[compost_tea] Re: worm castings vs vermicompost

[z_willus_d]

All stolen from a post to the compost_tea group at yahoo. I thought there was enough great information listed in allison hornor's post to repeat it here. For those interested in vermi-composting as I am, as least.
-naysen

Jack, ALH, A Rangarajan, SW Culman, T Sooksa-Nguan and JE Thies (2011) Choice of organic amendments in tomato transplants has lasting effects on bacterial rhizosphere communities and crop performance in the field. Applied Soil Ecology 48(1): 94-101.
http://dx.doi.org/10.1016/j.apsoil.2011.01.003

If you check out some of the work I did from my MS, we compared thermophilic compost and vermicomposts made at the same facility (Pacific Garden Company in 2004 and Worm Power in 2005) made from the same feedstocks and we found striking differences. Total nutrients were not different, but both vermicomposts had up to 7 times higher nitrate (a plant available form of N) compared to thermophilic composts. We assume this is due to the denitrifying bacteria in the earthworm gut, but did not test this directly. We also found measurable differences in root associated bacterial communities in the greenhouse and all the way out to August in the growing season after seedlings had been transplanted to field soil.

Total yields were not different, but vermicomposted dairy manure used only in the transplant medium gave significantly higher early yield of organic tomatoes than thermophilically composted dairy manure. And that is with no other nutrients added during the growing season since it was certified organic production. Bottom line, more research is always needed, but I'm happy to have contributed some information to this topic. The take home message from our study is that the organic amendment you choose to add to your transplant medium can impact the rhizosphere bacterial community for the life of the crop plant.That is a powerful tool once we start to develop predictive models for how different rhizosphere communities impact plant health and crop yield.

You can find all of our extension reports here:
http://cwmi.css.cornell.edu/vermicompost.htm

These are most related to the topics above:
http://cwmi.css.cornell.edu/organictransplant.pdf
http://cwmi.css.cornell.edu/temperaturetrials.pdf

Worm Power is continuing to collaborate with Neil Mattson at Cornell on greenhouse nutrient management with vermicompost and non-aerated liquid vermicompost extract. Can't wait to see those papers when they come out.

And some of my grower talks on my disease suppression research here:
http://www.youtube.com/playlist?list=PLEDAF2959AE416A56

[Redbaron]

Thanks for the links...and go worm power! hehehehe