• Ysabel Huaccallo asked a question:
    How can I start to design a biodisk reactor, and a composting reactor?

    Hello everybody,

    I am interested about to design differents reactors to treat wastewater so as knowing which calculus I must do. 

    Thanks for advance.


  • Federico Gutiérrez-Miceli added an answer:
    How significant is compost tea as a source of plant nutrients?

    Some research claims that compost tea could improve plant growth and serve as a source of plant nutrients (of course, it depends on how many times you apply the tea per plant cycle). Given the relatively low concentration of most nutrients in the tea and its weak buffering capacity, is this claim valid under realistic growing conditions, especially for fast growing vegetables?

    Federico Gutiérrez-Miceli

    Dear Nguyen Hue, my experience i on vermiwash (VW) or vermicompost tea (VCT) in production and application on some crops such as maize, sorgoum and sugarcane. In these crops VW was insufficient for support plant growth. I enclosed pDF for you reference. Also, is very important to analize microbial composition and changes in physico-chemical properties with respect to storage time.

    + 7 more attachments

  • Annangi Subba Rao added an answer:
    NP fertilizer & compost were applied to a soil, is it feasible to utilize the total N content of the compost to estimate N use efficiency of a crop?

    A factorial combination of four rates of N fertilizer (0, 50, 100, 150 kg N/ha) and three doses of compost (0, 10, 20 t/ha) was evaluated under field condition. The N content of the compost is 1.5%, i.e. (0, 150, 300 kg N/ha). However, according to previous works, only about 10-20% of the total N content of compost may be available to a crop. Thus, is it practically recommended to use the total N content of the compost to estimate the N use efficiency of crops, that is agronomic efficiency (AE) and apparent nutrient recovery efficiency (ANRE).

    Annangi Subba Rao

    Dr.Getachew, If we want to relate the N supply from manure and grain yield,nutrient uptake efficiency by crop,utilization in grain production, we can utilize the samples taken at harvesting stage.The labile pool or active pool  of carbon, hypothesised to persist upto 5 years,on mineralization may supply N for up 5 years also but quantity mineralized may be small.It may depend on amount of manure added,probably the composition and other factors. I have not come across long-term mineralization studies.

  • Sindor Pardaev added an answer:
    Can anyone suggest an easy method for making compost by using only municipal solid waste?

    Does anyone know any method for composting of municipal Solid waste? Can the 100% of the waste prepare good compost? Or does some % mixture of other organic waste need to be added?Do you know about papers related with this issue? Thanks in advance. Regards, SINDOR.

    Sindor Pardaev

    Thanks all for providing the requested information. 

  • Nazir Hussain added an answer:
    Why do we keep 30/1 C: N Ratio for compost preparation? Why not keep 10/1 or 15/1?

    The standard C: N ratio for compost is 25/1 to 35/1.  The energy source for micro organism is carbon while N is a protein source. so why not to increase the N ratio in compost.

    Beside this i have studied that high concentration of N will leach down, will loss in form of ammonia gas and will make a bad smell in compost. so all the are the real fact, but i want a logical phenomena that beside these losses and bad smell is there any proper reason to keep 30/1. is these are the need for microbes to utilize one N for 30 Carbon?.

    Kindly explain me that point. If we look, Plant responded to N so why not to Keep the C: N ratio 10/1.?

    Nazir Hussain

    Good points mentioned by Dr. Abdul Ghafoor.

  • Hannachi Abdelhakim added an answer:
    Can organic recycling significantly meet the potassium needs of crops?

    Potassium is the third most important plant nutrient required in substantial amounts in crop production.Potassium requirement, quantitatively, is equal to or higher than nitrogen in many crops.Cereal straws,organic manures ,composts,wood ashes,industrial byproduct organic wastes contain substantial amounts of K.So,can organic recycling with the above mentioned or other organic sources  meet substantial K requirement of crops and increase the crop production?

    Hannachi Abdelhakim

    Not directly but by the interaction between the soil solution and the exchange complex.

  • Karamjeet Kaur added an answer:
    What are the methods of preparation of Compost of Rice Straw by Lignocellulolytic bacteria?

    Actually i want to prepare rice straw compost by lignocellulolytic bacteria,so i want to clear one thing that is it important to add  cattle manure and also can we estimate the degradation capability of cellulose,lignin and xylan .And can we determine the C:N of the compost prepared without  cattle manure.

