
In 1904, Professor Lorenz Hiltner, Director of the Royal Bavarian Agriculture-Botanical Institute in Munich, coined the word ‘rhizosphere‘ in his seminal publication “Uber neuere Erfahrungen und Probleme auf dem Gebiete der Bodenbakteriologie unter besonderden berucksichtigung und Brache.” His concept was that a defined zone of soil around the roots of a plant would be an area where ample micro-organisms and biochemical processes important for the development of the plant would be located.

In the 100 years following this definition, the concept of the rhizosphere has grown in importance for research in plant sciences, agriculture, microbiology and beyond. in 2004, on the centenary of Hiltner’s publication, the first Rhizosphere conference was held in Munich, as a tribute to his life and work. It has since become a regular and successful event for researchers in many disciplines, and the Rhizosphere 4 conference took place in June last year in Maastricht, the Netherlands.
To celebrate the topics presented at this conference, the SpringerOpen journal Chemical and Biological Technologies in Agriculture is publishing the article collection “Bioeffectors for a sustainable intensification of Agriculture,” Guest Edited by Editorial Board Member Professor Günter Neumann.

The first two articles in this series published in April. The first looks at bio-refining grasses to yield an aqueous extract (“grass juice”), and assessing its use as a plant biostimulant: a substance that can be applied to plants or their rhizosphere to aid growth and development. The second paper investigates the physicochemical characteristics of such biostimulants, and the analytical tools that can be used to characterize them.
As with all papers published in Chemical and Biological Technologies in Agriculture, the papers are free to read, and more articles will be added to the collection “Bioeffectors for a sustainable intensification of Agriculture” as they are published, so watch this space!