A Note from Christophe, our staff microbioigist
Dear CSA Members,
At the present time two types of composting are done at FHF: thermophilic and worm composting (vermicomposting). Thermophilic composting takes advantage of the heat produced by the microbial organisms present and requires that the compost is monitored for temperature, aeration, and moisture. This process requires mechanical turning and watering. Vermicomposting or composting with the worm Eisenia fetida is done at ambient temperature (between 60-90 F) and requires less frequent monitoring of moisture and aeration. In thermophilic composting, very large amounts of undecomposed material (fruit, leaves, branches, coffee, kitchen residue, horse manure) can be processed (FHF produces about 4000 tons of compost per year). FHF produces about 25-250 tons of vermicompost a year. In vermicomposting, the worms process material that is pre-decomposed by similar organisms that are present in thermophilic compost. The use of both types of compost keep the soil healthy and help in suppressing various plant diseases. However, thermophilic compost has poorer structure and limited amount of plant available nutrients as compared to vermicompost. Also, it is easier to custom tailor vermicompost to suppress certain plant diseases than thermophilic compost.
We plan to ramp up production of vermicompost with a process that is more efficient and easier to manage. Also, this new approach will make it easier to increase the numbers of certain beneficial and disease suppressive microorganisms. Typically, the soil and the thermophilic compost at FHF is not as rich in beneficial nematodes as it should and could be. The vermicompost has higher numbers of beneficial nematodes. Also, we plan to deal with the codling moth problem (that affects pears and apples) by inoculating the vermicompost with entomopathogenic nematodes.
The new change is the use of ventilated macrobins (with a capacity of 1200-2000 lbs) to grow the E. fetida worms. These bins are well aerated slits for air and are normally used (only in August and early fall) to store pears and apples. These bins are easily moved around with a tractor and thus vermicompost can easily be mixed with thermophilic compost. These bins hold water well because of their structure and can easily be protected from the elements. The macrobins are ideally suited to grow beneficial nematodes (nematodes that are predators of root-feeding nematodes) and entomopathogenic nematodes (EPNs), which appear to be effective biological control agents of cocooned codling moth larvae. The macrobins will also be very suitable to conduct experiments which might help us to tailor the compost to different crops. Finally, the macrobins should dramatically increase the tonnage of vermicompost produced at FHF!