Amazing that no one has answered this one yet. Perhaps it would be useful to include terms like 'diaries', 'qualitative methods', and 'management reporting' or similar, to see if these help the right people see it. Another important question, of course, is whether farmers need to be paid to do this kind of work, or whether their internal reporting (if any) means it is not extra work.

Hello Simon,

I am not quite sure if I get the right meaning of the term "log" in your question. And I can only answer from the German/ European context.

I have analysed farmers' records of pesticide use for my research. In Germany, farmers are obliged within pesticide use regulation to keep some kind of record of their pesticide applications. In the least this is some kind of little book with hand-written notes, but by now, many farms (in our region many farms are >200 ha, even up to 3000 ha)  have electronic records, huge data bases. They have all sorts of practices in there, tillage, cultivars, yields, etc, mostly for >10years backwards. And they are very detailed for the pesticides, different for the other things depending on the farmer. Large farms tend to monitor their work loads etc. using the record of tillage and sowing operations etc. in this case all these are very detailed too.

Pesticide us is kind of sensitive data, but somehow it's also different in different regions whether farmers are willing to share their data for our research. It seems to be somehow connected to the attitude of the public extension service/ authorities. We have not payed any farmer for the data, but it takes a long talk over a cup of coffee before getting the data.

In Germany there are also 2 networks of farms that provide data to state research institutions and get payed a little fee for the extra work to provide the data in the right format and in full extent. https://www.nap-pflanzenschutz.de/praxis/erfassung-der-realen-pflanzenschutzmittelanwendungen/netz-vergleichsbetriebe-pflanzenschutz/

You also ask about reliability. We have the experience, that it takes a lot of data cleaning. There are typos, wrong names, changing units... About 10% of records have some sort of error that is not easily cleaned, but we do not know whether it's an error from entering the data or whether it was an error in actual use. (e.g. application of a product that is not approved in the given crop).

The only analyses of pesticide data from farms in the US that I am aware of are the analyses of California's pesticide reporting system. Epstein, L., Bassein, S.

Patterns of Pesticide Use in California and the Implications for Strategies for Reduction of Pesticides

(2003) Annual Review of Phytopathology, 41, pp. 351-375.

Hope this helps!

Thank-you so much Jana. This is valuable information. It does indeed sometimes take a cup of coffee or to to get information sometimes, haha. 

You response is much appreciated, thanks for taking the time.