Winemaking is one of the most relevant socio-economic activities in the world, particularly in countries such as Portugal, generating substantial amounts of by-products across its various phases. Managing these by-products presents significant environmental, ecological, and economic challenges. Vermicomposting, the use of earthworms to process and transform organic wastes into nutrient-rich end-products, provides a viable alternative for waste management within the wine sector. This bioprocess also produces vermicompost that enhances soil health and fosters optimal conditions for plant growth, thereby promoting resilient and sustainable viticulture practices. This review explores the various by-products produced by the vine and wine industry, highlighting the potential of vermicomposting. Remarkably, grape marc, the primary solid waste of the winemaking process, has been the most commonly vermicomposted material. In contrast, other vineyard and wine cellar by-products have been comparatively underutilized and understudied in this context. However, we hypothesize that all vine and wine industry by-products have vermicomposting potential, allowing for the production of fertilizers and soil amendments. This approach aligns with the principles of the circular economy, ensuring that all materials stemming from viticulture and wine production are valued and reused, thereby contributing to enhanced sustainability and the preservation of resources like soil.

The soil phosphorus (P) test in Portugal is based on extraction with ammonium lactate (AL) at acidic pH. Because this test is rarely used in other countries, it is desirable to see whether the AL-P values correlate with the more commonly used P tests. In this work, we compared AL-P with bicarbonate-extractable P (Olsen's method) for a group of 48 samples from Portuguese acidic soils differing widely in P status. Despite their contrasting composition, both reagents extracted phosphate from the same sources, albeit in different proportions. Both Olsen P and AL-P were strongly correlated with resin-extractable and dilute electrolyte-desorbable P, which are respectively related to the soil contents in phytoavailable P and P that can be released to runoff or drainage water. Olsen P and AL-P were strongly correlated (R² = 0.870), the correlation became stronger when three overfertilized soils were excluded (Olsen P = 2.35 + 0.45 AL-P; R² = 0.908; P ≤ 0.001, n = 45). No correlation was observed for a group of soils recently fertilized with Gafsa phosphate probably because the acidic AL reagent dissolved residual calcium phosphate, thus overestimating the soil content in desorbable P. On the basis of the present results and the AL-P-based fertility classes used for fertilizer recommendation purposes, Olsen P–based fertility classes were tentatively proposed for Portuguese acidic soils.

In order to diagnose the symptoms of conspicuous magnesium (Mg) deficiency in sweet chestnuts (Castanea sativa Mill.) and to determine its effect on yield, two types of studies were carried out. In study 1, twenty six chestnut groves were selected to assess both foliar and soil nutrient status. In study 2, a twenty year‐old chestnut grove with a conspicuous Mg deficiency was selected and trees were classified according to foliar chlorosis, into three categories, in order to determine the effect of Mg deficiency on several tree growth parameters and yield. Study 1, showed an average foliar Mg concentration of 0.5 g kg−1 in trees with evident leaf chlorosis. When Mg concentration was 0.3 g kg−1 or less premature leaf fall was observed. The symptom free trees had an average Mg concentration of 1.6 g kg−1 or higher. The foliar K/Mg ≥ 9 ratio seemed to be the threshold value above which leaf chlorosis was observed. The ratio N/Mg ≥ 23 also indicated the boundary above which visible Mg deficiencies mig...

The chemical characterization of soil phosphorus (P) desorbed by anion and cation exchange membranes is of major importance to better understand which P forms are available to plants in short‐ and long‐term time periods. Two distinct soils, one acidic and one calcareous, were analyzed for P using two extraction procedures with mixed anion and cation exchange membranes. The short‐term (ST) experiment evaluated the effect of increasing the extraction periods up to 24 h, whereas the long‐term (LT) experiment consisted of a sequential extraction procedure using up to seven successive 24‐h extractions. In both experiments, the Chang and Jackson inorganic P fractionation methodology was carried out after each extraction treatment, and each treatment consisted of three replicates. Data were statistically analyzed by ANOVA and nonlinear regressions. In the ST experiment, increasing the extraction time increased the extracted P according to an asymptotic relationship (y=c−ab ^x ). Extracted P proceeded from the most labile fractions in the acidic soil. In calcareous soils, calcium phosphates may also contribute for extractable P. The LT experiment revealed that a single extraction, regardless of that extraction method, cannot predict the long‐term capacity of soils to supply P to the plants. An exponential relationship (P=a×n ^b ) was found between extracted P and the extraction number. Desorbed P proceeded from the most labile fractions in the acidic soil. However, in calcareous soils, some precaution is needed when considering the biological meaning of the results, because the occluded Fe phosphates also revealed significant decreases, probably due to the redox conditions in which these long extractions are performed.