scholarly journals Comparison among Different Rewetting Strategies of Degraded Agricultural Peaty Soils: Short-Term Effects on Chemical Properties and Ecoenzymatic Activities

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1084
Author(s):  
Vittoria Giannini ◽  
Eleonora Peruzzi ◽  
Grazia Masciandaro ◽  
Serena Doni ◽  
Cristina Macci ◽  
...  

In 2013, a pilot experimental field of about 15 ha was set up within the basin of Lake Massaciuccoli (Tuscany, Italy) in order to compare different management strategies—a paludicultural system (PCS), a constructed wetland system (CWS), a nearly-natural wetland system (NWS)—for peatland restoration after almost a century of drainage-based agricultural use (CS). After five years, changes in peat soil quality were investigated from a chemical, biochemical, and ecoenzymatic perspective. The soil in CS was mainly characterized by oxidant conditions, higher content of overall microbial activity, low levels of easily available phosphorus for vegetation, and medium total carbon content ranging from 25.0% to 30.7%. In PCS, the levels of total carbon and the content of bioavailable P were higher, while the oxidant conditions were lower compared to the other systems. As expected, the soils in CWS and NWS were characterized by the most reduced conditions and by the highest levels of arylsulphatase activity. It was noteworthy that soils in the NWS systems were characterized by the highest level of nonavailable P. Outputs from ecoenzymatic activity confirmed the physico-chemical and biochemical results.

1997 ◽  
Vol 500 ◽  
Author(s):  
M. L. Pereira Da Silva ◽  
A. Romanelli Cardoso ◽  
J. J. Santiago-Aviles

ABSTRACTThis work presents the analysis performed on a SiO2 film deposited from organometallic precursors with the aim of correlating their physico-chemical properties including electrical characteristics with processing variables. The characterization tools used in this study included SEM for film homogeneity; SIMS for the determination of total carbon content; FT-MS and Raman scattering spectroscopy for surface characterization. GC-MS was used to understand the electrochemical reactions taking place while performing I-V characteristics measurements.The use of these multiple characterization techniques pointed out to deposited films with reasonable deposition characteristics but poor electrical ones. Phase segregated heterogeneity's rich in carbonatious residues influenced the degradation of the electrical characteristics.


Author(s):  
Shushank Sharma

The oral route is the most convenient route of administration for various drugs. It is viewed as the most convenient, most secure, and economical route for patients. Fast disintegrating tablets are popular these days as they disintegrate in the mouth within a few seconds without the use of water. The burdens of regularly used medications in pediatric and geriatric patients have been overwhelmed by quick-dissolving tablets. Natural superdisintegrants have been used for fast-dissolving tablets because they are biodegradable, chemically inert, non-harmful, more affordable, and generally accessible. Natural polymer improves the properties of the tablet as it is commonly used as diluents and binders. Natural super disintegrants decrease the release time and give healthful results to the patients. Most polymers are obtained from nature, they are cost-effective, non-toxic, and non-irritants. Disintegration is the most important step for releasing the drug from the tablet matrix to decrease the disintegration time. In this, drug and polymers come in contact with water, it swells, hydrate, and react chemically to release the drug in the mouth and gastrointestinal tract. Superdisintegrants are those substances that encourage the quick breaking down with a lesser amount contrasted with disintegrants. The quick disintegrants tablets are set up by utilizing suitable polymers which rely on the Physico-chemical properties of drugs and excipients, for example, drug and polymer compatibility, hardness and thickness of tablet, nature of drug and excipients, PH of drug and release parameters of drug formulation. Superdisintegrants are the vehicles added to tablet formulation to advance the breaking of tablets and capsules into small microparticles in aqueous media resulting in to increase in the surface area and promote quick drug release. The disintegrants have a significant capacity to oppose the efficacy of tablet binders and compression forces to form the tablet. Commonly there are three methods to incorporate disintegrants into the tablet: A. Inner addition, B. External expansion, C. Internal, and external addition. Most of the regularly based tablets are those expected to be swallow, disintegrate and release medicaments in the gastrointestinal tract but over a while tablets are manufactured to deliver medicaments in the mouth and gastrointestinal tract within few seconds of swallowing. It has been demonstrated that characteristic polymers are more effective than synthetic polymers. Some research is going to develop safe and effective medication with super disintegrating agents that can be dissolved rapidly to treat the disease.


