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Phosphate fertilizers are applied to the soil surface, especially in vineyards in production in subtropical regions. Nowadays, phosphorus (P) is not incorporated into the soil to avoid mechanical damage to the root system in orchards. However, over the years, successive surface P applications can increase the P content only in the topsoil, maintaining low P levels in the subsurface, which can reduce its use by grapevines. For this reason, there is a need to propose strategies to increase the P content in the soil profile of established orchards. The study aimed to evaluate the effect of management strategies to (i) increase the P content in the soil profile; (ii) enhance the grape production; and (iii) maintain the grape must composition. An experiment on the 'Pinot Noir' grape in full production was carried out over three crop seasons. The treatments were without P application (C), P on the soil surface without incorporation (SP), P incorporated at 20 cm (IP20), P incorporated at 40 cm (IP40), and twice the P dose incorporated at 40 cm (2IP40). The P concentration in leaves at flowering and veraison, P content in the soil, grape production and its components, and chemical parameters of the grape must (total soluble solids, total polyphenols, total titratable acidity, total anthocyanins, and pH) were evaluated. The P concentration in leaves did not differ among the P application modes. The application of P associated with soil mobilization, especially at 20 cm depth, increased grape production. The P application modes did not affect the values of the chemical parameters of the grape must except for the total anthocyanins, which had the highest values when the vines were subjected to 2IP40. Finally, the P application and incorporation into the soil profile was an efficient strategy for increasing the grape production in full production vineyards. [ABSTRACT FROM AUTHOR]

Fruit crops under soil conservational management might sequester carbon (C) in soils and mitigate greenhouse gases emissions. Using grape pomace residues as soil amendment holds promise for sustainable viticulture. However, its actual capability to increase soil organic carbon (SOC) and nitrogen (N) is unknown, especially in subtropical climates. This research aims to investigate whether grape pomace compost and vermicompost can increase SOC, total N (TN), and C and N stocks in subtropical vineyards. Two vineyards located in Veranópolis, in South Brazil, one cultivated with 'Isabella' and the other with 'Chardonnay' varieties, were annually amended with these residues for three years. We quantified SOC and TN in each condition in different soil layers, as well as C and N content in two different granulometric fractions: mineral-associated organic matter (MAOM) and particulate organic matter (POM). C and N stocks were also calculated. Despite potential benefits, neither treatment enhanced SOC, its fractions, or C stocks. In fact, vermicompost was rapidly mineralized and depleted SOC and its fractions in the 0.0 to 0.05 m layers of the 'Isabella' vineyard. Our findings indicate that the tested grape pomace residues were unable to promote C sequestration in subtropical vineyards after a three-year period. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate Cu, Zn, and Mn fractions in vineyard soils in two important wine-growing regions in Latin America, which have soils with different soil organic matter (SOM) and clay contents. Soils were collected from vineyards aged 35, 37, and 39 years (Serra Gaúcha) and 13, 19, and 36 years (Campanha Gaúcha). In each region, soils were collected from a non-anthropized area, and in the oldest vineyards, the collection was conducted on and between the planting lines. The available and total Cu, Zn, and Mn contents were analyzed in addition to the chemical fractions. The ΔCu, ΔZn, and ΔMn were also calculated by subtracting the contents of each fraction of the vineyards from the reference areas. The use of fungicides promotes increased metal contents in vineyard soils. In soils with high SOM contents, Cu tended to increase in the organic fraction in surface and depth. In contrast, Zn increased in the residual fraction, and Mn increased in most bioavailable fractions. Cu and Zn increased their contents in soils with low SOM and clay contents in the organic and mineral fractions. Mn accumulated in the mineral and residual fractions. [ABSTRACT FROM AUTHOR]

