In this episode of The Acres U.S.A. Podcast, Taylor sits down with David Knaus, founder and president of Apical Crop Science, to explore the world of leaf sap analysis, plant nutrition, and nutrient density.

David explains how leaf sap testing differs from traditional tissue testing and how analyzing both new and old leaves can reveal nutrient imbalances, antagonisms and excesses that may otherwise go unnoticed. The conversation dives into how targeted nutrition can reduce unnecessary inputs, improve crop resilience, and even help growers transition away from pesticides and conventional fertility programs.

They also explore some of the lesser-understood relationships in plant nutrition, including aluminum, silicon, carbon, calcium and sodium, and how these interactions can influence plant health and susceptibility to insects and disease.

The conversation also looks toward the future of agriculture, including Apical's nutrient density testing, secondary metabolites, biofortification, artificial intelligence and the potential for growers to market crops based on their nutritional characteristics.

David will also be speaking at the 51st Annual Eco-Ag Conference & Trade Show, December 1–4, 2026, in Iowa City, Iowa.

Thank you to our Sponsors of Today’s Episode:

Azure Standard: https://www.azurestandard.com/

American Farmland Trust: https://farmland.org/

Important Links from Today’s Episode:

Members site: https://members.acresusa.com

Acres U.S.A. Memberships: https://eco-farming.com/

Eco-Ag 2026 Tickets: https://www.conference.acresusa.com/

Eco-Ag 2026 Exhibitor Information: https://conference.eco-ag.com/booth-selection-page-page

Apical Crop Science Website: https://apical-ag-home.com/

David’s Webinar with Acres U.S.A.: https://youtu.be/mMHgzYzOAXk?si=1TepwuSDraVSo5dh