scholarly journals Portable penetrometer for agricultural soil: sensitivity test to identify critical compaction depth

2010 ◽  
Vol 34 (6) ◽  
pp. 1823-1829 ◽  
Author(s):  
João Carlos Medeiros ◽  
Getulio Coutinho Figueiredo ◽  
Álvaro Luiz Mafra
Keyword(s):  
Plant Growth ◽  
Mechanical Strength ◽  
Plant Species ◽  
Soil Compaction ◽  
Agricultural Soil ◽  
Agricultural Soils ◽  
Soil Resistance ◽  
Negative Effects ◽  
Physical Conditions ◽  
Soil Sensitivity

To express the negative effects of soil compaction, some researchers use critical values for soil mechanical strength that severely impair plant growth. The aim of this study was to identify this critical compaction depth, to test the functionality of a new, portable penetrometer developed from a spring dynamometer, and compare it to an electronic penetrometer traditionally used in compaction studies of agricultural soils. Three soils with distinct texture were conventionally tilled using a disk plow, and cultivated with different plant species. The critical soil resistance defined to establish critical compaction depth was equal to 1.5 MPa. The results of the new equipment were similar to the electronic penetrometer, indicating its viability as a tool for assessing the soil physical conditions for plant growth.

scholarly journals Metal bioaccumulation alleviates the negative effects of herbivory on plant growth

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Grazieli F. Dueli ◽  
Og DeSouza ◽  
Servio P. Ribeiro
Keyword(s):  
Plant Growth ◽  
Metal Concentration ◽  
Plant Species ◽  
Metal Ion ◽  
Natural Habitat ◽  
Plant Responses ◽  
Metal Bioaccumulation ◽  
Negative Effects ◽  
Quantitative Evidence ◽  
Soil Metal

AbstractMetalliferous soils can selectively shape plant species’ physiology towards tolerance of high metal concentrations that are usually toxic to organisms. Some adapted plant species tolerate and accumulate metal in their tissues. These metals can serve as an elemental defence but can also decrease growth. Our investigation explored the capacity of natural metal accumulation in a tropical tree species, Eremanthus erythropappus (Asteraceae) and the effects of such bioaccumulation on plant responses to herbivory. Seedlings of E. erythropappus were grown in a glasshouse on soils that represented a metal concentration gradient (Al, Cu, Fe, Mn and Zn), and then the exposed plants were fed to the herbivores in a natural habitat. The effect of herbivory on plant growth was significantly mediated by foliar metal ion concentrations. The results suggest that herbivory effects on these plants change from negative to positive depending on soil metal concentration. Hence, these results provide quantitative evidence for a previously unsuspected interaction between herbivory and metal bioaccumulation on plant growth.

The importance of nitrate in ameliorating the effects of ammonium and urea nutrition on plant development: the relationships with free polyamines and plant proline contents

2005 ◽  
Vol 32 (11) ◽  
pp. 1057 ◽  
Author(s):  
Fabrice Houdusse ◽  
Angel M. Zamarreño ◽  
Maria Garnica ◽  
Josemaria García-Mina
Keyword(s):  
Plant Growth ◽  
Plant Species ◽  
Nutrient Solution ◽  
Nitrogen Nutrition ◽  
Specific Effect ◽  
Ammonium Assimilation ◽  
Negative Effects ◽  
Ammonium Accumulation ◽  
Free Polyamines ◽  
Specific Pathway

In order to investigate the possible involvement of free polyamines and proline in the mechanism underlying the action of nitrate in correcting the negative effects associated with ammonium and urea nutrition in certain plant species, we studied plant contents of free polyamines and proline associated with nitrogen nutrition involving different nitrogen forms (nitrate, ammonium, urea) in two plant species, wheat and pepper. The results showed that ammonium nutrition and, to a lesser extent, urea nutrition were associated with significant increases in plant putrescine content that were well correlated with reductions in plant growth. These negative effects of ammonium and urea nutrition were corrected by the presence of nitrate in the nutrient solution; the presence of nitrate was also related to a significant decrease in the plant putrescine content. These results are compatible with a specific effect of nitrate reducing ammonium accumulation through the improvement of ammonium assimilation. As for the plant proline content, in pepper a slight increase in this parameter was associated with ammonium and urea nutrition, but it was also decreased by the presence of nitrate in the nutrient solution. These changes, however, were not so clearly related to the variations in plant growth as in the case of putrescine content. These results are compatible with the hypothesis that putrescine biosynthesis might be related to proline degradation by a specific pathway related to ammonium detoxification.

