scholarly journals Effects of Continuous Cropping of Dictyophora on Soil Physical and Chemical Properties, Microbial Biomass and Enzyme Activity

2021 ◽  
Vol 8 (7) ◽  
pp. 214-220
Author(s):  
Long Tong ◽  
◽  
Hongyan Li ◽  
Xiaoming Liu ◽  
Bin Li ◽  
...  

The continuous obstacle of Dictyophora indusiata has become the one of the main factors affecting the healthy development of D. indusiata industry. In order to study the effects of continuous cropping of D. indusiata on the soil environment, four treatments were used in this study: no planted (CK), planted for 1 years (1Y), continuous cropping for 2 years (2Y) and continuous cropping for 3 years (3Y), to determined of the yield of D. indusiata, soil physical and chemical properties, microbial content and enzyme activity. The results showed that the yield and soil pH value decreased with the increase of continuous cropping years, and the contents of organic matter, total nitrogen, total phosphorus and total potassium, C/N and C/P also increased with the increase of continuous cropping years. Soil availability decreased with the increase of continuous cropping years, the content of alkaline nitrogen, available phosphorus and available potassium decreased by 12.25%, 28.91% and 24.86% at 3Y compared with 1Y, respectively. The biomass of bacteria, actinomycetes and fungi and the total amount of microorganism in soil increased at 1Y compared with CK, but with the increase of continuous cropping years, the biomass of bacteria and actinomycetes and the total amount of microorganism decreased significantly, while the biomass of fungi increased significantly; the continuous cropping of D. indusiata also decreased the value of bacteria/fungi in soil. The enzyme activities of the soil were higher than those of the unplanted plots, however, the activities of urease, catalase, peroxidase, sucrase, phosphatase and protease decreased with the increase of continuous cropping years. In a word, with the increase of continuous cropping, the acidity of rhizosphere soil increased, the availability of soil nutrients and the activity of soil enzymes decreased, the biomass of soil microorganisms, bacteria and actinomycetes decreased. However, the increase of fungal biomass led to the decline of soil texture.

2012 ◽  
Vol 3 (2) ◽  
pp. 180-183
Author(s):  
Marcelo Ferrarezi de Andrade ◽  
Renato de Toledo Leonardo ◽  
Edson Alves de Campos ◽  
Milton Carlos Kuga ◽  
Marco Antonio Hungaro Duarte ◽  
...  

ABSTRACT Objective This study evaluated the flow, pH and calcium release of MTA Fillapex (G1) or Fillapex plus 10% in weight of calcium hydroxide powder (G2), compared to AH Plus (G3) and Sealapex (G4). Materials and methods The flow test was performed according to ISO 6876:2001 requirements. The sealers were placed into plastic tubes and immersed in deionized water. After 24 hours, 7, 14 and 28 days, the water of each tube was removed and tested to evaluate the pH values and the level of released calcium. Calcium release values were analyzed statistically by Kruskal Wallis and Dunn tests and pH values analyzed by ANOVA and Tukey tests (α = 5%). Results G1 presented higher flow among all sealers. The addition of 10% calcium hydroxide into MTA Fillapex reduced the flow (p < 0.05) but, in a level, that is lower than the one recommended for ISO norms. G2 and G4 presented pH values and calcium release higher than G3 (p < 0.05) in all periods. G1 presented pH value higher than G3 (p < 0.05), except in 7 days period (p > 0.05). G4 presented higher pH values than G1 and G2, but the calcium release was similar for all periods (p > 0.05). G3 presented lower calcium release among all groups (p < 0.05). Conclusion The addition of 10% calcium hydroxide in MTA Fillapex caused reduction in flow and no negative interference in pH and/or calcium release. However, the obtained flow is different from ISO requirements. Clinical relevance MTA Fillapex presents levels of flow above the ISO norms. The addition of calcium hydroxide is a suggestion for solving this problem, but the impact of these procedures should be carefully evaluated. How to cite this article Keine KC, Guiotti FA, Leonardo RT, Kuga MC, Duarte MAH, de Campos EA, de Andrade MF. Influence of the Addition of Calcium Hydroxide Powder on Some Physical and Chemical Properties of the Sealer MTA Fillapex. World J Dent 2012;3(2):180-183.


