Elaheh Daghighi Masouleh

You might want to use 0, 1, 2,4, 8 MT per hectarewith biochar to get a handle on the economic effect which would be most obvious in a crop like potatoes.

An acid sandy soil would be most recommended.

Using a similar strategy of dose have similar experiment with compost.

Use the Cornell University Soil Assessment for measuring the results.

You could perform the experiment in the greenhouse and in the field.

The focus will be the determination of a minimal economic dose to foster economic returns and getting dosage curves.

Dear @Paul Reed Hepperly, I am thankful to receive your worthful answer. I will consider your comments in my project planning.

Soil treatment measures could be both microbial (PGPR) as well as non microbial. Biostimulants also one of alternative.

Thank you @Suresh K Malhotra for your interesting answer.

I agree with Paul Reed on the points raised however, I will like to state that the use of biochar at the recommended rate might not be applicable commercially when sustainability is factored into it but compost can be a more suitable option and provides a base for robust microbial activities along its decomposing strata to deliver a continuum in nutrient/energy supply.

You might want to focus your study on rhizosphere soil over bulk soil to better project the economic viability of the project on a short-term, and long-term.

Soil properties including chemical, biological and biochemical would come handy to draw inferences on the population, count, species and relationship that exists amongst soil mesofauna. This will be critical in determining the equilibrium point for optimal engagement in building soil health whole assessing the variabilities predominant in different environment thus making a case for the need to understand the functionalities of mesofauna within the soil Ecosystem.

Read more about Soil-Microbial-Plant interrelationships to get more insights.

Dear, Elaheh D. Masouleh

It is an interesting study in the unknown world (Mesofauna). Therefore, management in this research study, mixing the two components of biochar and compost with (Mesofauna) is very important. But for a favorable conclusion, this research is a function of time and place. In this regard, the opinion (Suresh K Malhotra) can be correct.

@Oluwatosin Ayobami Ogunsola and @Seyyed Akbar Sadaty thank you for your supportive comments.

Hello, Dr. the recommendations of Paul Reed Hepperly is very good. But, do you not forget to provide the necessary N dose for the doses used, especially of compost, because these doses of compost no satisfy the N needs of the potato and not mineralize properly the organic matter, in sandy soil.

Thank you @Harraq Ahmed for your suggestion.

I think these organisms improve physical qualities of the soil and thereby the chemical quality of the soil.

Thank you @Feto Esimo Berisso for your valuable comments.