    Karamjeet Kaur

    Preparing a good compost of rice straw is not easier. You can add cattle dung to fasten the process of composting. You can easily determine the change in lignin, cellulose and sugar content over a period of time by following standard methods of AOAC or NREL. C and N content of any substrate can be determined and addition of cattle dung has nothing to do with it. But yes, addition of cattle dung does help in maintaining an appropriate C:N ratio which is essential for composting.  

  • Sobur Ahmed asked a question:
    Would you please mention the chemical compostion of Hides/ Skins mentioning latest reference?

    I'm looking for the protein content in raw hides and skins with the reference article/ books

  • Jutta Gutberlet added an answer:
    Does substituting industrial fertilizer with organic compost reduce human interferences in the global phosphor and nitrogen cycle?

    Cities collecting and composting organic household waste for urban agriculture reduce the need for industrial fertilizer. Thus the use of compost cuts out the impacts from industrial fertilizers and the production of these fertilizers.

    Jutta Gutberlet

    Thank you for all of your valuable responses which confirm my own understanding of the importance and gains from recovering organic waste. Of course, it is not enough to just recover the organic part of household waste. You are right that wastes produced by humans need to be tackled (reduced or recycled). My research is primarily on resource recovery in developing countries. Unfortunately in many countries in the global south most of the organic household waste is still landfilled. However, change is coming. It is becoming very expensive for governments to maintain landfills and there is more interest in different forms of waste recovery. Here, collecting organic waste for compost or energy production creates many jobs, which is yet another concern in these economies.

    My overall concerns are embedded in global environmental concerns. Reducing human interferences in the global phosphor and nitrogen cycle are key challenges. So it is correct to say that organic household waste recovery makes a small contribution to that reduction.

  • Annangi Subba Rao added an answer:
    How can we properly define organic manure?

    By Dictionary meaning manure is animal excreta usually with straw,used to fertilize land..The Thesaurus gives slightly elaborate definition-any animal or plant material used to fertilize land especially animal excreta usually with litter material.There is no mention of rotting or composting in the definition.The compost is the decomposed remnants of organic material,usually plant origin but may include animal dung.Main concern is fresh dung may contain weed seeds and pathogens.Some manures like farm(yard) manure ,cattle dung, with straw/bedding material are subjected varying periods of rotting.Some excreta/droppings of sheep or goat are simply dried and applied. Poultry manure   may be with or with out litter, composted or simply dried.While manure is differently handled, composting is done under controlled conditions and the product is well defined.But manure definition doe not specify that it should be composted.So how to define manure appropriately for use in agriculture and quality control?

    Annangi Subba Rao

    I hop and wish that the condition of composting  is imposed on   all bulky and dung based manures for safer use of manures and quality control.I thank all the participants of the discussion.

  • George N.K. Rockson added an answer:
    Does anyone know of any relationship (as a regression) for the determination of Total Nitrogen (Compost) vs Organic matter as a parameter?

    Dear All, does any one know of any relationship (as a regression) for the determination of Total Nitrogen(Compost) vrs Organic matter as a parameter?

    George N.K. Rockson

    Thanks all,

    I have done some work an i realized a combination of about five physio-chemical parameters including the temperature transforms.

  • Federico Gutiérrez-Miceli added an answer:
    Can we make a compost from the biomass of Lantana or Chromolaena for use in field crops ? Allelopathic or Beneficial ?

    Physiology and Productivity.

    Federico Gutiérrez-Miceli

    Hussain et al in a recent publication report what vermicomposting detoxifies lantana cámara. Journal of Hazardous Materials 298 (2015) 46-57

  • Nazir Hussain added an answer:
    How do I identify the characteristics of vermicompost ?

    What are the criteria by which we can identify a vermicompost?

    What lab tests should be made to a material in order to obtain that it is a vermicompost and not just regular compost ?

    How can we identify and characteristics vermicompost or can we identify the vermicompost at all?

    Nazir Hussain

    Yes, Imran your views I endorse.

  • Virginia Isabelle added an answer:
    What are the methods used in determining the C:N ratio of composting materials and composts?

    C:N ratio of materials need to be determined before and after the composting process. 

    Virginia Isabelle

    Thank you Mr. Jean Pierre Paul. That's actually what we are doing. We are trying to optimize the process of composting with earthworms so the resulting composts will have consistent quality. However, I am inexperienced in this field, so I'm trying to look in all corners. 

  • Anoop Kumar Srivastava added an answer:
    Can we make a good compost out of dried/dead perennial trees?

