I think unsterilized is better because the results is more likely to real condition which farmers intend to do. another suggestion is using both sterilized and unsterilized if you can handle it and compare their results specially for farmers.

I agree with Pezhman Allahmoradi : If you sterilize you soil, you won't be able to give any conclusion about a natural soil.

Moreover, depending on the method you use to sterilizeit, you'll change its physico-chemical properties (except with ionization apparently, but it is quite expensive).

Still, if you use this latter technic to sterilize your soil, it can be interesting to have some sterilized replicates to have a vision of the effect of the global soil biodiversity effect on the parameter you are studying. Otherwise, you won't need it.

Maybe you can just change your perception of your biased results due to indigenous microorganisms. I prefer to see that as interactions between communities and species, which are essential to try to assess what's happening in soils, eventhough it is more complicated :).

It depends on your resaerch question whether you should use sterilized or unsterilized soil. Are you interested in the effect of the fertilizer on nutrient status of soil, plant growth etc? Then you should definitely work with unsterilized soil. Biofertilizer sounds like you are using some kind of organic material? The effect of such substrates is inevitably linked to the microbial activity in soil.

Dear Antoine,

the most important think to consider when doing any research is the beneficiaries or stakeholders of the research output. and how they relate with the sample you are analysing. You are right to say farmers don't treat or sterilised their soil. For you research output to be adopted and feasible, you should do it as farmers are using it. and Micro organisms are present in a living soil which is also classified as good or organic or natural. Therefore see the biasness as the degree of fertility of the natural soil since soil without micro-organism are dead and i believe and know dead soils are not what farmers produce thrives in.

First, the efficiency should be checked under sterile conditions because only the inculated biofertilizers will be present. After the best treatments are selected, the best treatments have to be checked again under unsterile conditions.

if you target is for farmers. i would go for unsterilized soil , which will provide a normal conditions as for the farmers. thus your results will portray actual effect on real situation . but if your target is on the effect of the bio fertilizer alone you go for the sterilized soil .

Your question focuses on the difference between science and technology. The answer is both. Sterilized soil removes variables and allows you to test the hypothesis or concept in a reproducible manner. Unsterilized soil allows you to determine if the technology has value in application.

When soil is sterilized it creates a biological vacuum and changes the nutrients and their availability. For tests in green houses steamed soil is not a sterilization but more like a pasteurization. For your studies the sterilization and pasteurization may be useful but ultimately practical application requires that the introduced microbes need to competitive competence to maintain themselves in soil environments which can be hostile to introduced microbes. If you make an experiment with your different options the results can convince you of pros and cons under you particular environment.

I think unsterilized is better because the results is more likely to real condition which farmers intend to do

Soil sterilization is usually done when you have soil-borne disease problem that will cause damage to your plants. But even if the soil has soil-borne disease pathogens and the plant that you will use is not affected by the disease, then there no need to sterilize.