MORPHOLOGICAL AND BIOCHEMICAL RESPOSES OF COW PEA (CV. PUSA BARSATI) GROWN ON FLY ASH AMENDED SOIL IN PRESENCE AND ABSENCE OF MELOIDOGYNE JAVANICA AND RHIZOBIUM LEGUMINOSARUM

1970 ◽  
Vol 17 ◽  
pp. 17-22 ◽  
Author(s):  
Kamal Singh ◽  
A. A. Khan ◽  
Iram Khan ◽  
Rose Rizvi ◽  
M. Saquib
Keyword(s):  
Fly Ash ◽  
Plant Growth ◽  
Rhizobium Leguminosarum ◽  
Growth Yield ◽  
Maximum Growth ◽  
Meloidogyne Javanica ◽  
Growth And Yield ◽  
Negative Effects ◽  
Positive Effects ◽  
Insignificant Difference

Plant growth, yield, pigment and protein content of cow-pea were increased significantly at lower levels (20 and 40%) of fly ash but reverse was true at higher levels (80 and 100%). Soil amended by 60% fly ash could cause suppression in growth and yield in respect to 40% fly ash treated cow-pea plants but former was found at par with control (fly ash untreated plants). Maximum growth occurred in plants grown in soil amended with 40% fly ash. Nitrogen content of cow-pea was suppressed progressively in increasing levels of fly ash. Moreover,  Rhizobium leguminosarum  influenced the growth and yield positively but Meloidogyne javanica caused opposite effects particularly at 20 and 40% fly ash levels. The positive effects of R. leguminosarum were marked by M. javanica at initial levels. However, at 80 and 100% fly ash levels, the positive and negative effects of R. leguminosarum and/or M. javanica did not appear as insignificant difference persist among such treatments.Key words:  Meloidogyne javanica; Rhizobium leguminosarum; Fly ash; Growth; YieldDOI: 10.3126/eco.v17i0.4098Ecoprint An International Journal of Ecology Vol. 17, 2010 Page: 17-22 Uploaded date: 28 December, 2010  

Zinc oxide nanoparticles help to enhance plant growth and alleviate abiotic stress: A review

2020 ◽  
Vol 21 ◽  
Author(s):  
Mohammad Faizan ◽  
Fangyuan Yu ◽  
Chen Chen ◽  
Ahmad Faraz ◽  
Shamsul Hayat
Keyword(s):  
Zinc Oxide ◽  
Plant Growth ◽  
Abiotic Stresses ◽  
Zinc Oxide Nanoparticles ◽  
Growth And Yield ◽  
Oxide Nanoparticles ◽  
Main Concern ◽  
Negative Effects ◽  
Zno Nps ◽  
Agricultural Yield

: Abiotic stresses arising from atmosphere change belie plant growth and yield, leading to food reduction. The cultivation of a large number of crops in the contaminated environment is a main concern of environmentalists in the present time. To get food safety, a highly developed nanotechnology is a useful tool for promoting food production and assuring sustainability. Nanotechnology helps to better production in agriculture by promoting the efficiency of inputs and reducing relevant losses. This review examines the research performed in the past to show how zinc oxide nanoparticles (ZnO-NPs) are influencing the negative effects of abiotic stresses. Application of ZnO-NPs is one of the most effectual options for considerable enhancement of agricultural yield globally under stressful conditions. ZnO-NPs can transform the agricultural and food industry with the help of several innovative tools in reversing oxidative stress symptoms induced by abiotic stresses. In addition, the effect of ZnO-NPs on physiological, biochemical, and antioxidative activities in various plants have also been examined properly. This review summarizes the current understanding and the future possibilities of plant-ZnO-NPs research.

scholarly journals Ammonia-oxidizing archaea are integral to nitrogen cycling in a highly fertile agricultural soil

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Laibin Huang ◽  
Seemanti Chakrabarti ◽  
Jennifer Cooper ◽  
Ana Perez ◽  
Sophia M. John ◽  
...  
Keyword(s):  
Nitrogen Cycle ◽  
Agricultural Soil ◽  
Agricultural Soils ◽  
Ammonia Oxidizing Bacteria ◽  
Central Process ◽  
Soil Nitrification ◽  
Plant Nitrogen ◽  
Ammonia Oxidizing Archaea ◽  
Activity Measurements ◽  
Nitrite Oxidizing Bacteria

AbstractNitrification is a central process in the global nitrogen cycle, carried out by a complex network of ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), complete ammonia-oxidizing (comammox) bacteria, and nitrite-oxidizing bacteria (NOB). Nitrification is responsible for significant nitrogen leaching and N2O emissions and thought to impede plant nitrogen use efficiency in agricultural systems. However, the actual contribution of each nitrifier group to net rates and N2O emissions remain poorly understood. We hypothesized that highly fertile agricultural soils with high organic matter mineralization rates could allow a detailed characterization of N cycling in these soils. Using a combination of molecular and activity measurements, we show that in a mixed AOA, AOB, and comammox community, AOA outnumbered low diversity assemblages of AOB and comammox 50- to 430-fold, and strongly dominated net nitrification activities with low N2O yields between 0.18 and 0.41 ng N2O–N per µg NOx–N in cropped, fallow, as well as native soil. Nitrification rates were not significantly different in plant-covered and fallow plots. Mass balance calculations indicated that plants relied heavily on nitrate, and not ammonium as primary nitrogen source in these soils. Together, these results imply AOA as integral part of the nitrogen cycle in a highly fertile agricultural soil.

