory direct effect of N addition on O horizon DOC. Elevated DON and nitrate in O horizon leachates in the ongoing N1 treatment indicated a move towards N saturation. In B horizon leachates, the N1 treatment approximately doubled leachate concentrations of DOC and DON. DON returned to control levels, but DOC remained elevated in B horizon leachates in N2 plots nineteen years after termination of N addition. We propose three possible explanations for the increased DOC in mineral soil: (i) the result of decomposition of a larger amount of root litter, either directly producing DOC or (ii) indirectly via priming of old SOM, and/or (iii) a suppression of extracellular oxidative enzymes.


Author(s):  
Tracy Saptu ◽  
Nur Ashikin Psyquay Abdullah ◽  
Franklin Ragai Kundat ◽  
Aicher Joseph Toyat ◽  
Calson Gimang Endawie ◽  
...  

A study was conducted to determine the best agronomic practices for the cultivation of jerangau merah as a new medicinal crop. Jerangau merah is scientifically known as Boesenbergia stenophylla is a ginger plants that is highly endemic to the Borneo Highland. This understorey herb grows in cluster and under the heavy shades of forest canopies and perceived only the sunflecks that pass through the forest canopies. Jerangau Merah has been consumed by the locals for its medicinal values since decades ago. Generally, B. stenophylla is well known for its function as antidote for alcohol. Moreover, the B. stenophylla is also beneficial for rheumatic pains, remedies for stomach ache and toothache and as antiseptic wash as well. This herb is not propagate by the locals due to its sensitivity to sunlight and lack of agronomic information for B. stenophylla. Harvesting it from their natural habitat, however, seen the decline it its population size hence cultivation is essential. This paper aimed to determine the total nutrients, dry matter yield and phytochrome content of Bosenbergia stenophylla R.M. Smith under different light regimes. A study for determining suitable planting media for B. stenophylla was conducted at Universiti Putra Malaysia (UPM). The treatments are: i) (M1) with the ratio of 3:2:1 top soil: sand: organic matter, media ii) (M2) consists of soil mixture 3:2:1 placed in water-logged polyethylene bags and media iii) (M3) contained only leaf litters. The results showed that the herbs showed significantly higher number of shoots and leaves in the common soil mixture. But, better root development in media containing leaf litters. The study proceeded with field experiment at Ba’Kelalan to determine the effect of different shade levels and fertilizing regimes on growth. B. stenophylla was cultivated under two different levels of shade cloths: 70% and 90% level of shade and different fertilizing regimes (T1 as control, no fertilizer applied to the plants; T2, chicken dung; T3, NPKMg and T4, mixed of chicken dung and NPKMg). The study for determining the effects of different shade level and fertilizing regimes on seedling’s growth which conducted at Ba’Kelalan in factorial randomized completely blocked design (RCBD). The data collected for 9 weeks of planting which include nutrient content in soil, leaf, PAR and phytochrome content and growth parameters. Regarding the nutrient uptake, the results showed no interactions between fertilizing regimes and shade levels. There were no significant different in nutrient elements except for magnesium and potassium. Magnesium is essential for the formation of chlorophyll which ensure efficiency of photosynthesis when under higher light intensity. Among all the fertilizer treatment, it was showed that chicken dung amendment has higher nutrient uptake. Thus, it is recommended chicken dung should be added into the NPKMg for better nutrient uptake. Further study on suitable fertilizer rates apply to B. stenophylla should be taken into consideration. Moreover, plants cultivated under 70% have been higher and have higher dry matter yield than those plants cultivated under 90%. The result also revealed that there was significant different in chlorophyll content of B. stenophylla cultivated under 70% which treated either with chicken dung and NPKMG respectively. However, plants under 90% have higher chlorophyll content than those under 70%. Based on the results, plants under 70% shade was taller than those under 90% and there were significant difference in height among treatments under 70%.  It was observed plant treated with NPKMg was taller. This study showed that shade and fertilizers significantly affected the dry matter yield of B. stenophylla. Moreover, adding NPKMg to the treatments yields more dry matter content of jerangau merah. As for phytochrome content, there was no significant effect of fertilizer on phytochrome content. However, there was significant difference among the shade levels. 90% shade showed higher phytochrome content than those under 70%. In overall, both shade and fertilizer is important in cultivation of Jerangau Merah. 70% shade was observed to have significant effects on growth of jerangau merah and also more economical compared to 90%. Moreover, combination of organic matter and NPKMg also promote the growth of jerangau merah enhance the nutrient uptake efficiency of jerangau merah. However, further investigation of suitable fertilizer and application rate are required to determine suitable fertilizer for jerangau merah and application rate for optimum growth of jerangau merah.


