The costs of soil restoration
I recently did a calculation on the costs of restoring soils.
One acre of soil is 43,560 square feet. At a minimum, we are interested in the top 6" or 1/2 foot, so that results in a volume of 21,780 cubic feet.
The vast majority of our industrial agricultural soils are now at 0.5% organic matter, the point at which they are no longer productive without massive inputs of salt-based fertilizers. To get those soils functional, we need to bring them to about 3% organic matter and balance the minerals. Thus we need to increase the soil organic matter by 2.5%. Let's assume that we can replace that organic matter with compost alone (i.e. none of the expensive minerals). Fortunately, compost contains some of those minerals -- however, compost alone cannot fully balance the mineral needs for optimal plant growth.
Two-and-a-half percent of 21,780 cubic feet comes to 545 cubic feet/acre or 20 cubic yards. In bulk, we can source poor-to-average quality composts at $30/cubic yard delivered to the farm. That results in a cost of $600 per acre for the compost alone, for one acre. That does not include the costs of applying the compost (machinery and time) and incorporating it into the soil (more machinery and time), nor the costs of preventing its future loss to the same erosion that allowed the original soil to wash away into the Gulf of Mexico in the first place.
For a 100-acre farm, the cost of compost alone would be $60 thousand dollars. The value of very good corn land is around $10,000/acre; but for much agricultural land, the ceiling hovers closer to $3,000 per acre. Clearly no financial institution will loan a farmer $600 per acre for soil restoration when its resale value is only around $3,000 - $10,000/acre.
Based on a series of 40 soil samples that we submitted from 40 Travis County soils, we found that restoring the mineral balance in a soil is quite expensive. Restoring simple minerals like Sulfur and Phosphorous, etc. would add upto about $2,500/acre. More complicated problems such as balancing out excessive Magnesium by balancing out the remaining minerals would add on additional $5,000 per acre. Ecologically advanced soils with high humate levels (old carbon) would cost another $10,000. That adds upto about $20,000 per acre when all totaled.
No one ever explained to my father, a farmer in southern Ontario, that the combined cost to restore his soils would add up to about $20,000 per acre. If that was the going to be the case, would he have proceeded? Thankfully for my family, everyone in farming was convinced to follow the green revolution, and so all soils lost economic value as a level playing field. Thus when we went to sell our farm, our land was valued the same as everyone else's.
Further, how is a farmer to recoup this investment? Do we value the food coming from these soils enough to double the revenue/acre of the farm? Recall that I did not include the cost of balancing the minerals for the farm. Those numbers can vary quite widely, and the cost of minerals can add up to another $10,000/acre. Is that important? Yes, because balancing the soil minerals and increasing soil organic matter is the only way to get the nutrient-dense forms of food that we so desperately need to start controlling the skyrocketing costs of our health care.
This is what I call a soil economics problem. We have dedicated our lives to finding solutions to these problems, because our future and that of our children depends on it.
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NOTE: I will have to made some additions to this yet, regarding the costs of minerals and water. Done. New paragraph based on MEF15 Residential Soil Problem 1-12