2014 ◽  
Vol 9 ◽  
pp. 27-39 ◽  
Author(s):  
Ram K. Shrestha

A study was carried out to compare the fertility of soils under improved soil  management practice with that of prevailing conventional practice and to assess the farmers’ perception on the improved practice in the upland   farming system. The study was carried out in Nasikasthan Sanga of Kavrepalanchok district of Nepal. Soil samples were collected from fields under improved conventional practice. Samples were taken at 0-15 and 15-30 cm depths and were analyzed for various physico-chemical properties to  compare the fertility status of the soils under both the practices. Altogether 68 farmers were interviewed to have information on farming practices and information pertinent to improved soil management practice being adopted by them. Results from soil physico-chemical analysis showed higher fertility of soils under improved practice in terms of more favorable pH level,  contents of exchangeable bases, available phosphorus and soil organic matter compared to prevailing conventional soil management practice. Moreover, majority of the farmers believed that soil fertility and physical condition of their upland soils had improved and that the productivity of major upland  crops had also increased after the adoption of improved soil management practice. Improved practice could play an important role in the sustainable management of upland soils in the mid hills of Nepal. It is however, desirable to conduct long-term research to further ascertain the effect of the practice on soil fertility of different soil types and land uses.Nepal Agric. Res. J. Vol. 9, 2009, pp. 27-39DOI: http://dx.doi.org/10.3126/narj.v9i0.11639 


Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 279 ◽  
Author(s):  
Thomas E. Marler

Research Highlights: Established stands of Leucaena leucocephala (Lam.) de Wit, Spathodea campanulata P. Beauv., and Vitex parviflora Juss. modified soils in Guam’s limestone forests, reducing storage pools of carbon, nitrogen, and phosphorus. Background and Objectives: Invasive plants may engineer negative changes in ecosystem properties. This study was conducted to determine changes in soil chemistry following infestations of three problematic tree species on Guam. Materials and Methods: Minerals, metals, and mineralization dynamics were measured in invaded sites and paired sites with biodiverse native tree cover. Results: Most soil properties were significantly changed by long-term infestations of the invasive tree species. The soils within invaded sites exhibited total carbon, total nitrogen, and available phosphorus that were less than native sites. In contrast, the carbon/nitrogen ratio increased for every species-site combination. The other chemical properties were idiosyncratic among the sites and species. Conclusions: Mitigation and restoration activities that include the removal of these trees from project sites may require many years for the below-ground ecosystems to return to their native state. These three invasive trees decrease the ability of Guam soils to sequester recalcitrant forms of carbon, nitrogen, and phosphorus.


Author(s):  
Gintaras JARAŠIŪNAS ◽  
Irena KINDERIENĖ

The objective of this study was to evaluate the impact of different land use systems on soil erosion rates, surface evolution processes and physico-chemical properties on a moraine hilly topography in Lithuania. The soil of the experimental site is Bathihypogleyi – Eutric Albeluvisols (abe–gld–w) whose texture is a sandy loam. After a 27-year use of different land conservation systems, three critical slope segments (slightly eroded, active erosion and accumulation) were formed. Soil physical properties of the soil texture and particle sizes distribution were examined. Chemical properties analysed for were soil ph, available phosphorus (P) and potassium (K), soil organic carbon (SOC) and total nitrogen (N). We estimated the variation in thickness of the soil Ap horizon and soil physico-chemical properties prone to a sustained erosion process. During the study period (2010–2012) water erosion occurred under the grain– grass and grass–grain crop rotations, at rates of 1.38 and 0.11 m3 ha–1 yr–1, respectively. Soil exhumed due to erosion from elevated positions accumulated in the slope bottom. As a result, topographic transfiguration of hills and changes in soil properties occurred. However, the accumulation segments of slopes had significantly higher silt/clay ratios and SOC content. In the active erosion segments a lighter soil texture and lower soil ph were recorded. Only long-term grassland completely stopped soil erosion effects; therefore geomorphologic change and degradation of hills was estimated there as minimal.


