Edafología. Volumen 7-2. Mayo 2000. pag 125-134.
Abstract
Dry olive cake, alone or mixed with biosolids, was stabilised in a vermicomposting process. Unprocessed and vermicomposted by-products were then used as organic mulches in a greenhouse experiment. The control contained only degraded soil. Soil biochemical activities (dehydrogenase, urease and phosphatase) were studied in the rhizosphere of pepper (Capsicum annuum, L.). Changes in plant growth and nutrient content of C. annuum following addition of mulches were also measured. The addition of dry olive cakes as organic mulches increased P and K concentration in pepper leaves. In contrast, N concentrations were unaffected. Rhizosphere dehydrogenase and phosphatase activity were increased by incorporation of mulches, the last especially if they were previously vermicomposted. Urease activity in the rhizosphere was inhibited under unprocessed mulches, but this inhibitory effect disappeared when dry olive cakes were previously vermicomposted. Dry olive cake should be vermicomposted prior to use as mulching media in horticultural crops.
Keywords: Olive cake; Mulches; Pepper (Capsicum annuun, L.); Rhizosphere; Enzyme activities; Plant nutrition