🚀 go-pugleaf

Sorry I dont have a direct answer to your question, Onno
but for others who might be interested to do some reading
on faith of nitrogen on land, there is a unique book written
in 1979 by Raymond C Loehr et al called "Land Application of
Wastes" Vol. II. which is worth borrowing. Chapters are
written in modules as an instructional unit for self-education.
There is a chapter on "Nitrogen Considerations" as well as one
for "Monitoring at Land Application Sites". The book is one
of Van Nostrand Reinhold Environmental Engineering Series
publications.

From: Eng-leong Foo, Stockholm.