2020 ◽  
Vol 21 (8) ◽  
Author(s):  
Dwi Astiani ◽  
TRI WIDIASTUTI ◽  
SITI LATIFAH ◽  
DARBIN SIMATUPANG

Abstract. Astiani D, Widiastuti T, Latifah S, Simatupang D. 2020. Soil characteristics and CO2 emissions of ex-burnt peatland in Kubu Raya District, West Kalimantan, Indonesia. Biodiversitas 21: 3691-3698. West Kalimantan, Indonesia has a large extent of tropical peatland with total ​​1.74 million ha with only 44.5% of such areas remaining as peat forest, while the rests have been converted into plantations, agricultural lands, and shrubs. The conversion of peat forest often uses fires to clear the vegetation and is followed by building canal to drain the water. The lack of vegetation combined with drought soil trigger uncontrolled escaped fire, especially in the dry season or El-Nino events, which is likely to affect soil characteristics and emit carbon dioxide. The purpose of this study is to examine the changes in soil characteristics both physical and chemical properties and to investigate CO2 emissions from peat soil post-fire. As a comparison, similar parameters were also assessed in non-burnt sites. The results showed significant differences in some peat soil characters both physically and chemically between ex-burnt and non-burnt peatland. The ex-burnt site had higher pH, available phosphorus and C/N ratio than those in the non-burnt site. Conversely, the total nitrogen and carbon contents, and cation exchange capacity were lower which is likely due to leaching. Peat fires also impacted physical characteristics of the soil such as increasing soil bulk density, reducing soil water content, soil temperature, especially in wet conditions. Carbon dioxide emissions in the ex-burnt site were considered higher than non-burnt site. These results could be brought out as a part of baseline data in managing ex-burnt peatlands to maintain a balance between carbon output and input and efforts on preventing peatland fires from becoming continuous carbon sources.


2021 ◽  
Vol 9 (1) ◽  
pp. 17-26
Author(s):  
NTANGMO TSAFACK Honorine ◽  

Soil fertility indices are well documented as they are directly related to land use and productivity. However, the effect of continuous intensive cultivation on the evolution of soil fertility is still poorly documented. The aim of this study was thus to assess the effect of continuous intensive cultivation on the chemical and microbiological properties of Oxic Dystrandept soils in the Western Highlands of Cameroon. Composite soil samples were taken between 0-15 cm depths on farmlands that have been subjected to continuous intensive cultivation for one, five and ten years meanwhile samples from plots that have never been cultivated served as control. The main results revealed that the ammonium contents dropped abruptly (86%-wt) from the first year of cultivation. The organic carbon (OC) content decreased from 1.81 ± 0.14 %-dm (in control) to 1.69 ± 0.09 % after one year, 1.66 ± 0.10 % after 5 years and 1.58 ± 0.07 % after 10 years. Compared to the control, available phosphorus (P) showed a 13 %-wt drop after one year, 46 % after 5 years and 85 % after 10 years. Dehydrogenase activity showed a 42 % decrease after one year, 50 % after five years and 73 % after 10 years. The other parameters were not significantly different (P<0.05) amongst treatments. Decline of soil productivity was undoubtedly related to the decrease of OC, P, microbial activity and ammonium with continuous intensive cultivation. Thus, management strategies for improved crop production should include selection suitable cropping systems and chemical methods. Keywords: Continuous intensive cultivation, enzymatic activities, soil chemical properties, Oxic Dystrandept, Cameroon western highland


2020 ◽  
Vol 41 (6) ◽  
pp. 1665-1675
Author(s):  
R. Bhatt ◽  
◽  
Sanjay Swami ◽  

Aim: To delineates micro and macro nutrients along with physico-chemical properties of Ratte-Khera farm of Punjab Agricultural University (PAU), Ludhiana, Punjab, India for effective use of nutrients. Methodology: Thirty two soil samples were collected during 2019 from eight different location using GPS from different soils depths viz.? 0-15,15-30, 30-60 and 60-90 cm in the problematic water logged soils of Ratte-khera farm. Further, GPS maps were also prepared pertaining to different depths for the judicious use of fertilizers in the region.? Parker nutrient index was also evaluated for different nutrients for the region. Results: Around 87.5% of the samples had normal pH (6.5 -8.7) and 12.5% soils were with pH on higher side with higher range of EC, lower range of SOC, higher and potassium. About 87.5 % samples were in higher available-phosphorus. Further, lower and higher range of DTPA zinc and copper observed in samples while 25 and 37.5% recorded with lower range of DTPA iron (Fe) and manganese (Mn). Correlation analysis revealed? availability of Fe is positively associated with Mn, P, Cu and Zn in the soil. Interpretation: Soils of Ratte-Khera farm reported to be saline (white alkali soils) with normal range of pH (no need to add any gypsum or lime). Final recommendation is to apply 25% higher dose of nitrogenous (N) and phosphatic (P) fertilizers with no need for potassic fertilizers. Further, micro-nutrients should be applied as and when symptoms observed on the field crops.


