scholarly journals Effects of Graphene on Larix olgensis Seedlings and Soil Properties of Haplic Cambisols in Northeast China

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 258 ◽  
Author(s):  
Jinfeng Song ◽  
Kai Cao ◽  
Chengwei Duan ◽  
Na Luo ◽  
Xiaoyang Cui

We investigated the impacts of graphene application at different concentrations on the growth and physiological characteristics of Changbai larch (Larix olgensis A. Henry) seedlings and the chemical properties and enzyme activities of Haplic Cambisols under these seedlings. The aim is to evaluate the environmental effects of graphene on the afforestation species and the zonal forest soils of Northeast China. Seedlings receiving 0 (CK), 25, 50, 100, 250, or 500 mg L−1 graphene were incubated for 30, 40, or 50 days. Low concentrations (25–50 mg L−1) of graphene increased the dry masses of root, stem, and leaf; however, high concentrations (100–500 mg L−1) inhibited them. Compared with those under 0 mg L−1 graphene, the root length, surface area, volume, and average diameter all increased during the early stages of incubation (i.e., 30 and 40 days) under low concentration of graphene (<50 or 100 mg L−1) and decreased at higher graphene concentration (>100 mg L−1); at 50 days, they were significantly inhibited. At 30 days, graphene decreased superoxide dismutase (SOD) and peroxidase (POD) activities, as well as pigment, soluble protein, and proline contents, and the decline increased with increasing graphene concentration; at 40 and 50 days, the above parameters increased initially and then decreased, reaching a maximum at 50 mg L−1. The changes in relative conductivity and malondialdehyde (MDA), superoxide anion and hydrogen peroxide contents were the opposite of those in the physiological indexes mentioned above. Therefore, graphene caused different degrees of oxidative stress in L. olgensis seedlings. At 30 days, graphene generally increased the organic matter, hydrolytic nitrogen, and available phosphorus and potassium contents of Haplic Cambisols, but these parameters decreased at 40 and 50 days. Graphene generally decreased acid phosphatase, urease, dehydrogenase, and catalase activities. Therefore, when graphene reaches a certain content level in this soil, it may also affect nitrogen and phosphorus cycling.

Author(s):  
Vítězslav Vlček ◽  
Miroslav Pohanka

Soil samples (n = 11) were collected in the chernozem areas of the Czech Republic (the Central Europe) from the topsoil and used as representative samples. All sampling areas have been used for agricultural purposes (arable soil) and they were selected as typical representatives of agricultural soil. These samples represented the soil with same genesis (to reduction differencies between soil types) but with different soil properties (physical and chemical). Complete chemical and physical analyses were made for confirmation of copper adsorption on solid phase: we analysed the particle size distribution, content of oxidizable carbon (Cox), the cation exchange capacity (CEC), supply of exchange calcium, magnesium, sodium, phosphorus and potassium, soil reaction and the total supply of Fe, Al, Mn, Ca, Mg, K, P and N. The strongest simple correlation between analysed soil properties and copper concentration had content of available magnesium (r = 0.44) and available phosphorus (r = −0.51). In the case of multiple correlations (i. e. collective influence of multiple soil properties) had the strongest influence combination of clay, soil reaction, total content of phosphorus, available magnesium and available phosphorus. The main influence of phosphorus and magnesium is evident. We suppose that copper and phosphorus enter into specific complex. Influence of these five soil properties can explain 92.7 % (r = 0.927) changes in the content of copper changes in the experiment.


2021 ◽  
Author(s):  
Wenchun He ◽  
Yang Wang ◽  
Xiaochen Wen ◽  
Yu Wang ◽  
Baoru Xiao ◽  
...  

Abstract The growth of fine roots of trees is affected by environmental changes and biological factors. At present, there have been many researches on the physiological plasticity of fine roots caused by environmental changes, but there are still few studies on the influence of biological factors on fine roots. This paper focused on the contents of carbon (C), nitrogen (N), and phosphorus (P), and their ecological stoichiometric ratios in different root orders of Cupressus funebris fine roots in 11 mixed stands with Koelreuteria paniculate or Toona sinensis at different ratios, and the effects of soil physical and chemical properties on the root chemical properties. It aimed to provide new insights into the fine-root nutrient distribution pattern and the transformation or reconstruction of low-efficiency pure forests from the standpoint of forest types. The results showed that: soil pH, and the content of available nitrogen (SAN), available phosphorus (SAP) and available potassium (SAK) differed significantly in the tested mixed forest stands. No significant differences in carbon content of fine roots were observed in different mixed stands. The content of nitrogen and phosphorus in fine roots in mixed forests showed heterogeneity. Species mixing changed the C/N, C/P and N/P of the C. funebris compared the pure stands. The "T. sinensis + C. funebris" forest alleviated the limitation of the lack of phosphorus on fine roots of C. funebris on. The principal component analysis showed that mixed stands of "T. sinensis + C. funebris" had the highest comprehensive score at ratio of "3:1". Thus, our results recommended the adoption of T. sinensis, especially at 75%, to reconstruct the low-efficiency pure C. funebris forest.


