Agronomist Andrew McGuire explains why there is not enough manure or compost available – and can never be enough – to replenish soil fertility at a systems level. Studies that show improved outcomes on single farms are not measuring improvement at a systems level.
Returning manure to the soil that produced it can be a sustainable way of restoring soil organic matter. Too often the organic matter of many farms is pushed through the bottleneck of intensive livestock production to be applied just a few farms. Robbing Peter to pay Paul.
Can we produce enough manure to serve as a major source of soil nutrients? Agronomist Andrew McGuire shows the limitations due to entropy make it impossible for manure to make up more than a portion of nutrient replenishment.