Author(s):  
Syahminar Syahminar ◽  
Erwin Masrul Harahap ◽  
Abdul Rauf ◽  
Ali Jamil

The aim of this study was to obtain the best combination of types and doses of ameliorant materials: dolomite, rock phosphate, and mineral soil to improve the chemical properties of soil which was incubated for one year in peat media in polybag. The research was conducted in May 2015 - April 2016 in the experimental garden in the village of Sijambi, Tanjungbalai, North Sumatra. Elevation 3 m above sea level, with the C2 (Oldeman) climate type. The experiment was compiled using a Randomized Block Design, with 3 treatments of ameliorant material. The three ameliorant materials were tested for 3 doses. The addition of dolomite treatment: A1=0.45 kg polybag-1; A2=0.90 kg polybag-1; A3=1.35 kg polybag-1. The addition of rock phosphate treatment: A4=0.45 kg polybag-1; A5=0.90 kg polybag-1; A6=1.35 kg of polybag-1. The addition of mineral soil treatment: A7=0.45 kg polybag-1; A8=0.90 kg polybag-1; and A9=1.35 kg polybag-1.The results shown that the highest dose of dolomite (1.35 kg polybag-1) improved soil chemical properties, including soil pH and alkali cations (K, Ca and Mg) on incubated peat soil. Addition of rock phosphate with the highest dose of 1.35 kg polybag-1 (A6) increases available phosphorus and soil CEC. Addition of mineral soil dose of 0.90 kg polybag-1 (A8) increases soil CEC. In the analysis of total soil nitrogen, the highest increase was obtained by adding dolomite dose of 0.45 kg.polibag-1 (A1).


Author(s):  
Shushank Sharma ◽  
Sikha Chauhan

The oral route is the most convenient route of administration for various drugs. It is viewed as the most convenient, most secure, and economical route for patients. Fast disintegrating tablets are popular these days as they disintegrate in the mouth within a few seconds without the use of water. The burdens of regularly used medications in pediatric and geriatric patients have been overwhelmed by quick-dissolving tablets. Natural superdisintegrants have been used for fast-dissolving tablets because they are biodegradable, chemically inert, non-harmful, more affordable, and generally accessible. Natural polymer improves the properties of the tablet as it is commonly used as diluents and binders. Natural super disintegrants decrease the release time and give healthful results to the patients. Most polymers are obtained from nature, they are cost-effective, non-toxic, and non-irritants. Disintegration is the most important step for releasing the drug from the tablet matrix to decrease the disintegration time. In this, drug and polymers come in contact with water, it swells, hydrate, and react chemically to release the drug in the mouth and gastrointestinal tract. Superdisintegrants are those substances that encourage the quick breaking down with a lesser amount contrasted with disintegrants. The quick disintegrants tablets are set up by utilizing suitable polymers which rely on the Physico-Chemical properties of drugs and excipients, for example, drug and polymer compatibility, hardness and thickness of tablet, nature of drug and excipients, PH of drug and release parameters of drug formulation. Superdisintegrants are the vehicles added to tablet formulation to advance the breaking of tablets and capsules into small microparticles in aqueous media resulting in to increase in the surface area and promote quick drug release. The disintegrants have a significant capacity to oppose the efficacy of tablet binders and compression forces to form the tablet. Commonly there are three methods to incorporate disintegrants into the tablet: A. Inner addition, B. External expansion, C. Internal, and external addition. Most of the regularly based tablets are those expected to be swallow, disintegrate and release medicaments in the gastrointestinal tract but over a while tablets are manufactured to deliver medicaments in the mouth and gastrointestinal tract within few seconds of swallowing. It has been demonstrated that characteristic polymers are more effective than synthetic polymers. Some research is going to develop safe and effective medication with super disintegrating agents that can be dissolved rapidly to treat the disease.


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