Author(s):  
Dennis Knight ◽  
Daniel Tinker

In forest ecosystems, the decomposition of coarse woody debris, woody roots, twigs, leaves and micro-organisms is a primary source of mineral soil organic matter. Primary productivity, the accumulation of nutrients, and other important ecosystem processes are largely dependent on the mineral soil organic matter that has developed during hundreds or thousands of years. Large quantities of coarse woody debris are typically produced following natural disturbances such as fires, pest/pathogen outbreaks, and windstorms, and make a significant contribution to the formation of soil organic matter (SOM). In contrast, timber harvesting often removes much of the coarse woody debris (CWD), which could result in a decrease in the quantity and a change in the quality of mineral soil organic matter.


2011 ◽  
Vol 8 (1) ◽  
pp. 549-592 ◽  
Author(s):  
L. Pastor ◽  
C. Cathalot ◽  
B. Deflandre ◽  
E. Viollier ◽  
K. Soetaert ◽  
...  

Abstract. In-situ oxygen microprofiles, sediment organic carbon content and pore-water concentrations of nitrate, ammonium, iron, manganese and sulfides obtained in sediments from the Rhône River prodelta and its adjacent continental shelf were used to constrain a numerical diagenetic model. Results showed that (1) organic matter from the Rhône River is composed of a fraction of fresh material associated to high first-order degradation rate constants (11–33 yr−1), (2) burial efficiency (burial/input ratio) in the Rhône prodelta (within 3 km of the river outlet) can be up to 80%, and decreases to ~20% on the adjacent continental shelf 10–15 km further offshore (3) there is a large contribution of anoxic processes to total mineralization in sediments near the river mouth, certainly due to large inputs of fresh organic material combined with high sedimentation rates, (4) diagenetic by-products originally produced during anoxic organic matter mineralization are almost entirely precipitated (>97%) and buried in the sediment, which leads to (5) a low contribution of the re-oxidation of reduced products to total oxygen consumption. Consequently, total carbon mineralization rates as based on oxygen consumption rates and using Redfield stoichiometry can be largely underestimated in such River Ocean dominated Margins (RiOMar) environments.


2019 ◽  
Author(s):  
Kelath Murali Manoj

Cyanide is conventionally perceived as a binder of heme-Fe centers, disrupting oxygen transport by blood hemoglobin and mitochondrial cytochrome oxidase function. This explanation of toxicity would require millimolar (g/Kg dosage) concentration of cyanide, whereas it is lethal even at micromolar (mg/Kg dosage) ranges. It is long known that oxygen consumption by cells leads to the production of diffusible reactive oxygen species (DROS). Recently, DROS mediated catalytic/metabolic roles were proposed as a physiological source of heat and phosphorylation of ADP within mitochondria. In this purview, it is hypothesized herein that cyanide uses the catalytic DROS via futile cycles, stopping ATP-synthesis and thus killing cells. A quantitative mechanistic perspective delineating the old and new explanations is provided herein. Further, experimental modalities and predictable outcomes are detailed to test the new hypothesis.


Sign in / Sign up

Export Citation Format

Share Document