ISHS Acta Horticulturae 172: Composts as Horticultural Substrates
THE USE OF COMPOSTED SLURRY PRODUCED BY METHANOGENIC FERMENTATION OF COW MANURE AS A GROWTH MEDIA |
| Authors: | Y. Inbar, Y. Chen, Y. Hadar |
| Abstract:
The anaerobic digestion of organic matter is a well known technology which is used to produce biogas from wastes, especially manures. The digested slurry is usually used for direct application in the field. We found that by sieving and leaching the digested slurry on a vibrating screen, two major products are obtained: (i) a fibrous material which resembles peat in its physical structure. This fraction is commercially named "cabutz", and may serve as a growth substrate. (ii) an effluent which is similar in its composition to liquid fertilizers. Cabutz was composted in windrows for 100 days. Temperature rose to 55 °C within a week. Chemical analysis of samples taken during compostation revealed that total contents of macroelements (N,P,K), minor elements (Fe, Mn, Cu, Zn) and ash were doubled, and the C/N ratio was reduced from 40 to 15. The pH dropped from 7.5 to 6.6, and the amount of soluble salts rose from 15 to 37 meq/100 g. Growth experiments were conducted under greenhouse conditions. Germination and seedling development of peppers, cucumbers and tomatoes were compared in growth media consisting of raw cabutz, composted cabutz and peat. The raw cabutz had a strong inhibitory effect on tomatoes. This inhibition was not removed by fertilization. For all plants, the composted cabutz appeared to be as good or superior as compared to peat. Fertilization with inorganic fertilizers or slurry effluent increased both plant dry weight and height. | |
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