Lecture 27 – Soils: Restricted Access


Addition of nitrate fertilizer to conventional crops has caused a slew of downstream problems, such as groundwater contamination, and dead zones in the ocean due to excess nitrogen runoff. Failure to understand the true mechanisms behind plant-soil nutrient exchange, as well as the persistent desire to mechanize agricultural ecosystems, are the root causes of these ecological disasters. It is the biology in the soil that provides the nutrients, and so it is the biology that we must take care of in order to grow healthy, abundant plants.

So what is the biology of the soil? Larry teaches the class about nutrient migration, decomposition, root growth, rhizosphere interactions, beneficial microbes, the role of micro-organisms, the effects of plowing on the soil microbial community, and ways to build soil. He also discusses plant nutrients, animals, and composting worms.