Aerobic soil metabolism of metsulfuron-methyl

To determine whether long-term sewage treatment can take place without a pollution risk for soil and groundwater, samples from sewage irrigation fields in West Berlin which have been in use since about 1890 were analyzed for enteric viruses and microorganisms. Enteric viruses were detected in only seven samples from a total number of eighty seven taken from different soil depths. With only one exception, no viruses were found below 60 cm. No viruses were detected in groundwater samples. Long-term sewage irrigation did not result in significant changes in the colony courts of aerobic soil bacteria, but the counts of anaerobic bacteria and actinomycetes were slightly elevated and those of microscopic fungi slightly decreased. Potentially pathogenic bacteria were not detected in soil below 90 cm.

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IMPACT OF WHEAT ESTABLISHMENT METHODS AND WEED MANAGEMENT PRACTICES ON WEED FLORA, YIELD AND NUTRIENT UPTAKE OF WHEAT IN RICE-WHEAT CROPPING SYSTEM

Journal of AgriSearch ◽

10.21921/jas.v6i02.15754 ◽

2019 ◽

Vol 6 (02) ◽

Cited By ~ 1

Author(s):

MOHAN SINGH ◽

OMBIR SINGH ◽

ROHITASAV SINGH

Keyword(s):

Nutrient Uptake ◽

Weed Management ◽

Conventional Tillage ◽

Research Centre ◽

Zero Tillage ◽

Phalaris Minor ◽

Weed Population ◽

Metsulfuron Methyl ◽

Transplanted Rice ◽

Weed Flora

A field experiment was conducted at the Crop Research Centre of Govind Ballabh Pant University of Agriculture and Technology Pantnagar, Udham Singh Nagar during continuous two years to study the weed flora, yield and nutrient uptake of wheat (Triticum aestivum L.) under different wheat establishment methods in main plots and seven weed management in sub plots. Phalaris minor was the most dominant weed at 60 DAS contributed 55.0 per cent of total weed population. Melilotusindica was the major non grassy weeds in wheat which contributed 11 per cent to total weed population during respective years. Sowing of wheat with zero tillage significantly reduced the Phalaris minor density as compared to conventionally tilled wheat after transplanted rice, 60 per cent Phalaris minor emerged from 0-3 cm in reduced and conventional tillage where as in zero tillage after transplanted rice there was 55 per cent emergence from 0-3 cm layer.The highest grain yield was obtained in two hand weedings done at 30 and 60 DAS and was at par with Isoproturon 1.0 kg ha-1 + Metsulfuron methyl 4 g ha-1 at 30 DAS and Clodinafop – Propargyl 60 g ha-1 at 30 DAS fb. Metsulfuron methyl 4 g ha-1 at 37 DAS. Zero tillage resulted in significantly higher uptake of NPK by wheat plants as compared to conventional tillage, whereas reduced tillage recorded minimum NPK, which was significantly lower over the other treatments of wheat establishment methods.

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DFT study on the hydrolysis of metsulfuron-methyl: A sulfonylurea herbicide

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633618500505 ◽

2018 ◽

Vol 17 (08) ◽

pp. 1850050 ◽

Cited By ~ 1

Author(s):

Qiuhan Luo ◽

Gang Li ◽

Junping Xiao ◽

Chunhui Yin ◽

Yahui He ◽

...

Keyword(s):

Free Energy ◽

Water Molecule ◽

Carbonyl Group ◽

Energy Barrier ◽

Density Functional ◽

Free Energy Barrier ◽

Functional Theory ◽

Metsulfuron Methyl ◽

Catalytic Role ◽

Hydrolysis Of

Sulfonylureas are an important group of herbicides widely used for a range of weeds and grasses control particularly in cereals. However, some of them tend to persist for years in environments. Hydrolysis is the primary pathway for their degradation. To understand the hydrolysis behavior of sulfonylurea herbicides, the hydrolysis mechanism of metsulfuron-methyl, a typical sulfonylurea, was investigated using density functional theory (DFT) at the B3LYP/6-31[Formula: see text]G(d,p) level. The hydrolysis of metsulfuron-methyl resembles nucleophilic substitution by a water molecule attacking the carbonyl group from aryl side (pathway a) or from heterocycle side (pathway b). In the direct hydrolysis, the carbonyl group is directly attacked by one water molecule to form benzene sulfonamide or heterocyclic amine; the free energy barrier is about 52–58[Formula: see text]kcal[Formula: see text]mol[Formula: see text]. In the autocatalytic hydrolysis, with the second water molecule acting as a catalyst, the free energy barrier, which is about 43–45[Formula: see text]kcal[Formula: see text]mol[Formula: see text], is remarkably reduced by about 11[Formula: see text]kcal[Formula: see text]mol[Formula: see text]. It is obvious that water molecules play a significant catalytic role during the hydrolysis of sulfonylureas.

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Biodegradable Polymeric Foams Based on Modified Castor Oil, Styrene, and Isobornyl Methacrylate

Polymers ◽

10.3390/polym13111872 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1872

Author(s):

James Anthony Dicks ◽

Chris Woolard

Keyword(s):

Young’S Modulus ◽

Castor Oil ◽

Young's Modulus ◽

Attenuated Total Reflection ◽

Infrared Spectrometry ◽

Cell Diameter ◽

Polymeric Foams ◽

Reactive Diluent ◽

Structure Property ◽

Aerobic Soil

The environmental issues of petroleum-derived polymeric foams have necessitated seeking renewable alternatives. This work aims to prepare renewable free-radically polymerized polymeric foams with the ability to biodegrade. Furthermore, this work attempted to incorporate a bio-based reactive diluent, which has not been reported in the literature. The synthesis of maleated castor oil glycerides was performed with products analyzed by Fourier transform infrared spectrometry using attenuated total reflection (ATR-FTIR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy. Polymeric foams were prepared using maleated castor oil glycerides via free radical copolymerization with styrene and isobornyl methacrylate as reactive diluents. Scanning electron microscopy (SEM) was used to determine anisotropic macrocellular morphology, with log-normal cell diameter distributions. The compressive mechanical and energy absorption properties were investigated; the polymeric foams displayed Young’s modulus up to 26.85 ± 1.07 MPa and strength up to 1.11 ± 0.021 MPa using styrene as the reactive diluent, and Young’s modulus up to 1.38 ± 0.055 MPa and strength up to 0.088 MPa when incorporating isobornyl methacrylate. Furthermore, a thorough analysis of the cellular structure–property relationships was performed, indicating relationships to cell diameter, cell wall thickness and apparent density. The polymeric foams displayed rapid mass loss in an aerobic soil environment with multiple erosion sites revealed by SEM. In conclusion, renewable polymeric foams with excellent compressive properties were achieved using styrene as reactive diluent, but the incorporation of isobornyl methacrylate decreased strength-related properties.

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