Can soil nitrate explain polyphenol and anthocyanin content in vineyard with similar available soil water regime?
Nitrogen (N) is quite important nutrient in grapevine development and must quality, but under Mediterranean climatic conditions, available soil water (ASW) during grapevine development can also influence vigour and must quality. The aim was to determine the influence of soil nitrate (NO3–) availability on N foliar, yield, and must quality in vineyards with similar available water holding capacity (AWC). For this purpose, four cv. Tempranillo (Vitis vinifera L.) vineyards were selected. All of them are placed in Uruñuela municipality (La Rioja, Spain), separated less than 2.5 km and in a slope <1 %, in soils with similar soil chemistry properties and with similar rooting depth (ranging between 105 cm and 110 cm). Soil profile was described and analyzed in each vineyard. AWC was determined according to Saxton equations and the evolution of ASW was simulated for each plot and for the period 2010-2014 using the Vineyard-Soil-Irrigation Model (VSIM), considering soil properties and the weather conditions recorded in the study area. The results were calibrated and validated with field soil water measurements carried out in the same period. In addition, soil NO3– content (0-15 cm depth) was determined at bloom, N content in blade was determined at veraison, and yield, concentration of polyphenols and anthocyanins in must were determined at harvests from 2010 to 2014 vintages.
AWC ranged between 128.6 and 146.6 mm. In all vineyards, ASW was higher than 20 % of AWC (which denoted hydric stress absence). Considering the four vintages (n=16), soil nitrate was correlated with N content in Blade (r=0.762, p<0.01), berry weight (r=0.525, p<0.05), and yield (r=0.695, p<0.01), and negatively correlated with polyphenol (r=-0.767, p<0.01), anthocyanins (r=-0.799, p<0.01), and colour index (r=-0.674, p<0.01) in must. In conclusion, soil NO3– could be a suitable indicator to compare the potential quality of musts among vineyards with similar ACW.
Issue: ICGWS 2023
1Departament Agricultural Production ETSIIAB, University Polytechnic of Madrid, Madrid, Spain
2Institute of Grapevine and Wine Sciences (CSIC-University of La Rioja-Government of La Rioja), Logroño, Spain
3Department of Environment and Soil Sciences, University of Lleida-Agrotecnio CERCA Center, Lleida, Spain
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soil nitrogen availability, available water holding capacity, grape quality, Tempranillo