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.


Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 757
Author(s):  
Vera Rajičić ◽  
Vera Popović ◽  
Vesna Perišić ◽  
Milan Biberdžić ◽  
Zoran Jovović ◽  
...  

The objectives of this study were to investigate: (1) the effects of fertilization, environment, and their interactions on the thousand grain weight (TGW), hectolitre weight (HW) and grain yield (GY) of winter triticale, and (2) the correlations between these traits in different environments. The invariable nitrogen (80 kg N ha−1), potassium (60 kg K2O ha−1) and two phosphorus (60 and 100 kg P2O5 ha−1) doses were used in Kragujevac location in central Serbia. Nitrogen was applied individually and in combination with two phosphorus rates and one rate of potassium fertilizer. Eight fertilization treatment controls and N80, P60, P100, N80P60K60, N80P100K60, N80P60 and N80P100 were examined during three growing seasons. The yield and quality of triticale significantly varied across years and treatments. The average yield of all treatments in the 2015 growing season was significantly greater than in the previous years (3.597 t ha−1). Combined usage of NPK fertilizer (80 kg N ha−1, 100 kg P2O5 ha−1 and 60 kg K2O ha−1) represented the excellent base for optimum supply of major nutrients, resulting in maximum GY (4.0 t ha−1). Negative and significant correlation was found between grain GY and TGW (−0.392*) in 2015, and positive highly significant correlation were in 2013 (0.648**) and 2014 (0.493**). The positive effect over complete application of fertilizer is the result of a lower pH value of the soil, as well as the low content of available phosphorus and potassium in Vertisol soil type. Optimizing fertilization for maximum profitability is of great importance in the future triticale production in Pannonian Environments.


2021 ◽  
Vol 11 ◽  
Author(s):  
Fangfang Cai ◽  
Peiyu Luo ◽  
Jinfeng Yang ◽  
Muhammad Irfan ◽  
Shiyu Zhang ◽  
...  

The objective of this study was to find out changes in ammonia oxidation microorganisms with respect to fertilizer as investigated by real-time polymerase chain reaction and high-throughput sequencing. The treatments included control (CK); chemical fertilizer nitrogen low (N) and high (N2); nitrogen and phosphorus (NP); nitrogen phosphorus and potassium (NPK) and organic manure fertilizer (M); MN; MN2; MNPK. The results showed that long-term fertilization influenced soil fertility and affected the abundance and community of ammonia-oxidizing microorganisms by changing the physical and chemical properties of the soil. The abundance and community structure of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) was influenced by soil organic carbon, total nitrogen, total soil phosphorus, available phosphorus, available potassium, and soil nitrate. Soil environmental factors affected the nitrification potential by affecting the structure of ammonia-oxidizing microorganisms; specific and rare AOA and AOB rather than the whole AOA or AOB community played dominant role in nitrification.


1991 ◽  
Vol 24 (9) ◽  
pp. 277-286 ◽  
Author(s):  
J. M. Russell ◽  
R. N. Cooper ◽  
S. B. Lindsey

Meat-processing wastewaters contain high concentrations of nitrogen, phosphorus and potassium (in this study 40-230 g m−3, 6-35 g m−3 and 20-130 g m−3 respectively), but only low concentrations of heavy metals and other toxic compounds. The nutrients can be recovered by agricultural or forestry irrigation schemes. Application of these wastes to land in excess of plant requirements results in elevated concentrations of organic nitrogen, nitrate, phosphorus, potassium and sodium in the plant material, with nitrate approaching levels toxic to ruminant animals. Excess phosphorus that is applied to the land is precipitated as metal phosphates, and excess nitrogen is partially denitrified, thereby reducing nitrate contamination of ground water. At an experimental pasture site, receiving nitrogen loadings of 1200 kg N ha−1 y−1, denitrification losses averaged about 4% of that applied. Denitrification losses at an experimental forestry site receiving 715 kg N ha−1 y−1 averaged about 27%. Similar losses were observed at a full-scale pasture and forestry irrigation site. Sodium concentrations in meat processing wastewaters could, on occasions, detrimentally affect soil structure and sodium concentrations should be closely monitored.