2019 ◽  
Vol 35 (4) ◽  
Author(s):  
Willian Barros Nascimento ◽  
Milton César Costa Campos ◽  
Bruno Campos Mantovanelli ◽  
Luís Antônio Coutrim dos Santos ◽  
José Mauricio Cunha ◽  
...  

The Amazon region has a great diversity of landscapes such as forests galleries, natural fields (“Cerrados Amazônicos”), dense forest, these environments made possible the formation of a broad class of soils over time. The aim of this study was to evaluate the physical and chemical properties of soils in different physiographic environments in southern Amazonas, Brazil. Three areas of representative physiographies were selected, all of them in natural conditions: natural field / forest and floodplain / dry land transitions, and corrugated relief areas. Soil samples were collected in layers of 0.0 to 0.20 and 0.80-1.0 m. From the samples collected the following physical analyzes were performed: particle size, bulk density, particle density, total porosity and saturated hydraulic conductivity; and chemical: exchangeable calcium, magnesium, aluminum and potassium available, phosphorus, potential acidity, pH and organic carbon. Based on the results of chemical analysis were calculated the sum of bases and base saturation. The results were submitted to multivariate statistics analysis, at the discretion of the principal component analysis (PCA). From the results it is clear that different physiographic environments studied influence the formation of different soil classes, featuring the diversity of Amazonian soils. The PCA allowed the distinction and formation of different similarity groups, thus enabling to relate the physical and chemical properties with the physiographic formation in which they are inserted.


2016 ◽  
Vol 841 ◽  
pp. 90-97 ◽  
Author(s):  
Antoni ◽  
Stephen Wibiatma Wijaya ◽  
Djwantoro Hardjito

Fly ash is a waste from coal burning, that are generated with fluctuation both in its physical and chemical characteristics. This characteristics of fly ash when used in the making of geopolymer concrete will greatly affect the final products obtained. The pH value measured in fly ash, according previous research, can influence the setting time of geopolymer and fly ash with high pH values can cause flash-setting in the concrete. Understanding more clearly about the factors that affect the setting time of fly ash based geopolymer is important for further progress and development of the material. It was found that factors that influence the setting time of geopolymer was not only from the physical and chemical properties of the fly ash itself. Other factors such as composition and mix design, manufacturing process and environmental conditions can also affect its setting time. The experimental results showed that fly ash particle size, CaO and MgO content, in addition to ratio of sodium silicate and sodium hydroxide in the alkali solution, molarity of NaOH, initial temperature of the mixture, curing temperature, and mix volume could potentially influence the setting time of the geopolymer mixture.


Author(s):  
Esther Abosede Ewetola ◽  
Folasade Mary Owoade ◽  
Olayinka Olakunle Olatunji

The assessment of degradation status of soils in selected areas of Ogbomoso, Oyo state wascarried out. The soil physical and chemical properties were evaluated using mini pits and surface sampling. The laboratory results obtained were compared with the standard indicators and criteria for land degradation assessment according to FAO, 1979. The results revealed that most of the cultivated parts of the study sites were very highly degraded compared to the soil under vegetative fallow which were moderately degraded. The textural class of the soil ranged from loamy sand to sandy loam. Saturated hydraulic conductivity ranged from 1.54 to 3.4 cm hr-1 corresponding low to moderate permeability. Bulk density ranged from 1.53 to 1.60 g cm-3. Organic matter was very low in all the study sites. Available phosphorus was low in all the locations. Total nitrogen was predominantly low in most of the cultivated and fallow soils. Exchangeable Sodium Percentage (ESP) of the sites depicted that most of the soils were slightly sodic. Summarily, the soil physical and chemical properties status when compared with the FAO standard show that the area either cultivated or fallow is under degradation. In order to optimize crop production in these areas, there may be need to introduce soil conservation strategies. The practice may include use of crop residues, green manure or poultry manure to boost soil fertility. Also regular monitoring of the fertility status of the soils is required.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ning Xu ◽  
Xue-Liang Peng ◽  
Hao-Ru Li ◽  
Jia-Xuan Liu ◽  
Ji-Si-Yu Cheng ◽  
...  

