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.
The water that made the San Joaquin Valley an agricultural powerhouse also spelled its doom. Because most water contains salt, irrigating adds salt to soil over time.
Agronomist Andrew McGuire looks at too opposite problems in managing soil and then lays out a few principles for staying away from two extremes.
While crop probiotics offer an ecologically friendly option for farmers looking to improve and protect their harvests, the Australian market is far from reliable.
Our research group was asked to evaluate commercial crop probiotics. Over a year of experimentation on a sugarcane farm, we tracked the supposedly beneficial bacteria and fungi of two Australian probiotics products from soil to crop.
DNA analysis didn’t detect changes in root-associated bacteria, but the composition of root-associated fungi changed.
There are certain requirements that agriculture must meet to produce food and to keep producing food. We should view them as a hierarchy, such that if the top requirement is not attained, the lower requirements do not mean much, but once the top requirement has been met, we can move to the next one, provided that how we do it does not threaten any of the requirements above it. Each component is required, but not sufficient; all of them are needed.
Microbes can unlock phosphorus and other micronutrients so that plants can use them. We developed a combination of four bacteria that are exceptionally good at making phosphorus available to plants, leading to bigger, healthier plants. They do this by releasing specialized molecules that break the bonds between phosphorus and soil particles. To get this technology into the hands of farmers who can use it, we launched a startup company called Growcentia and started selling our first product, which is called Mammoth P.