    In areas where commercially perennial crops like citrus , mango , guava, litchi, sapota etc are grown , good number of trees either decline so early or attain an unproductive age , which are eventually cut and dumped.In the process , they are simply heaped around well grown- up orchards, which again is not a  hygienic practice.  The biggest question is how see them off , especially when their number is so large. Their C:N ratio comes out to be somewhere 500-700:1. And to get a compost of C:N ratio of  25-30: 1, if these woody plants are shredded into small pieces mixed with some fresh dung as source of microbial inoculum and add some fresh soil into it , preferably in  2:1:1ratio , can we expect some kind of compost ?. And , if so  , any guess , how many days will it take to deliver a compost of C:N ratio of 25-30:1. 

    Anoop Kumar Srivastava

    Thank you Mariangela. Can you  elaborate   further on your response . It is very interesting .

  • Bhavin Mehta added an answer:
    Are all Alternaria species plant pathogenic in nature ?

    I have a few Alternaria with excellent composting properties, can they be used safely ?

    Bhavin Mehta

    Most of the Alternaria are found pathogenic but appropriate method like detached leaf technique has to be utilized because Alternaria species are producing toxin which is host specific so they might not be pathogenic to other hosts so one must have to test it.t

  • Annangi Subba Rao added an answer:
    What is the beneficial role of solid or liquid form of humic acids application to soil or plant?

    Currently several humus acids based formulations including manure /compost extracts and often chelated with micronutreints are being used/recommended for use in crop production.In what way or by which mechanism these humic acids aid in plant nutrition.Whether the  humic acids absorbed through root or leaf have some beneficial role in plant nutrition?

    Annangi Subba Rao

    I thank all of you for your. responses

  • Philip Barlow added an answer:
    Is there a typical conversion value for Composted Green waste to Humus?

    I understand that there is no exact answer to this question because there are many variables involved and the term "Humus" is not exact either. However a ball park figure would help.

    Philip Barlow

    Thank you for your helpful replies 

  • Michael Quintern added an answer:
    Any advice about a decrease in macro nutrient content after vermicomposting?


    I recently ran an experiment for 10 weeks to analyse the benefits of vermicomposting. The feedstock consisted of ground coffee with mixed salads from supermarkets being substituted as the kitchen waste. After about 7 weeks, few of the earthworms began to die. I also noticed growth of ants within the reactor. An analysis in week 10 has shown the reactor has shown the feedstock has a higher nutrient content than the reactor which had the compost?. 

    Any ideas on how this is possible?

    Michael Quintern

    Hi Jason,

    Vermicomposting is a complex ecoystem - even in 'simple' trials such as yours, considering only two waste streams / organic resources. I often find it more even more difficulty to be limited to only two resources as the optimum ratio of the two resources may not be the optimum for successful vermicomposting. Understanding that vermicomposting can have different desired outcomes, depending on what your primarily goal is, e.g. organic waste reduction at lowest costs, best quality vermicast, minimum effect on the environment during vermicomposting, or a focus on breeding earthworms.

    All colleagues above mentioned potential or most likely reasons for not meeting your desired outcome, which I asume from your introduction is vermicomposting for  concentration of nutrient content in the solid product. We all know that parameters  such as pH, moisture (too wet or dry) C/N ratio, structure, oxygen supply, and there will be few more to consider, will effect your outcome. We all could advise you in more detail if you would share a few more details. You mentioned some analysis you have conducted already. Maybe you can provide pH, moisture content, C/N ratio, mixing ratio, nutrient content etc. Do you have produced any leachate in your reactors? Have you analyzed it and calculated the nutrient budget in the solid and liquid fraction? Did you loose any e.g. N? Nitrogen and potassium are washed out easily.

    I would like to encourage you to carry on with your trial - understanding why a system is not working is the key to find the successful system. You will find that some combinations of organic resources will not work in the lab (small reactors), but will  succeed at large scale in the field. As well you will find that successful trials at small scale do not work in the field at full scale. For example I can force compost worms to feed on certain organic wastes if they can't escape the reactor. Once there are no borders, the worms will just leave or stay out of your mix and search for better feedstock sources.

    The total nutrient content of the vermicast might be seen as the most important aspect for marketing, as this is number you can easily put a value to, when comparing with mineral fertilizer prices. The true market value - at least here in New Zealand - is in the humus and the biological functions of the vermicast. We are marketing close to 50,000 tonnes of various vermicast products this year and often customers prefer the vermicast with a wider C/N ratio and lower total N content of 1% over the nutrient-richer vermicast with a nitrogen content of close to 2%.

    I am looking forward to some more details from you to help solving your 'mystery'.

    Keep up your interesting vermicomposting research.

