When doing experiments the amendments need to produce measurable changes in the properties of interest. What you are citing is a record of just that experience by experts in different fields. .

• It seems like your question is asking whether the amount of biochar used for soil physics and geo-techniques is sustainable for plant growth and economically viable. To answer this, it's important to note that the effectiveness and economic feasibility of biochar applications depend on various factors such as the type of soil, plant species, biochar quality, and intended purpose.
• Research indicates that biochar, when used judiciously and in the right conditions, can enhance soil fertility, improve water retention, and sequester carbon, promoting plant growth. However, excessive use of biochar might alter soil properties adversely, affecting plant health.
• Regarding economic feasibility, the cost-effectiveness of biochar application varies. Factors like biochar production costs, transportation, and application methods influence its economic viability. Economic analyses are essential to determine the feasibility of large-scale biochar applications in agriculture and other fields.
• In summary, the appropriate use of biochar can benefit soil health and plant growth, but its effectiveness and economic viability depend on careful consideration of specific conditions and cost-benefit analyses. Therefore, while biochar holds promise, its application must be tailored to individual contexts to ensure both plant survival and economic feasibility.