A growing global population and climate change threaten the availability
of many critical resources, and they are directly impacting the food and
agriculture sector. Therefore, new cultivation technologies must be
rapidly adopted and implemented to secure the world’s food needs.
Closed-loop greenhouse agriculture systems provide an opportunity to
decrease resource reliance and increase crop yield. Greenhouses provide
versatility in what can be grown and the resources required to function.
Greenhouses can become highly efficient and resilient through the
application of a closed-loop systems approach that prioritizes
repurposing, reusing, and recirculating resources. Here, we employ a
text mining approach to research the available research (meta-research)
and publications within the area of closed-loop systems in greenhouses.
This meta-research provides a clearer definition of the term closed-loop
system within the context of greenhouses, as the term was previously
vaguely defined. Using the meta-research approach, we identify six major
existing research topic areas in closed-loop agriculture systems, which
include models and controls, food waste, nutrient systems, growing
media, heating and energy. Furthermore, we identify four areas that
require further urgent work, which include the establishment of better
connection between academic research to industry applications, clearer
criteria surrounding growing media selection, critical operational
requirements of a closed-loop system, and the functionality and synergy
between the many modules that comprise a closed-loop greenhouse system.