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.
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.
NutrientStar, which assesses fertilizer management products and tools using field trials and in-depth scientific reviews, was a game changer for farmers. Prior to the launch of the program last year, there was no expert review program to help farmers determine what tools would work as advertised.
The only downside of the program was its limited utility. Farmers had no easy way to extrapolate results from the relatively few number of field trials performed thus far to their own locations. Now, a new geospatial feature called the Technology Extrapolation Domain (TED) framework will make NutrientStar accessible to tens of thousands of additional farmers across the Corn Belt.
I like to think of it as NutrientStar on steroids.
Farmers around the world have come to depend on manufactured inorganic fertilizers containing key plant nutrients phosphorus, nitrogen and potassium to enhance soil fertility, especially in the otherwise poor soils of most tropical settings. But while all three are relatively abundant in nature, commercially viable sources of phosphorus to make these fertilizers could be exhausted just a few decades from now. That prospect, which remains a source of heated debate, has spurred a drive to recover the significant quantities of this element that disappear in the waste streams of cities and farms.