Interactive effect of biochar and plant growth-promoting bacterial endophytes on ameliorating salinity stress in maize

2015 ◽  
Vol 42 (8) ◽  
pp. 770 ◽  
Author(s):  
Saqib Saleem Akhtar ◽  
Mathias Neumann Andersen ◽  
Muhammad Naveed ◽  
Zahir Ahmad Zahir ◽  
Fulai Liu
Keyword(s):  
Plant Growth ◽  
Salinity Stress ◽  
Crop Production ◽  
Interactive Effect ◽  
Nutrient Balance ◽  
Bacterial Strains ◽  
Negative Effects ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Salt Affected Soils

The objective of this work was to study the interactive effect of biochar and plant growth-promoting endophytic bacteria containing 1-aminocyclopropane-1-carboxylate deaminase and exopolysaccharide activity on mitigating salinity stress in maize (Zea mays L.). The plants were grown in a greenhouse under controlled conditions, and were subjected to separate or combined treatments of biochar (0% and 5%, w/w) and two endophytic bacterial strains (Burkholderia phytofirmans (PsJN) and Enterobacter sp. (FD17)) and salinity stress. The results indicated that salinity significantly decreased the growth of maize, whereas both biochar and inoculation mitigated the negative effects of salinity on maize performance either by decreasing the xylem Na+ concentration ([Na+]xylem) uptake or by maintaining nutrient balance within the plant, especially when the two treatments were applied in combination. Moreover, in biochar-amended saline soil, strain FD17 performed significantly better than did PsJN in reducing [Na+]xylem. Our results suggested that inoculation of plants with endophytic baterial strains along with biochar amendment could be an effective approach for sustaining crop production in salt-affected soils.

scholarly journals Effect of Bentonite and Barley Straw on the Restoration of the Biological Quality of Agriculture Soil Contaminated with the Herbicide Successor T 550 SE

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
Jadwiga Wyszkowska ◽  
Monika Tomkiel ◽  
Agata Borowik ◽  
Małgorzata Baćmaga ◽  
Jan Kucharski
Keyword(s):  
Agricultural Soil ◽  
Plant Protection ◽  
Spring Barley ◽  
Biochemical Properties ◽  
Barley Straw ◽  
Negative Effects ◽  
Soil Quality Index ◽  
Oligotrophic Bacteria ◽  
Organotrophic Bacteria ◽  
Environmentally Safe

Environmentally safe ways are sought to prevent the accumulation and to accelerate the degradation of herbicide active substances in agricultural soil. This study aimed to determine the effectiveness of finely-ground barley straw and bentonite in mitigating the effects of agricultural soil contamination with Successor T 550 SE. This herbicide was applied in the following doses: 0, 0.73, and 14.63 mg of the active substance per kg. The bentonite and spring barley straw were used at 10 g/kg. The action of these additives was compared to soil without the addition of straw and bentonite. The application of the experimental herbicide disturbed microbial systems, such as organotrophic bacteria, oligotrophic bacteria and their spores, actinobacteria, and fungi. A positive response to the herbicide dose of 14.63 mg a.s./kg was observed only for spores of oligotrophic bacteria. Further disturbances were observed in the agricultural soil biochemical properties, i.e., in the activity of dehydrogenases, urease, catalase, acid, and alkaline phosphatase, arylsulfatase, and β-glucosidase. A significant decrease in the activity of dehydrogenases, acid phosphatase, and arylsulfatase was observed following the application of 14.63 mg a.s./kg. The yield of maize decreased following the application of the analysed plant protection agent. Based on the soil quality index (BA), the addition of straw was more effective in restoring soil homeostasis than bentonite. Both bentonite and straw can be successfully used to improve agricultural soil biological activity. However, more effective mitigation of the negative effects of the herbicide in soil was observed in objects supplemented with barley straw. This improved the microbiological and biochemical properties of the soil. Barley straw was more effective than bentonite in restoring soil biological balance.

scholarly journals LOCAL CONTRIBUTION OF A QUANTUM CONDENSATE TO THE VACUUM ENERGY DENSITY

2003 ◽  
Vol 18 (10) ◽  
pp. 683-690 ◽  
Author(s):  
GIOVANNI MODANESE
Keyword(s):  
Energy Density ◽  
Vacuum Energy ◽  
Casimir Effect ◽  
Landau Equation ◽  
Vacuum Energy Density ◽  
Negative Effects ◽  
Ginzburg Landau ◽  
Physical Conditions ◽  
Local Contribution ◽  
Gravitational Vacuum

We evaluate the local contribution gμνL of coherent matter with Lagrangian density L to the vacuum energy density. Focusing on the case of superconductors obeying the Ginzburg–Landau equation, we express the relativistic invariant density L in terms of low-energy quantities containing the pairs density. We discuss under which physical conditions the sign of the local contribution of the collective wave function to the vacuum energy density is positive or negative. Effects of this kind can play an important role in bringing the local changes in the amplitude of gravitational vacuum fluctuations — a phenomenon reminiscent of the Casimir effect in QED.

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