Effect of Douglas-Fir Sawdust Mulches and Incorporations on Soil Microbial Activities and Plant Growth

1957 ◽  
Vol 21 (1) ◽  
pp. 35-41 ◽  
Author(s):  
W. B. Bollen ◽  
K. C. Lu
Author(s):  
Jehan Khalil ◽  
Hasan Habib ◽  
Michael Alabboud ◽  
Safwan Mohammed

AbstractOlive mill wastewater is one of the environmental problems in semiarid regions. The main goals of this study were to investigate the impacts of different olive mill wastewater levels on durum wheat (Triticum aestivum var. Douma1) production and soil microbial activities (i.e., bacteria and fungi). A pot experiment was conducted during the growing seasons 2015/2017 to evaluate the effect of three levels of olive mill wastewater on both growth and productivity attributes of wheat. Vertisol soil samples were collected from southern Syria. Two months before wheat cultivation, three levels of olive mill wastewater: T5 (5 L/m 2), T10 (10 L/m2) and T15 (15 L/m 2) were added to pots filled with the collected soil samples. Also, a control (T0) free of olive mill wastewater was considered as a reference. Results showed a significant increase (p < 0.05) in germination rate (%), plant height (cm), ear length (cm), kernels number, kernels weight per ear (g) and grain yield (g/m2) compared to control. However, T5 treatment did not induce a significant increase in terms of ear length, kernels weight per ear or yield (in the second season). On the other hand, T10 treatment had recorded the best results compared with the other two treatments (T5, T15). Similarly, the results showed a significant increase in the number of bacterial and fungi cells by increasing olive mill wastewater concentration. This research provides promising results toward using olive mill wastewater in an eco-friendly way under Syrian conditions.


Author(s):  
L. M. Manici ◽  
F. Caputo ◽  
G. A. Cappelli ◽  
E. Ceotto

Abstract Soil suppressiveness which is the natural ability of soil to support optimal plant growth and health is the resultant of multiple soil microbial components; which implies many difficulties when estimating this soil condition. Microbial benefits for plant health from repeated digestate applications were assessed in three experimental sites surrounding anaerobic biogas plants in an intensively cultivated area of northern Italy. A 2-yr trial was performed in 2017 and 2018 by performing an in-pot plant growth assay, using soil samples taken from two fields for each experimental site, of which one had been repeatedly amended with anaerobic biogas digestate and the other had not. These fields were similar in management and crop sequences (maize was the recurrent crop) for the last 10 yr. Plant growth response in the bioassay was expressed as plant biomass production, root colonization frequency by soil-borne fungi were estimated to evaluate the impact of soil-borne pathogens on plant growth, abundance of Pseudomonas and actinomycetes populations in rhizosphere were estimated as beneficial soil microbial indicators. Repeated soil amendment with digestate increased significantly soil capacity to support plant biomass production as compared to unamended control in both the years. Findings supported evidence that this increase was principally attributable to a higher natural ability of digestate-amended soils to reduce root infection by saprophytic soil-borne pathogens whose inoculum was increased by the recurrent maize cultivation. Pseudomonas and actinomycetes were always more abundant in digestate-amended soils suggesting that both these large bacterial groups were involved in the increase of their natural capacity to control soil-borne pathogens (soil suppressiveness).


2012 ◽  
Vol 47 (6) ◽  
pp. 854-862 ◽  
Author(s):  
Irenus A. Tazisong ◽  
Zachary N. Senwo ◽  
Miranda I. Williams

Author(s):  
Aditi Sengupta ◽  
Priyanka Kushwaha ◽  
Antonia Jim ◽  
Peter A. Troch ◽  
Raina Maier

The plant-microbe-soil nexus is critical in maintaining biogeochemical balance of the biosphere. However, soil loss and land degradation are occurring at alarmingly high rates, with soil loss exceeding soil formation rates. This necessitates evaluating marginal soils for their capacity to support and sustain plant growth. In a greenhouse study, we evaluated the capacity of marginal incipient basaltic parent material to support native plant growth, and the associated variation in soil microbial community dynamics. Three plant species, native to the Southwestern Arizona-Sonora region were tested with three soil treatments including basaltic parent material, parent material amended with 20% compost, and potting soil. The parent material with and without compost supported germination and growth of all the plant species, though germination was lower than the potting soil. A 16S rRNA amplicon sequencing approach showed Proteobacteria to be the most abundant phyla in both parent material and potting soil, followed by Actinobacteria. Microbial community composition had strong correlations with soil characteristics but not plant attributes within a given soil material. Predictive functional potential capacity of the communities revealed chemoheterotrophy as the most abundant metabolism within the parent material, while photoheterotrophy and anoxygenic photoautotrophy were prevalent in the potting soil. These results show that marginal incipient basaltic soil has the ability to support native plant species growth, and non-linear associations may exist between plant-marginal soil-microbial interactions.


2015 ◽  
Vol 7 (2) ◽  
pp. 1021-1028
Author(s):  
Jatinder Kaur ◽  
Sandeep Sharma ◽  
Hargopal Singh

Changes in soil microbial activities were investigated to examine the effect of aerobically digested sewage sludge (SS) and compared with compost under incubation conditions over 63 days. Sandy soil was amended with 0.25, 0.5, 1.0 and 1.5 % w/w of compost and sewage sludge. Enzyme activity (dehydrogenase, alkaline phosphatase, acid phosphatase, phytase and urease) were examined at an interval of 3, 7, 14, 21, 28, 42 and 63 days. At the end of the experiment the change in organic carbon, nitrogen, potassium and phosphorus was also recorded.Results indicated that enzyme activities were substantially enhanced in presence of both amendments for first few days and the higher increases were measured at 1.5% of compost and sewage sludge amendment. Then an overall decrease in enzyme activity was recorded. Both the amendments also significantly increased the organic carbon, nitrogen and potassium of the soil while increase in available phosphorus was only recorded in treatment receiving compost. The present experiment indicated that addition of compost and sewage sludge have positive effect on soil microbial activity and can be safely used as soil amendment without having any adverse effect. Though, a previous examination of sewage sludge to be used must be made for heavy metals and pathogens.


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