Persistence and binding of DDT and gamma-HCH in a sandy loam soil under field conditions in Delhi, India

1988 ◽  
Vol 22 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Thomas Samuel ◽  
Hari C. Agarwal ◽  
Madathil K. K. Pillai
1981 ◽  
Vol 61 (1) ◽  
pp. 11-17
Author(s):  
E.B. ROSLYCKY

Terbacil in concentrations up to 500 μg∙g−1 of sandy loam soil had little effect on populations of actinomycetes, bacteria, and fungi under laboratory and field conditions during a period of 5 mo. Concentrations up to 700 μg of terbacil∙mL−1 did not affect the in vitro growth of 111 strains of agriculturally important microorganisms, including effective, parasitic, and lysogenic rhizobia from seven cross-inoculation groups, pathogenic, attenuated, and saprophytic agrobacteria, azotobacters, and other bacteria, actinomycetes, and fungi. Terbacil inhibited the respiration of total soil microbiota, of bacteria, and of fungi at all concentrations tested. By contrast, it stimulated the respiration of actinomycetes at concentrations up to 500 μg∙mL−1 and partially inhibited it at 700 μg∙mL−1. Replication of bacterial and actinomycete isolates showed minimal inhibition by the extreme concentrations.


Agronomy ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 183 ◽  
Author(s):  
Mawiyah Mahmud ◽  
Rosazlin Abdullah ◽  
Jamilah Yaacob

Vermicompost is the product of composting or breaking down organic matter through the use of earthworms. It is rich in essential plant nutrients, and has the ability to enhance the condition and increase the quality of the soil. In the present study, a field trial was conducted from January 2015 until March 2016 to elucidate the effects of vermicompost application (compared to supplementation with chemical fertilizer and no fertilizer) on the sandy loam soil and plant nutrients of pineapple (Ananas comosus var. MD2). The morphophysiology and yield performance of MD2 pineapple grown with vermicompost in the field were also evaluated. In this study, vermicompost was applied onto the sandy loam soils during transplanting, followed by a second application at seven MAP (months after planting) at the rate of 10 t ha−1. On the other hand, the chemical fertilizer was applied based on the normal conventional cultivation practice. The soil and D-leaf samples at six MAP (S1) and during the red bud stage (S2; 10 MAP) were used to determine the soil and plant nutrient contents. The morphology of the plants was evaluated every month, and the fruits that were produced were subjected to quality analysis. Data analysis revealed that soil pH was increased after a second supplementation of vermicompost and contained significantly higher total N (0.15%) in the soils compared to the control (0.07%). There was no significant difference between plants supplied with chemical fertilizer and vermicompost in terms of plant height, number of leaves, or the length and width of D-leaves. However, different fertilization treatments were found to affect the yield and physical characteristics of the resulting fruits. Plants supplied with chemical fertilizer produced the highest fruit yield (136.97 t ha−1) with the largest fruit size, followed by vermicompost (121.39 t ha−1) and the control (94.93 t ha−1). However, fruits supplied with vermicompost were observed to have the smallest crowns. Taken together, these results indicated that the use of vermicompost produced pineapple plants with excellent growth performance, comparable to that obtained when chemical fertilizer was used. Also, based on the cost analysis conducted, it was shown that the total cost (fertilizer and labor) for plants grown with vermicompost was lower than plants grown with chemical fertilizer. However, the usage of vermicompost as the single source of nutrients is not suggested for this type of soil and field conditions, but can be used as a supplement to maintain the soil quality and ensure agricultural sustainability.


1977 ◽  
Vol 57 (3) ◽  
pp. 371-374 ◽  
Author(s):  
A. J. MacLEAN

There was no evidence of leaching of K below the 0- to 30-cm layer following addition of a total of 2,232 kg K/ha to a loam and a sandy loam soil in 3-yr field experiments. Grasses contained higher concentrations of K and recovered considerably more of the added K than did corn.


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.


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