scholarly journals Movement of Dichlorvos in Farm Soils: Batch and Column Studies.

Author(s):  
Nahuel Bustos ◽  
Diego Grassi ◽  
Alicia Fernández Cirelli ◽  
Analia Iriel

Abstract Soils are the principal environmental fate of pesticides in agricultural areas. Thus, the kinetics, extension, and strength of the adsorption process become critical. Dichlorvos (DDVP) is an organophosphorous pesticide that is used both in agriculture and livestock production. Sorption/desorption assays of DDVP in two agricultural soils (with different textural characteristics) from Pampa Plain (Argentina) were performed in both batch and column systems. From batch studies, kinetics and sorption/desorption equilibrium parameters were estimated. Our results showed that the maxima adsorption is reached after 30 h of time of contact and followed a pseudo-first-order rate. Adsorption/desorption data were well fitted to the Freundlich model obtaining high adsorption constants of 90 mg(1-1/n) mL(1/n) g-1 and 21 mg(1-1/n) mL(1/n) g-1 for the clay loam and sandy loam soil, respectively. The isotherms were non-linear in both cases and the desorption process was unfavourable. Also, positive hysteresis was present for the sandy loam soil. From column studies, breakthrough curves were used to evaluate the mobility of DDVP in the soils at 1, 10, and 50 mg L-1 of DDVP. Eluted profiles were asymmetrical as well they presented retardation effects that were in connection with the results in batch conditions. Non-equilibrium sorption was stated for the DDVP movement through columns. Thus, high mobility was observed for DDVP in both soils despite their textural differences.

Agronomie ◽  
2002 ◽  
Vol 22 (7-8) ◽  
pp. 731-738 ◽  
Author(s):  
Roland Harrison ◽  
Sharon Ellis ◽  
Roy Cross ◽  
James Harrison Hodgson

2020 ◽  
Vol 18 (4) ◽  
pp. 84-87
Author(s):  
Yu.V. Leonova ◽  
◽  
T.A. Spasskaya ◽  

The change in the microbiological activity of sod-podzolic sandy loam soil when using coffee waste and sewage sludge as a fertilizer for oats in comparison with traditional fertilizers is considered. During the study, it was determined that the predominant groups were bacteria and actinomycetes. Bacilli and fungi are few in number. The introduction of sewage sludge and coffee waste into the sod-podzolic sandy loam soil at a dose of 10 t / ha increases the activity of the microflora of the sod-podzolic sandy loam soil, which increases the effective and potential fertility.


2004 ◽  
Vol 3 (1) ◽  
pp. 316
Author(s):  
M. Saleem Akhtar ◽  
Tammo S. Steenhuis ◽  
Brian K. Richards ◽  
Murray B. McBride

2021 ◽  
Vol 11 (12) ◽  
pp. 5499
Author(s):  
Nihal D. Salman ◽  
György Pillinger ◽  
Muammel M. Hanon ◽  
Péter Kiss

The applicability of the typical pressure–sinkage models used to characterize the soil’s bearing properties is limited to homogeneous soils (infinite thickness) that have no hard layer. At a given depth, a hard layer can have a considerable impact on the soil’s load-bearing capacity. It is thus necessary to alter the pressure–sinkage equation by taking this condition into account when assessing the load-bearing capacity. The present paper aims to determine a simple, high-fidelity model, in terms of soil characterization, that can account for the hard layer affection. To assess hard layer affection in this paper, a plate sinkage test (bevameter) was conducted on sandy loam soil. To this end, the soil was prepared by considering three bulk densities and two soil thickness levels at 7–9% moisture content levels. According to the results, this paper put forth a new perspective and related equations for characterizing bearing performance. The sinkage modulus (k) is an intrinsic soil parameter that has a determined unit of N/cm2 and is significant for managing the bearing performance. The results showed that the new modulus sinkage model incorporates the main factor of the rigid layer effect involving high fidelity that the conventional models have failed to account for.


1978 ◽  
Vol 14 (3) ◽  
pp. 253-259 ◽  
Author(s):  
H. N. Verma ◽  
S. S. Prihar ◽  
Ranjodh Singh ◽  
Nathu Singh

SUMMARYField experiments were conducted for 4 years to study the yield of ‘kharif’ and ‘rabi’ crops grown in sequence on two soils differing in water-holding capacity. The results indicated that drought caused greater reduction in yield of rainy-season crops on loamy sand than on sandy loam soil. In low retentivity soil it was more profitable to raise a single crop of wheat on soil-stored water. In sandy loam soil of higher retentivity, two crops a year gave much higher yields than a single crop. Of the sequences tried, maize followed by wheat gave the highest and most stable yields. For ‘rabi’ crops, stored water showed a better yield response than an equivalent amount of rain during the growing season.


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