Experimental addition of olive mill waste compost in an old agroecosystem: identifying main short-term vegetation responses Claudia Angiolini . Jose ´ Vesprini . Paolo Castagnini . Patricia Torres . Alessia Nucci . Claudia Perini Received: 27 October 2016 / Accepted: 7 January 2018 Ó Springer Science+Business Media B.V., part of Springer Nature 2018 Abstract Olive mill wastewater (OMW) is the main residual product of olive processing and its disposal can represent a relevant environmental issue in Mediterranean countries. OMW is characterised by high pollutant load, salinity and phytotoxic levels of polyphenols, but also by a high amount of organic compounds and plant mineral nutrients. In this perspective, a technology named MATReFO was developed, with a final dry product easy to transport for commercial use. Here, we assessed the short-term effects of OMW and MATReFO applications on spontaneous vegetation in an old agroecosystem. Following a randomized block design soil was amended with different quantities of OMW or MATReFO and vegetation was sampled for 4 years after the treatments. Multivariate and univariate analyses of plant data showed that: (1) only high volume of MATReFO affected spontaneous vegeta- tion, whereas OMW and low volume mixture addition did not determine significant effects; (2) plant species composition and abundance varied significantly among years and exhibited considerable variation over the study period, particularly with high volume of MATReFO; (3) vegetation dynamic had already undergone first steps of natural succession in control and almost all treatments. Our results revealed no negative effects of olive mill waste compost addition in plant community assemblage, since vegetation changes can be mainly related to the abandonment of soil tillage. Therefore, we can assert that OMW and MATReFO can be discharged in abandoned agroe- cosystems without short-term effects on natural vegetation. Keywords Uncultivated fields Á Olive mill wastewater (OMW) Á Plant community Á Soil amendments Á Vegetation succession Á PERMANOVA Introduction Olive oil production is a very important economic activity, particularly for Spain, Italy and Greece. Moreover, olive oil production is no longer restricted to the Mediterranean basin, and new producers such as Australia, USA, South America and North Africa will also have to face the environmental problems posed by olive-mill wastes. C. Angiolini (&) Á P. Castagnini Á A. Nucci Á C. Perini Dipartimento di Scienze della Vita, Universita ` degli Studi di Siena, via P.A. Mattioli 4, I-53100 Siena, Italy e-mail: claudia.angiolini@unisi.it J. Vesprini Facultad de Ciencias Agrarias, UNR, IICAR CONICET, cc14 S2125, ZAA, Zavalla, Argentina P. Torres Facultad de Ciencias Agrarias, UNR, CIUNR, cc14 S2125, ZAA, Zavalla, Argentina 123 Agroforest Syst https://doi.org/10.1007/s10457-018-0189-7