CU IMMOBILIZATION AND LOLIUM PERENNE DEVELOPMENT IN AN ACID VINEYARD SOIL AMENDED WITH CRUSHED MUSSEL SHELL

Cu pollution and erosion pose an important risk of degradation in vineyard devoted soils. Therefore, minimizing harmful effects of Cu in the soil and avoiding erosion are important challenges in vineyard soil management. The addition of low cost bio-adsorbents to the soil which decreased Cu bioavailability in soil and/or increased cover crops development may be an important management practice for soil stabilization in vineyards. This study investigated the effect on Lolium perenne performance because of crushed mussel shell (CMS) amendment in an acid Cu-polluted vineyard soil. Quadruplicate samples of a Cu polluted soil were amended with 4 doses (0, 6, 24 and 48gkg(-1)) of CMS by in lab pots, where L. perenne was sowed and incubated for 51days. The soil pH, as well as Cu bioavailability and exchangeable Cu, was analysed. The effect of CMS on L. perenne response was measured using plant germination, plant growth and Cu uptake. The plant growth was assessed in both roots and shoots by measuring length and biomass. Cu uptake by roots and shoots was also determined. The CMS amendment on the acid vineyard soil increased the pH and reduced the bioavailable Cu concentration. Moreover, shoot and root growth increased for low and intermediate CMS doses, and decreased for higher doses. The increase in plant growth corresponded with increases in soil pH up to 70, whereas the highest mussel shell dose caused a pH increase over the neutrality (78). The CMS amendment decreased Cu uptake by both, roots and shoots, and it was highly correlated with changes in Cu bioavailability in the soil. The CMS amendment on a Cu-polluted acid soil presented positive effects on Cu immobilization and L. perenne growth. However, mussel shell application must be performed carefully, taking into account that high doses can lead to decreases on plant growth. Copyright (C) 2016 John Wiley & Sons, Ltd.