2016 ◽  
Vol 92 (03) ◽  
pp. 336-344 ◽  
Author(s):  
Nan Zeng ◽  
Huaxia Yao ◽  
Mei Zhou ◽  
Pengwu Zhao ◽  
Jeffrey P. Dech ◽  
...  

Tree mortality is a notable phenomenon in the forest-steppe ecotone of China. However, the association between mortality and factors such as a changing climate is uncertain. In the summer of 2014 tree mortality was investigated in 20 × 400 m2 plots to determine the species-specific determinants of mortality and their influence on subsequent species recruitment. Nine soil physical-chemical properties were examined in addition to slope position, mean DBH and total number of trees. Generalized linear models analyzed relationships between these variables and mortality and recruitment. Mortality was positively associated with increasing average diameter and negatively to high soil pH and total nitrogen content. Recruitment models indicate that Populus davidiana recruitment was positively affected by available phosphorus and mortality, and negatively related to mean DBH. Slope position was the most important contributing variable to Betula platyphylla recruitment. With Quercus mongolica recruitment, soil variables played an important role. These results suggest that tree mortality is affected by soil properties, topography and tree size in China's forest-steppe ecotone, and may improve our understanding of species mortality and contribute to improved forest management.


1971 ◽  
Vol 22 (6) ◽  
pp. 931
Author(s):  
MT Seeliger ◽  
RJ French

Changes in soil properties in a long-term factorial experiment with nitrogen, phosphorus, and potassium fertilizer at the Nuriootpa Viticultural Research Station in South Australia were measured after 23 years of application. The measurements were related to vine yield responses reported earlier. Phosphorus, broadcast as superphosphate, gave excessively high available phosphorus levels in the top 6 in, of soil, but yield responses were delayed for 8 years until the slow-moving phosphorus reached the 6–12 in. layer where the feeder roots occurred. Broadcasting superphosphate was a wasteful and inefficient means of applying phosphorus in this environment. About three-quarters of the phosphorus applied could be measured in the top foot of soil. Nitrogen applied as sulphate of ammonia reduced pH significantly in the top 18 in. of soil, with the biggest reduction of 1.5 units to pH 5.0 in the 6–12 in. layer. As this acidity developed it probably caused the depression in vine vigour and yield. Potassium levels were high and not limiting in the unfertilized soils. The relation between nutrients supplied in the fertilizers and nutrients removed in the grapes is discussed.


1992 ◽  
Vol 68 (05) ◽  
pp. 570-576 ◽  
Author(s):  
Mary A Selak

SummaryWe have previously demonstrated that human neutrophil cathepsin G is a strong platelet agonist that binds to a specific receptor. This work describes the effect of neutrophil elastase on cathepsin G-induced platelet responses. While platelets were not activated by high concentrations of neutrophil elastase by itself, elastase enhanced aggregation, secretion and calcium mobilization induced by low concentrations of cathepsin G. Platelet aggregation and secretion were potentiated in a concentration-dependent manner by neutrophil elastase with maximal responses observable at 200 nM. Enhancement was observed when elastase was preincubated with platelets for time intervals of 10–60 s prior to addition of a low concentration of cathepsin G and required catalytically-active elastase since phenylmethanesulphonyl fluoride-inhibited enzyme failed to potentiate cell activation. Neutrophil elastase potentiation of platelet responses induced by low concentrations of cathepsin G was markedly inhibited by creatine phosphate/creatine phosphokinase and/or indomethacin, indicating that the synergism between elastase and cathepsin G required the participation of ADP and thromboxane A2. On the other hand, platelet responses were not attenuated by the PAF antagonist BN 52021, signifying that PAF-acether did not play a role in elastase potentiation. At higher concentrations porcine pancreatic elastase exhibits similar effects to neutrophil elastase, demonstrating that the effect of elastase was not unique to the neutrophil protease. While neutrophil elastase failed to alter the ability of cathepsin G to hydrolyze a synthetic chromogenic substrate, preincubation of platelets with elastase increased the apparent affinity of cathepsin G binding to platelets. In contrast to their effect on cathepsin G-induced platelet responses, neither neutrophil nor pancreatic elasatse potentiated aggregation or dense granule release initiated by ADP, PAF-acether, arachidonic acid or U46619, a thromboxane A2 mimetic. Moreover, unlike its effect on cathepsin G, neutrophil elastase inhibited thrombin-induced responses. The current observations demonstrate that elastase can potentiate platelet responses mediated by low concentrations of cathepsin G, suggesting that both enzymes may function synergistically to activate platelets under conditions where neutrophil degranulation occurs.


Sign in / Sign up

Export Citation Format

Share Document