Effect of Grape Pomace Varieties and Soil Characteristics on the Leaching Potential of Total Carbon, Nitrogen and Polyphenols

Grape pomace (GP) has an added value because of its contribution to carbon (C) and nitrogen (N) in soils when applied as organic fertilizer. Macronutrients from GP are translocated into the soil after amendment, but little is known about factors that may influence mobility C, N bioactive molecules, i.e., polyphenols, column. We investigated macronutrient content GP, derived two red (Dornfelder Pinot noir) white grape varieties (Riesling blanc). For that, three different (loamy sand RefeSol01A, silt loam RefeSol02A a vineyard soil) were evaluated column model using application rate 30 t ha−1. The three-step lab-scale approach included analysis total polyphenols expressed polyphenolic (TPC) in: (a) fresh representing amount TPC; (b) with rainwater, aqueous extractable fraction (c) leaching potential. Our results showed C/N ratios wider compared ones. Higher TPC values measured Dornfelder noir varieties. Analysis water-extractable C recovery reach up 48% blanc, which also corresponds highest contribution. Extractable higher by factor 2.4. mobilized rainwater through However, used experiment was not indicative accumulation soil. Compared control (no application), significantly leachates GP-treated soils, contrast values. Up 10% leached strongly depended on combination type variety. Generally, sandy more acidic even distribution phenolics high (up 92%) neutral silty Most polyphenol could accumulate upper layer (0–10 cm). These provide first insights macronutrients point out need relate those experiments properties order avoid nutrients or adjacent ecosystems.