Collagen is a kind of biocompatible protein material, which is widely used in medical tissue engineering, drug delivery, cosmetics, food and other fields. Because of its wide source, low extraction cost and good physical and chemical properties, it has attracted the attention of many researchers in recent years. However, the application of collagen derived from terrestrial organisms is limited due to the existence of diseases, religious beliefs and other problems. Therefore, exploring a wider range of sources of collagen has become one of the main topics for researchers. Marine-derived collagen (MDC) stands out because it comes from a variety of sources and avoids issues such as religion. On the one hand, this paper summarized the sources, extraction methods and characteristics of MDC, and on the other hand, it summarized the application of MDC in the above fields. And on the basis of the review, we found that MDC can not only be extracted from marine organisms, but also from the wastes of some marine organisms, such as fish scales. This makes further use of seafood resources and increases the application prospect of MDC.


2021 ◽  
Vol 251 ◽  
pp. 02044
Author(s):  
Zhengwei Xie ◽  
Qianqian Ma ◽  
Wanyun Peng ◽  
Zhide Wang ◽  
Peng Wu ◽  
...  

Continuous cropping obstacle is a big problem of Strawberry planting. Continuous cropping obstacle leads to the accumulation of phenolic acids, imbalance of soil microorganism, deterioration of physical and chemical properties, resulting in sharp decline in Strawberry yield and quality. At present, the prevention and cure of continuous cropping obstacle of Strawberry is an urgent problem to be solved. The pathogen does not produce drug resistance, is safe to fresh fruit and does not pollute the environment.


Agro-Science ◽  
2021 ◽  
Vol 20 (2) ◽  
pp. 49-56
Author(s):  
A.O. Onunwa ◽  
C.J. Nwaiwu ◽  
J.E. Nwankwor ◽  
C.E. Emeh ◽  
C.O. Madueke ◽  
...  

Effects of four organic amendments on some soil physical and chemical properties were investigated in Awka, Anambra State in southeastern Nigeria. Over the years, use of synthetic materials in crop production has been a common practice globally. The attendant detrimental effects of the chemicals used in the formulation of these synthetics on animal and human health as well as the environment has made researchers to look out for a better agronomic practice that would not only improve productivity but at the same time sustain a healthy environment. Sole maize, sole cowpea and maize-cowpea intercrop (study area conventional practices) were planted using four soil organic amendments viz: cassava peel (CP), poultry manure (PM), pig waste (PW) and rice husk (RH) at the rate of 20 t ha–1 with the fifth as the control. The treatments were laid out in a 3 × 5 factorial in randomized complete block design and replicated four times. Data on the treatments’ effects on the selected soil physical properties (bulk density, total porosity, soil moisture) and chemical properties (soil pH, available phosphorus, cation exchange capacity (CEC), organic carbon, exchangeable bases and exchangeable acidity) were subjected to factorial analysis of variance using GenStat 2006 Edition. Results indicated that for sole maize, the amendments had significant effect onexchangeable Al3+and Na+; organic carbon, soil pH, available phosphorus and CEC but had no significant effect on Ca2+, H+, Mg2+ and K+ as compared to the control. For sole cowpea, compared to the plots with no amendment (control), all the chemical parameters analyzed differed significantly except organic carbon. Whereas, for maize-cowpea intercrop the treatments had no significant effect on Al3+, Na+, K+ and available phosphorus but differed significantly in exchangeable H+, Ca2+, Mg2+, organic carbon, soil pH, and CEC. There was a decrease in bulk density following the amendment. For sole maize, sole cowpea and maizecowpea intercrop; bulk density, total porosity and moisture content of the amended plots were significantly (p< 0.05) influenced. Organic amendments also significantly improved the growth and yield of maize and cowpea in both the sole and intercrop systems. Generally, poultry manure resulted in higher plant height,number of leaves and leaf area for maize; vine length, number of branches for cowpea as compared with other amendments. Hence, poultry manure was the most effective organic amendment in improving the soil physical and chemical properties as well as the growth and yield of cowpea and maize. Key words: Growth, maize-cowpea intercrop, soil physical and chemical properties, soil organic amendments


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