Effects of Soil Environment on Field Efficacy of Microbial Inoculants

Author(s):  
Ekta Khare ◽  
Naveen K. Arora
2019 ◽  
Author(s):  
Chem Int

This work is aimed at developing a mathematical model equation that can be used to predict the fate of contaminant in the soil environment. The mathematical model was developed based on the fundamental laws of conservation and the equation of continuity given asand was resolved to obtain a quadratic equation of the form C(X) = DX2+vX+f. The developed equation was then used to fit the experimental data that were obtained from the Physio-chemical analysis of the soil samples which were obtained at various depths; within the vicinity of the H & H Asphalt plant Company, located at Enito 3 in Ahoada West L.G.A, River State, Nigeria. The Experimental and Model results obtained from the Calculation and Simulation of the developed models were compared numerically and graphically as presented in this work. It was observed that there is reasonable level of agreement between the three results. The polynomial of the curve was established to ascertain the validity of the model; this was done for all the parameters that were analyzed. From the findings the model developed can be used to predict the concentration of a chemical pollutant at various depths. The reliability of the model developed was established giving the fact that through this quadratic equation the diffusivity (coefficient of diffusion), the water velocity and the irreversible reaction decay rate could be determined.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1464
Author(s):  
Maja Čačija ◽  
Renata Bažok ◽  
Majda Kolenc ◽  
Tena Bujas ◽  
Zrinka Drmić ◽  
...  

Colorado potato beetle (CPB) is an economic pest of potato that has developed resistance to all classes of chemical insecticides, thus requiring alternative control measures. As a potential solution, entomopathogenic nematodes (EPNs) have proven effective in suppressing this pest, but their efficacy against overwintering generations of CPB in Croatia has not been sufficiently researched. The aim of this two-year (2018–2019) field study was to determine the efficacy of Steinernema feltiae and Steinernema carpocapsae applied to overwintering CPB adults. EPNs were applied at three doses (7.5 mil./10 m2, 5.0 mil./10 m2 (the recommended dose) and 2.5 mil./10 m2) by watering the soil where the adults were overwintering. The first-year results were satisfactory for both EPNs: the efficacy of S. feltiae ranged from 79.03% to 100.00%, while the efficacy of S. carpocapsae ranged from 77.32% to 96.22%. In the second year, the highest efficacy (69.57%) was obtained using the recommended dose of S. feltiae. Although the results are not consistent across the two years of our study and suggest further research, they indicate that EPNs have great potential in controlling overwintering CPB generations to reduce first generation abundance and damage, and also to prevent the spread of new generations to surrounding potato growing areas.


2021 ◽  
Vol 13 (10) ◽  
pp. 5612
Author(s):  
Shu-Yuan Pan ◽  
Cheng-Di Dong ◽  
Jenn-Feng Su ◽  
Po-Yen Wang ◽  
Chiu-Wen Chen ◽  
...  

Biochar is a carbon-rich material prepared from the pyrolysis of biomass under various conditions. Recently, biochar drew great attention due to its promising potential in climate change mitigation, soil amendment, and environmental control. Obviously, biochar can be a beneficial soil amendment in several ways including preventing nutrients loss due to leaching, increasing N and P mineralization, and enabling the microbial mediation of N2O and CO2 emissions. However, there are also conflicting reports on biochar effects, such as water logging and weathering induced change of surface properties that ultimately affects microbial growth and soil fertility. Despite the voluminous reports on soil and biochar properties, few studies have systematically addressed the effects of biochar on the sequestration of carbon, nitrogen, and phosphorus in soils. Information on microbially-mediated transformation of carbon (C), nitrogen (N), and phosphorus (P) species in the soil environment remains relatively uncertain. A systematic documentation of how biochar influences the fate and transport of carbon, phosphorus, and nitrogen in soil is crucial to promoting biochar applications toward environmental sustainability. This report first provides an overview on the adsorption of carbon, phosphorus, and nitrogen species on biochar, particularly in soil systems. Then, the biochar-mediated transformation of organic species, and the transport of carbon, nitrogen, and phosphorus in soil systems are discussed. This review also reports on the weathering process of biochar and implications in the soil environment. Lastly, the current knowledge gaps and priority research directions for the biochar-amended systems in the future are assessed. This review focuses on literatures published in the past decade (2009–2021) on the adsorption, degradation, transport, weathering, and transformation of C, N, and P species in soil systems with respect to biochar applications.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1269
Author(s):  
David K. Mfuti ◽  
Amanuel Tamiru ◽  
William D. J. Kirk ◽  
Adeyemi O. Akinyemi ◽  
Heather Campbell ◽  
...  

The potential of semiochemicals to lure insect pests to a trap where they can be killed with biopesticides has been demonstrated as an eco-friendly pest management alternative. In this study, we tested two recently characterized male-produced aggregation pheromones of the bean flower thrips Megalurothrips sjostedti (Trybom), namely (R)-lavandulyl 3-methylbutanoate (major) and (R)-lavandulol (minor), for their field efficacy. Moreover, compatibility of these pheromones and two other thrips attractants, Lurem-TR and neryl (S)-2-methylbutanoate, with the entomopathogenic fungus (EPF) Metarhizium anisopliae ICIPE 69 has been determined. Our study revealed that the M. sjostedti aggregation pheromones have dose-dependent antifungal effects on the EPF viability, but showed no fungistatic effect at a field-realistic dose for attraction of thrips. (R)-lavandulyl 3-methylbutanoate had similar antifungal effects as neryl (S)-2-methylbutanoate 8 days after exposure; whereas, Lurem-TR had a stronger antifungal effect than other thrips attractants. In the semi-field experiments, all autoinoculation devices maintained at least 86% viability of M. anisopliae conidia after 12 days of exposure. Field trials demonstrated for the first time that (R)-lavandulyl 3-methylbutanoate increases trap catches. Our findings pave a way for designing a lure-and-kill thrips management strategy to control bean flower thrips using autoinoculation devices or spot spray application.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 314
Author(s):  
Petros Tsiantas ◽  
Evangelia N. Tzanetou ◽  
Helen Karasali ◽  
Konstantinos M. Kasiotis

Soil constitutes a central environmental compartment that, due to natural and anthropogenic activities, is a recipient of several contaminants. Among them, organochlorine pesticides are of major concern, even though they have been banned decades ago in the European Union, due to their persistence and the health effects they can elicit. In the presented work, a gas chromatographic tandem mass spectrometric (GC-MS/MS) developed method was applied to soil samples after the suspected and potential use of formulations containing organochlorine active substance. One soil sample was positive to dieldrin at 0.018 mg kg−1. Predicted environmental concentration in soil (PECsoil) considering a single application of this active substance potentially attributed the finding in its past use. The subsequent health risk assessment showed negligible non-carcinogenic risk and tolerable carcinogenic risk. The latter signifies that repetitive and prolonged sampling can unveil the pragmatic projection of persistent chemicals’ residues in the soil.


Author(s):  
Zhiting Ma ◽  
Qi Wang ◽  
Xiaowei Wang ◽  
Xuesen Chen ◽  
Yanfang Wang ◽  
...  

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