Efficient marketing of winegrapes involves negotiating with potential buyers long before the harvest, when little is known about the expected vintage. Grapevine physiology is affected by weather conditions as well as by soil properties and such information can be applied to build yield prediction models. In this study, Partial Least Squares Regression (PLSR), Cubist (CUB) and Random Forest (RF) algorithms were used to predict yield from imputed weather station data and soil sample analysis reports. Models using only soil variables had the worst general results (R2 = 0.15, RMSE = 4.16 Mg ha−1, MAE = 3.20 Mg ha−1), while the use of only weather variables yielded the best performance (R2 = 0.52, RMSE = 2.99 Mg ha−1, MAE = 2.43 Mg ha−1). Models built with CUB and RF algorithms showed signs of overfitting, yet RF models achieved the best average results (R2 = 0.58, RMSE = 2.85 Mg ha−1, MAE = 2.24 Mg ha−1) using only weather variables as predictors. Weather data imputation affected RF and CUB models more intensely while PLSR remained fairly insensitive. Plant age, yield level group, vineyard plot, May temperatures, soil pH and exchangeable concentrations of Zn, Cu, K and Mn were identified as important predictors. This exploratory work offers insights for future research on grape yield predictive modeling and grouping strategies to obtain more assertive results, thus contributing to a more efficient grapevine production chain in southern Brazil and worldwide. [ABSTRACT FROM AUTHOR]

The Compositional Nutrients Diagnosis (CND) can establish indexes that establish deficiency, normality or excess, and even critical levels (CL) or sufficiency ranges (SR) in grapevine leaves. However, this information is scarce in 'White Moscato' and 'Bordeaux' cultivars cultivated in subtropical regions of the world. The study aimed to propose the CND, CL and SR indexes of nutrients in leaves of 'Bordeaux' and 'White Moscato' grapevine cultivars, cultivated in subtropical conditions. Leaves were collected from 105 'White Moscato' and 'Bordeaux' vineyards. Leaves were prepared, dried, ground and subjected to chemical nutrient analysis. Productivity was evaluated. The nutritional status of the grapevine was calculated using the CND method. The CND-r² indexes were effective in establishing the nutritional status of 'White Moscato' and 'Bordeaux' grapevines, in relation to the concentration of nutrients in leaves of N, P, K, Ca, Mg, B, Cu, Fe, Mn and Zn in deficient, adequate and excessive concentrations. The application of the CND method in the grapevine database showed lower SRs for macronutrients N, K, Ca, Mg and S, and the breadth of the nutritional range for nutrients N, K, Mg, and Fe was smaller than reported in literature. The CND methodology established the critical level and nutrient sufficiency ranges suitable under current grapevine production conditions. Multi-nutrient combinations were more effective than the analysis of a single nutrient in expressing that the limitation of a certain element can reduce the productivity of the grapevines. [ABSTRACT FROM AUTHOR]

Copper (Cu) and zinc (Zn) fraction accumulation and adsorption capacity were evaluated in sandy-soil after 16 pig slurry (PS) and deep-litter (DL) applications under subtropical climate. Sixteen PS and DL applications to a Typic Hapludalf increased soil Cu and Zn soluble, exchangeable, mineral, organic, and total fractions. Cu mostly accumulated in organic and residual fractions (1.03, 4.39, 9.81, and 9.68, 12.9, 13.98 mg Cu kg−1 in the control, PS, and DL, respectively), whereas Zn presented a greater increase in mineral and exchangeable fractions (0.42, 6.39, 15.46 and 1.67, 8.96, 14.83 mg Zn kg−1 in the control, PS, and DL, respectively). Manure applications changed Cu and Zn adsorption behavior, with the greatest (895.8 mg Cu kg−1 and 945.9 mg Zn kg−1) adsorption occurring in DL, which is related to the 1.5- and 1.6-times organic matter increase compared to PS and control. Cu showed a preference for soil exchangeable sites under the competitive adsorption system, reducing Zn absorption about 11 and 6 times in the PS and DL, respectively. Application of pig manure rates based solely on crop N demand is unwise as it potentiates Cu and Zn accumulation, Zn bioavailability, increasing the risk of Zn toxicity and transference to aquatic environments. [ABSTRACT FROM AUTHOR]