Good question Indranil. I do not think , there is any such standards worked out for quality assessment of manures based on nutrient composition , except the basic parameters based on which the quality of a manure is to be assessed. Find below the pertinent PDF for further reading .

I agree with you both, but we have to find out some solution as to address this particular situation. As you know most of manures produced by the farmers are not tested, however they generally do not use any inorganic fertilisers. When coming to the commercial organic manure producers, it is a malpractice to increase nutrient content through inorganic fertiliser prior to quality testing. Though these are not enriched compost which technically require inorganic fertilisers for decomposition/enrichment etc. What I feel there should be thumb rule for C:N, C:P ratio for each manure (some manures have this according to FCO) so that it can be compared with the sampled fertiliser materials etc. Though this is crude method.

Yes , i agree with you Indranil. We need to have  manure quality standards in terms of so many paramters like C:N /C:P ratio , CEC, respiration rate , CEC/total organic carbon ratio , humification index, lignin/cellulose ratio, water soluble carbohydrates etc . These are often used in defining the maturity standards of a compost /manure  .We keep saying , there has to criteria for minimum  microbial of a manure or compost . Likewise , nutrient concentration could also be defined. 

Yes I absolutely agree with you Dr. Srivastava.

Apart from addition of chemicals to increase content of specific nutrients, many of the marketed organic manures also contain substantial amount of heavy metals viz, Cd, Pb, Cr and even Hg along... Use of city garbage in the manufacture of organic manures is the probable source of these metals....

Yes exactly, Prof. Patra. But they can be tested through acid digest followed by estimation in AAS. These parameters are also included as the quality criteria of manures in FCO.

This is why you need to get a good representative composite sample. When you sample manure for nutrient content, make sure that you get samples from several places from the heap, then composite them and take a good representative subsample. C and N concentrations can be determined from a C and N  analyzer (LECO, ELEMENTAR, etc). For other nutrients, you may have extract with acetic acid and then determine with atomic absorption, flame ionizer, spectroscopic method. etc.

I agree the answers of scientists given above that there is no known std method for mixing synthetic fertilizers with manures. It has to be site-specific.

I have not raised the question for mixing synthetic fertiliser in organic manure. I am concerned about the adulteration in organic manures by the producer.

The quality of organic manures is a great concern.The Ministry of Agriculture and Cooperation,Govt.of India ,Bureau of Indian Standards( BIS) are addressing the issue by fixing a quality criteria for different manures and composts like municipal solid waste compost ,phospho-compost etc.By simply adding some fertilizer nutrients to manures one can not attain all the quality criteria fixed for a particular manure/compost.In a compost like MSW compost,attaining certain desired level of carbon,C:N ratio,reducing the level of inert material(from around 30% to 10%)and heavy metal content is very difficult.For example ,in case of compost and phosphocompost with total carbon content of 23.9% and 20.8% and total N of 0.9% and 1.0% respectively, the C:N ratios would be 26.5 and 20.4.In case of MSW compost the total organic carbon was 11.3% and N%0.63 and the corresponding C:N ratio was 16.4.It means that with low carbon and N one can achieve nearer to ideal C:N ratio.In MSW compost the prescribed total carbon content was 12% and total N%0.8.With a little addition of carbon and N one can meet the standard values.By sorting/segregation. the MSW material one can increase both the total C and N and the C:N ratio in the compost.Even the heavy metal contents in manure can be brought down by sorting/segregating the waste.The scientists of IISS,Bhopal have developed a classification system for MSW composts based on the nutritive/fertilizing value  and clean index(based on heavy metal content).The different classes of manures shall be marketed for different purposes like agriculture,horticulture or for ornamental plants

.Saha JK  et al( 2010)An assessment of municipal solid waste compost quality produced in different cities of India in the perspective of developing quality control indices.Waste Manag. 30:192-201.

Prof. Subba Rao, I agree with your thought. You will find quality criteria of different organic manures in Fertiliser Control Order 2011 onwards.Here you will find specific percentage of Total Carbon and Nitrogen, Phosphate. Then to determine C:N ratio. Producers are generally concerned about increasing N, P2O5 and K2O % in manures so they often adulterate it with synthetic fertilisers, hereby ignoring the possibility of C: N ratio.

