Mechanical pruning and soil organic amendments in vineyards of Syrah: effects on wine mineral composition

The interaction of mechanized pruning systems and soil organic amendment can affect vine vegetative and reproductive growth. However, since organic amendments supply several mineral elements, namely heavy metals, this study aimed to understand the effects of the interaction between these two practices on the mineral composition of wine. Two field trials were implemented in ‘Syrah’ vineyards in two Portuguese wine regions (Lisboa and Tejo). Mechanical hedge pruning was compared with hand spur pruning and four different organic amendments were tested: biochar, municipal solid waste compost, cattle manure and sewage sludge. The nitrogen (N), phosphorus (P) and potassium (K) wine contents were significantly reduced by mechanical pruning while calcium (Ca) and magnesium (Mg) contents were tendentially higher in this pruning system. Mechanical pruning also reduced the content of some minor elements, such as arsenic (As), molybdenum (Mo) and nickel (Ni). In 2014, the year with the higher reproductive growth, some other elements also decreased as a consequence of the mechanical pruning (gallium - Ga; lithium – Li; rubidium - Rb, thallium – Tl; yttrium - Y). Concerning the organic amendments, sewage sludge was associated with the wines with the lowest P and iron (Fe) content. Ca content was tendentially higher in municipal solid waste compost and sewage sludge treatments. Mechanical pruning and organic amendments had different effects on the mineral composition of wine, according to each specific element. However, the legal limits, recommended by OIV and established by European Union, as well as the technical limits, adopted by winemakers, were never exceeded and the interaction of both practices does not seem to be a problem in what concerns to the mineral composition of the produced winesA interação entre a poda mecânica e a aplicação de corretivos orgânicos ao solo pode afetar o crescimento vegetativo e reprodutivo da videira. No entanto, uma vez que os corretivos orgânicos fornecem vários elementos minerais, nomeadamente metais pesados, este estudo teve como objetivo compreender os efeitos da interação entre estas duas práticas na composição mineral do vinho. Foram implementados dois ensaios em vinhas de ‘Syrah’, em duas regiões vitivinícolas Portuguesas (Lisboa e Tejo). A poda mecânica em sebe foi comparada com a poda manual e quatro diferentes corretivos orgânicos foram testados: biochar, resíduos sólidos urbanos compostados, estrume de bovino e lamas de uma estação de tratamento de águas residuais. Os teores de azoto (N), fósforo (P) e potássio (K) no vinho foram significativamente reduzidos pela poda mecânica, enquanto os teores de cálcio (Ca) e magnésio (Mg) foram tendencialmente maiores neste sistema de poda. A poda mecânica também reduziu o teor de alguns elementos minoritários, como arsénio (As), molibdénio (Mo) e níquel (Ni). Em 2014, o ano de maior crescimento vegetativo e reprodutivo, alguns outros elementos também foram reduzidos pela poda mecânica (gálio - Ga; lítio – Li; rubídio – Rb; tálio – Tl; ítrio Y). No que diz respeito aos corretivos orgânicos, as lamas de depuração produziram os vinhos com os menores teores de P e ferro (Fe). O teor de Ca foi tendencialmente mais elevado na modalidade com resíduos sólidos urbanos compostados e lamas de estação de tratamento de águas residuais. A poda mecânica e os corretivos orgânicos tiveram efeitos diferentes na composição mineral do vinho, de acordo com cada elemento específico. No entanto, os limites legais, recomendados pela OIV e estabelecidos pela legislação da União Europeia, e os limites técnicos adotados pelos enólogos nunca foram ultrapassados, pelo que a interação de ambas as práticas não parece ser um problema no que diz respeito à composição mineral dos vinhos produzidosinfo:eu-repo/semantics/publishedVersio

Mechanical pruning and soil organic amending in two terroirs. Effects on wine chemical composition and sensory profile

The knowledge about the interaction between mechanical pruning and soil organic amending is still scarce. This study aimed to examine the effects of the interaction between these two practices on wine quality. Syrah grapes from two trial fields in Portugal subjected to two different pruning systems (mechanical pruning; hand spur pruning) and five different organic amendment treatments (control, biochar, municipal solid waste compost, cattle manure, and sewage sludge) were harvested and vinified for four years. Mechanical pruning significantly reduced wine alcoholic strength, pH, and total anthocyanins. Mechanical pruning and organic amendments, tendentially reduced wine total phenols and tannin power, known as an “estimation of the astringency potential of the wines”. Tasters found low but significant differences in global appreciation with the pruning system. Sludge tended to reduce wine global appreciation more than municipal solid waste compost and cattle manure, while biochar had no effect on tasters’ preference when compared to the control. There was strong relation between yield and tasters’ preference only above 6 kg/vine and 8 kg/vine depending on the terroir. Mechanical pruning tendentially has significant effects on wine quality when yield raises above a certain level. Thus, with this pruning system, the choice of the organic amendment and its amount must be done considering the destiny of the produced grapes. To the best of our knowledge, effects of the interaction of mechanical pruning with soil organic amending on wine quality are a noveltyinfo:eu-repo/semantics/publishedVersio

Mechanical pruning and soil organic amendments in vineyards of ‘Syrah’: effects on wine mineral composition

The interaction of mechanized pruning systems and soil organic amendment can affect vine vegetative and reproductive growth. However, since organic amendments supply several mineral elements, namely heavy metals, this study aimed to understand the effects of the interaction between these two practices on the mineral composition of wine. Two field trials were implemented in ‘Syrah’ vineyards in two Portuguese wine regions (Lisboa and Tejo). Mechanical hedge pruning was compared with hand spur pruning and four different organic amendments were tested: biochar, municipal solid waste compost, cattle manure and sewage sludge. The nitrogen (N), phosphorus (P) and potassium (K) wine contents were significantly reduced by mechanical pruning while calcium (Ca) and magnesium (Mg) contents were tendentially higher in this pruning system. Mechanical pruning also reduced the content of some minor elements, such as arsenic (As), molybdenum (Mo) and nickel (Ni). In 2014, the year with the higher reproductive growth, some other elements also decreased as a consequence of the mechanical pruning (gallium - Ga; lithium – Li; rubidium - Rb, thallium – Tl; yttrium - Y). Concerning the organic amendments, sewage sludge was associated with the wines with the lowest P and iron (Fe) content. Ca content was tendentially higher in municipal solid waste compost and sewage sludge treatments. Mechanical pruning and organic amendments had different effects on the mineral composition of wine, according to each specific element. However, the legal limits, recommended by OIV and established by European Union, as well as the technical limits, adopted by winemakers, were never exceeded and the interaction of both practices does not seem to be a problem in what concerns to the mineral composition of the produced wines