    Warm regards,


  • Roland Ramusch added an answer:
    Can anyone recommend some case studies of decentralized composting initiatives carried out in developing countries?

    I am looking for research paper or person who can help me provide information . .am especially looking for information on Scientific Handling of Waste Society, Bangalore India and other similar activities in developing countries? Will appreciate your kind support..

    Roland Ramusch

    Linzner R. (2010): Decentralised composting of market waste and use in urban agriculture; Conakry, Guinea. Urban Agriculture Magazine, 23 (April 2010), 20-21; ISSN 1571-6244.

    Educational movie on decentralised composting based on a small-scale facility located in Conakry (Guinée):

    Project report:

  • M.Azizul Moqsud added an answer:
    Can anybody please explain to me how one can estimate the C/N ratio if you're producing an organic compost?

    Hi all, 

    I want to know how to estimate the amount of the organic products (like vegetable scraps, sawdust, ripen fruits) you are putting together for the production of organic compost that can maintain perfect C/N ratio? We are following Berkeley's 'The Rapid Composting Method'. (Please see the attached document) 

    Thanks in advance

  • Alan P Newman added an answer:
    How do bulking agents like beanstalk and sawdust help compost eco-toilet content?


    I am planning to do research on eco-toilet and possibility of (co)composting with other waste materials like saw dust, and solid waste. While doing literatures search, I came across two publications relevant to my proposed research: "On-Site Operation of a Composting-Type Eco-Toilet Using Beanstalk and Sawdust as Matrix by Liu, N. et al. (2012), and "Processing of Human Feces Using Beanstalk and Sawdust as Matrix in a Composting-Type Eco-Toilet" by Liu et al. (2012) both published in Advanced Materials Research (Editors Jingtao Han, Zhengyi Jiang and Sihai Jiao). Can anyone forward me these articles? The link (attached below) gives the article information.

    Thank you 


    Alan P Newman


    Sorry I should have read the question more closely.

    I do not have these papers and it is a long time since I was involved in this. I seem to remember that your  country's EPA did some work on this. Perhaps someone at the EPA will be able to help you.

    Good luck 


  • Rebecca Last added an answer:
    The vermicompost created out of grasses have seeds that normally become weeds in one';s garden. How can this seeds be controlled organically?

    for people who would love to grow vegetables organically, how can they overcome the processes of getting rid of weed seed before they prepare their vermicompost?

    Rebecca Last

    Heat treatment can indeed be effective in neutralizing weed seeds, but this requires sustained high temperatures, which would likely harm or kill the worms. A couple of other possible controls are: (1) try to cut the grasses before they go to seed; and (2) applications of corn gluten meal are now used widely in Ontario to prevent emergence (i.e., germination) of annual weeds. In the latter case, timing of the application is key because if applied after germination has occured, the corn gluten meal is also an effective fertilizer! It does not work on perennial weeds, either.

  • B.R. Rajeswara Rao added an answer:
    How can a contamination assessment of compost be made through bioindicator plants?

    There is a great potential for reducing the municipal and industrial wastes through composting. Many phytotoxins come from agricultural use of pesticides and industrial solvents. How the effect of these phytotoxins can be studied using the plants as bio-indicators to access the phytotoxicity level of these composts? Please, suggest some related articles and research proposals.

    B.R. Rajeswara Rao

    Check the following documents for their utility:

    + 2 more attachments

  • Dervilla Mcgowan added an answer:
    What is the best way to enumerate microorganims in a compost sample?

    I want to have a look at bacterial and fungal numbers in compost. I have never worked with soil microbes before, only biomedical bacterial organisms so would love detail useful for a novice.

    Thank you in advance!

    Dervilla Mcgowan

    Thank you so much for you r answers. It seems its pretty much the same as the methods I have used before which is great. I really appreciate the feedback.

    Thank you

  • Manfred Fehr added an answer:
    Does any city in a developing country have in place functional reverse logistics for biodegradable municipal waste?

    Although biodegradable material represents 70% of municipal waste in developing countries, I do not know of any city that runs separate collection and composting facilities. I am looking for a precedent to imitate.

    Manfred Fehr

    Dear Md, Nirmala and SP,

    Thank you kindly for your input. It is very helpful in my research.


  • Nidal Shaban added an answer:
    Does water extract from compost (compost tea) increase plant growth and suppress diseases?

    One of cultural practices in organic farming is to spray vegetable crops with compost tea. It is believed that compost tea would provide plant nutrients, stimulate growth (via growth hormones in the tea), and suppress diseases. How strong is such evidence?

    Nidal Shaban


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