Dr.Das,I understand your concern for quality of manure/composts.In the quality criteria given by FCO 2011 reasonable limits for minimum amounts of carbon and nutrients are given.The challenge in MSW compost preparation is attaining certain level of carbon in the material and reducing the quantity of inert material.It is possible to achieve  the twin objectives through segregation of waste before composting.The other possibility is fortifying the MSW with green waste generated in the city through pruning of trees  ,shrubs or flower, fruit and vegetable waste etc.The compost generated can be used in the city itself for use in gardens,parks and trees/ shrubs on road side.The classification system developed  for MSW compost by ICAR-IISS,Bhopal can be used.

I agree with you Dr Das . This is a very pertinent issue , and unfortunately , we do not have many riders to judge , whether or not,  quality of the  manure is naturally derived or manipulated through some additions, It will highly appreciative of our colleagues , if any one can share about  any possible diagnostic test(s) to judge,  either the nutrient value  or the microbial load of the manure ?

Guess the EU is best regulated on this matter, far beyond the imagination of scientists outside the EU: have fun with reading :

http://eur-lex.europa.eu/GGTSPU-styx2.jki.bund.de-3309-4785654-HnF6gyTU1kToRf5S-DAT/LexUriServ/LexUriServ.do?uri=CONSLEG:2003R2003:20110309:EN:PDF

!!!!

Dr,Schnug,I could not open the attached file and read. Can you help?

Dr.Schnug Please resend the file so that we can go through it.

Ms.Debjani,it is difficult or not possible (with the infrastructure we have) to handle isotopes in Fertilizer Quality Control Laboratories.It should be like our 8 or 10 class cation and anion identification in a given salt by quality tests.

I was expecting such type of answer from you Debjani, indeed this is ultimate way ou t but have you consider our infrastructure. Is it really feasible for us to analyze this. That's why we are discussing about low cost, feasible experimentation either direct or indirect way.

Thanks to all for very interesting discussion with useful inputs. The issue is important and timely. There is no answer to the question with us. But, it has been observed for last few years that mixing of chemical fertilizers changes the physical appearance of the manure. We have not evaluated parameters, but the colour appears lighter and the manure loses uniformity (forms small and medium soft lumps). Standardizing methods for physical parameters may be cost effective and simple.

Dr .Borah,good point.One can characterize and standardize the  easily distinguishable physical parameters of good and adulterated manures.As you are aware the manures have both organic constituents(say different  organic fractions of N , P and S and inorganic constituents (mainly different  soluble nutrient ions of N,P,K and S).So one can estimate the proportion of  nutrients in  organic and inorganic forms in different manures.In normal manures , relatively more amounts of nutrients may be in organic constituents(especially for N, P and S) which will subsequently mineralize when applied to field under favorable temperature and moisture conditions.The inorganic mineral form may be relatively small and fixed (with some variation) for a particular manure(for N,P ,K and S). The proportion of very high mineral nutrients indicate the adulteration of manure.So one has to work out the proportion of the macronutrients in organic and inorganic form and fix certain  mean/standard deviations for common manures.Much deviation in mean values of inorganic component may indicate the level of adulteration.Inorganic mineral nutrients can be estimated  by water/dilute acid extraction and organically -held nutrients after di or triacid extraction.I solicit your opinions on problems with this  approach.

Prof. Rao, I would like to know how to proportionate organic and inorganic fraction from these manures. Do you think most of the inorganic forms become soluble in water : in case of phosphate and micro nutrients- chelation with organic matter may take place. In such case inorganic proportion may not be actual.

That may be a good proposition - semi-quantitative estimation of the readily water soluble forms. Good idea Dr Das. The filtrate may be tested with respective solution for colour development as is done for rapid plant tissue testing. Observation basis simple trial may be done, Would like to know reactions from experts.

I have suggestion in addition to water solutble forms. We can use 60% ethanol to extract water soluble plus other non water soluble inorganic forms. And see if there is any difference. Then we can destroy organic matter by using H2SO4 plus H2O2, followed by digestion to find total form. Subtracting total form to the earlier one we can idea of organic form. I guess.

Dr,Das and Dr.Borah,I appreciate your good comments.To extract the manure 'teas',research workers used water as extractant. To extract inorganic fraction from organic component,workers also used dilute acids(1M HCl).As suggested by Dr.Das water - ethanol mixture can also be tried. Dr .Das one need not worry for complexed P as 75% of P in manures is water soluble(as per USA or European studies).I think in our conditions, both total P and water soluble P may be less  compared to manures in those countries.Almost 100% of K is also water soluble.For extracting water soluble nutrients, 0.01M CaCl2 can also be used/tried.One can try these extractants discussed above to extract nutrients (at least macro) in some common manures/composts.

Yes. This is an important issue. In many forums i have come across urea adulterated vermicompost which is hindering the basic purpose of organic farming.