Biochar costs vary widely. Since biochar is typically priced by volume, keep in mind that 1 cubic yard is about 200 dry pounds. A cubic meter of biochar is about 110 dry kg.

A 2014 survey by the International Biochar Initiative found the average wholesale price among 28 U.S. producers was $0.68/lb ($1360/ton), while the average retail price was $1.94/lb ($3872 per ton).

In metric units, these equate to $1.50/kg ($1500/metric ton) for wholesale and $4.26/kg ($4260/metric ton) for retail.

S. Jirka and T. Tomlinson (2015), '2014 State of the Biochar Industry: A Survey of Commercial Activity in the Biochar Sector', International Biochar Initiative report. (http://www.biochar-international.org/node/8367)

Default fertilizer prices shown here are average U.S. prices for 2008-2013. Note that prices are reported here by nutrient mass, rather than fertilizer mass.

Default irrigation prices reflect average costs of off-farm water. In 2013, average cost by state was: ID = $17.65, WA = $32.01, OR = $20.18 per acre-foot.

USDA Economic Research Service (2013) 'Agricultural Prices', Table 7. Average U.S. farm prices of selected fertilizers. (https://www.ers.usda.gov/data-products/fertilizer-use-and-price/)

USDA Economic Research Service (2017) 'Irrigated Agriculture in the United States', Table 3-13.(https://www.ers.usda.gov/data-products/irrigated-agriculture-in-the-united-states/)

Biochar may initially tie-up nitrogen, increasing nitrogen fertilizer requirement.

Biochar can be a source for P, K, S, Mg, and Ca, and may act as a liming agent. Use the Biochar Selection Tool to determine your crop's nutrient and lime requirements and amounts provided by different biochars.

Also use the Biochar Selection Tool to see if biochar may increase or decrease water retention in your soil.

In economics, the value of future income is often discounted to represent the idea that a dollar earned today is worth more than a dollar earned tomorrow. This is because money earned today could be invested to generate interest and additional income over time.

Future income is discounted by the interest rate you could expect to earn if you were to receive that income today and invest it in stocks, bonds, or some other venture. The interest rate is used to calculate the 'net present value' of future income.

The stock market has a return of about 7%, but a common estimate of 'risk-free' interest rate is only 2%, based on the interest rate on a 10-year Treasury Inflation Protected Security (TIPS).

For natural resource investments, an important consideration is that a lack of investment today may actually result in degradation of the natural system. Very low or even negative interest rates may be applied to account for this perspective.