Ecco riportata di seguito la relazione “VINE PERFORMANCE AND WINE COMPOSITION OF CHARDONNAY IN RELATION TO ORGANIC SOIL AMENDMENT IN MEDITERRANEAN ENVIRONMENT” a cura di L. Tarricone, D. Di Gennaro, G. Debiase, A.M. Amendolagine, G. Masi.
CREA, Council for Agriculture Research and Economics, Research Unit for Viticulture and Enology in Southern Italy, Turi (BA), Italy.
Preservation and improvement of soil organic matter content on soil assets in vineyard are key goals of agroecosystem resilience against climate change and its negative effects on grapevine water status and vine physiology.
There is still a lack of information on the effects of organic amendments on grapevine functioning and yield performance. The following research was carried out during the 2016 season in a commercial Chardonnay vineyard (silty-clay soil with pH 8 and CaCO3 content around 8%), located in Apulia region (Murgia hills) according to a randomized block design, where one factor of fertilization (composted municipal solid organic wastes) was tested. Treatments compared were: no fertilized control vines (NFC), moderate fertilized vines (D1) at rate of 1 kg vine-1 of organic amendment (4.3 ton/hectare, at the rate of 86 kg N ha-1), high fertilized vines (D2) at rate of 1.5 kg vine-1 (6.6 ton/hectare, 132 kg N ha-1).
Leaf gas exchange during growing season (shoot growth, flowering, pea-size and veraisòn) did not shown significant differences in term of net CO2 assimilation, stomatal conductance, transpiration and water use efficiency. However, lower leaf temperatures on D1 and D2 treatments were observed. Vine fertilized with organic amendment shown a better grapevine water status (midday stem water potentials) during warmest summer days since organic compounds improve the soil water retention capacity.
Monthly field measurements of greenness leaves (SPAD index) revealed highest green color intensity of leaves by D2 treatments (+ 11%) related to highest nitrogen amount.
Compared to unfertilized vines, D2 vines (high amendment dose) determined a significant increase in yield per vine (+21%) as a result of highest shoot fruitfulness.
At harvest, grapes had the same chemical composition with no differences in term of sugar content and pH, while an increment of titratable acidity on D1 and D2 treatments was noted. Wines of different treatments have shown similar chemical parameters (alcohol content, titratable acidity and pH). Our preliminary results indicates that application of an high level of soil organic amendment on Chardonnay vines improve grapevines yield while improving soil properties (soil organic content and water retention), contrasting summer drought effect on vines in Mediterranean environment.