Soil health and nutrient management: What it can and cannot do

Improved soil health provides several benefits to crops and water quality. However, there are limitations and as a result, some misconceptions exist. This Digital Cafe featured Chad Penn, Research Soil Scientist at USDA-ARS and Adjunct Professor of Agronomy at Purdue University, who addressed how improved soil health impacts soil fertility and nutrient transport, as well as dispelling common myths.

[@marynunn1708]

Respectfully disagree that plants cannot take up organic forms of nutrients. ~14:00. Refer to Dr James White’s research on risophagy cycle where growing root tips absorb whole microbes. Much more efficient than chemical mechanism.

[@chadpenn8303]

Yes, I was making more of a general statement that for macronutrients, inorganic forms of uptake is necessary for sustaining plant growth. Except for chelated micronutrients where the chelate itself is occasionally taken up, organic compounds of macronutrients are unable to be taken up to sustain a plant. e.g. phytic acid or amino acids. Much of this work was conducted in the 1920's where controlled hydroponic studies were used to supply nutrients in a precise form and amount. For example, work by Parker and Pierre. So yes, while a root can uptake an entire microbe, it does not mean that dissolved organic nutrients in a solution, or a microbe for that matter, can sustain growth. Those experiments were very direct and straight-forward: organic uptake rate is not sufficient; they must first be mineralized by microbes. Hoagland and others followed up in the 1950's.