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1.
Nitrogenase activity in composting horse bedding and leaves 总被引:1,自引:1,他引:0
To date little or no nitrogen fixation has been found in composting materials. However, some materials have high C:N ratios and thus might be expected to support nitrogen fixation. We examined windrows of composting horse bedding and leaves for nitrogenase activity via acetylene reduction and used carbon monoxide controls to differentiate ethylene evolved by nitrogenase from that evolved by endogenous processes. In both piles temperatures were substantially elevated and partial pressures of oxygen greatly reduced thus indicating vigorous microbial activity. In the horse bedding, there were only low rates of ethylene evolution and little of this was due to nitrogen fixation. In contrast, much higher rates of ethylene evolution were measured in the leaf pile and 94% of this was due to nitrogenase activity. We estimate that the leaf pile fixed approximately 0.062 mg N/g leaves during a 5-week period. 相似文献
2.
Chemical, spectroscopic (IR and NMR), and molecular characteristics of humus extracted from urban waste before and after compositing are reported. The main differences are in the contents of acidic groups and straight aliphatic chains which diminish in the composted material. In comparing humus characteristics of composted urban waste and soils, the only real difference was found in the elution curves on Sephadex G-100, where the ratio of 100,000 and 1,300 peaks was higher in the compost than in the soil curve. The finding suggests that this ratio is a parameter that could enable us, even if in a semiquantitative manner, to follow the humification process of the compost when its addition to the soil is not less than the autochthonous organic matter content.Research work supported by CNR, Italy, Special grant I.P.R.A.-Sub-project 1. Paper N. 1531. 相似文献
3.
Changes in soil structure and in microbial population were recorded in a long term field experiment over the growing season
of maize (June–November). Determinations were made on samples from plots which had received, for two years, the following
treatments: mineral fertilizers, farmyard manure and three rates of compost. Seasonal variations were observed for the stability
of soil aggregates, total porosity, pore size distribution, mycorrhizal infection and aerobic cellulolytic microorganisms.
The stability of the soil aggregates changed in a similar way to that found for both mycorrhizal infection and the number
of aerobic cellulolytic microorganisms. Physical characteristics were not affected in any instance by the organic dressings
and microbiological populations were generally influenced only by the higher doses of compost. 相似文献
4.
Haibin Wang Jianhai Ding Shiwei Liu Xiaochao Bai 《Biocontrol Science and Technology》2019,29(10):924-939
ABSTRACTConsidering the different carbonic source utilisation abilities of microbial species, we used six carbonic supplements to acclimate the microorganisms in two types of compost teas (named CT1 and CT2). The effects of the different carbonic supplements on the physicochemical and biological parameters of the acclimated microbial broth were investigated. The influence of these supplements on the biocontrol effect of the broth against cucumber damping off caused by Pythium aphanidermatum was also assessed. Results showed that treatment with glucose, sucrose, or starch reduced the pH and weakened the biocontrol effect of the acclimated microbial broth. The glucose treatment increased the population size of fungi and yeast. The chitin, cellulose, and wheat straw treatments significantly elevated the pH and electrical conductivity (P?<?0.05), increased the bacterial population size, and positively affected the biocontrol effect of the acclimated microbial broth. The glucose treatment had higher (75.3% and 79.4% for the CT1 and CT2, respectively) whereas the wheat straw treatment had lower (34.6% and 25.6% for the CT1 and CT2, respectively) disease incidence relative to the blank control (85.6%), bacterial population size (r?=?0.64 and 0.69) and number of colony types (r?=?0.82 and 0.76) highly correlated with the biocontrol effect of CT1 and CT2 while the reducing sugar content negatively correlated with the biocontrol effect (r?=??0.57 and ?0.86). 相似文献
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Shikha Verma Anamika Sharma Raj Kumar Charanjit Kaur Anju Arora Raghubir Shah Lata Nain 《Saudi Journal of Biological Sciences》2015,22(3):256-264
Nutrient management practices play a significant role in improving the nutritional quality of tomato. The present study deals with the evaluation of compost prepared using Effective Microorganisms (EM), on antioxidant and defense enzyme activities of Tomato (Lycopersicon esculentum). A field experiment with five treatments (control, chemical fertilizer and EM compost alone and in combination) was conducted in randomized block design. An increment of 31.83% in tomato yield was recorded with the combined use of EM compost and half recommended dose of chemical fertilizers (N50P30K25 + EM compost at the rate of 5 t ha−1). Similarly, fruit quality was improved in terms of lycopene content (35.52%), antioxidant activity (24–63%) and defense enzymes activity (11–54%), in tomatoes in this treatment as compared to the application of recommended dose of fertilizers. Soil microbiological parameters also exhibited an increase of 7–31% in the enzyme activities in this treatment. Significant correlation among fruit quality parameters with soil microbiological activities reveals the positive impact of EM compost which may be adopted as an eco-friendly strategy for production of high quality edible products. 相似文献
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Gabriele Alfano Giuseppe Lustrato Giuseppe Lima Domenico Vitullo Giancarlo Ranalli 《Biological Control》2011,58(3):199-207
Despite its proven agronomic value, the plant disease suppressive effect of composts from olive waste has not been adequately investigated. In the present study, the disease suppressive potential of two olive waste (OW) composts against soil-borne plant pathogens was investigated. Both OW composts showed sizeable, active microbial populations, which were able to grow actively on chitin and cellulose. In plate inhibition trials, OW compost water extracts (CWEs) exerted a significant inhibitory effect on the growth of the pathogens Fusarium oxysporum f.sp. lycopersici (Fol), Pythium ultimum, Phytophtora infestans, Sclerotina sclerotiorum and Verticillium dahliae; and in pot experiments, the OW composts significantly reduced P. ultimum damping-off and Fol wilt diseases on tomato seedlings. The disease suppressive effect of OW composts seems to be due to the combined effects of suppression phenomena caused by the presence of microorganisms competing for both nutrients and space as well as by the activity of specific antagonistic microorganisms. 相似文献
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Francesca ParatiRoberto Altieri Alessandro EspositoArianna Lobianco Milva PepiLorenzo Montesi Tan Nair 《International biodeterioration & biodegradation》2011,65(1):160-163
The production of a substrate containing destoned olive mill solid waste for the cultivation of Agaricus bisporus (Lange) Imbach on an industrial scale was studied. A standard mushroom compost (C) mainly made from straw and poultry manure was compared with the experimental compost (EC) containing the same ingredients as (C) but with added olive mill solid waste (10.6% w/w). Microbial indicators such as counts of heterotrophic microbes and actinomycetes were higher in EC than in C. In addition, compost selectivity as indicated by higher mushroom yield and biological efficiency of EC was higher than that of C. Market quality of the mushrooms produced in both C and EC were comparable. These findings support our work that olive mill solid waste can be used safely in thermal composting process to produce a selective substrate for industrial-scale cultivation of A. bisporus. This study also demonstrates an environmentally sustainable system to manage solid waste from olive oil extraction processes thus overcoming environmental pollution brought about by irrational disposal of the waste on farm lands. 相似文献