SOIL ENZYME ACTIVITIES RECOVERY AFTER ORGANIC TREATMENTS OF DEGRADED AREAS WITHIN VINEYARDS

Soil enzymes were used to assess the impact of different treatments applied in four farms, each one with three vineyards as replicates, on soil functionality. 8 enzymes related to C, N, S and P cycling were measured and functional diversity indexes were estimated. Three treatments were compared: compost, green manure and dry mulching with respect to degraded and non-degraded soil. The four vineyards showed different enzymatic patterns and response to treatments. Vineyards with the largest difference between degraded and non-degraded soil have benefited more largely from the treatments. In particular, dry mulching seemed to be more effective than green manure or compost, with the exception of San Disdagio. However, the effect the short term

Effect of organic treatments on soil carbon and nitrogen dynamics in vineyard

The work aims to investigate the effects of different soil management strategies on carbon sequestration and total nitrogen in areas of vineyards suffering from loss of soil functionality. Treatments, selected for inter-row management, to re-install soil functionality were based on compost or other organic amendments (COMP), green manure (GM), and dry mulching (DM) strategies using winter legumes and cereals. Cover crops were seeded in fall and mown in late spring, leaved in the ground for mulching in DM or incorporated into the uppermost soil layers in GM. Such approaches were investigated in six vineyards in Italy, six in France, and two vineyards in Slovenia and Turkey. The results showed that COMP significantly increased total organic carbon (TOC) and total nitrogen (Ntot) in the topsoil after one year of application. Also DM tends to increase significantly TOC in the topsoil, but only after two years. Modelling 20-year carbon stock dynamics in Italy vineyards, the average increase resulted 0.49, 0.34, 0.21 and 0.03 Mg C ha-1 yr-1 for COMP, DM, GM and control, respectively

Soil functionality assessment in degraded plots of vineyards

Land transformation to adapt fields to mechanization in perennial crop farming is a common practice which includes land levelling, deep ploughing, stone-breakage and clearing, application of fertilizers and amendments. Manipulation of the natural soil profile along its entire depth can severely disturb the naturally existing chemical physical,biological and hydrological equilibrium (Costantini and Barbetti, 2008; Costantini et al., 2013). The most common effects of the land transformation are mixing of soil horizons and soil truncation, which result in reduction of soil depth and available water, organic matter depletion, enrichment of calcium carbonate content in the topsoil,imbalance of some element ratio, and decline in the activity and diversity of soil biological communities involved in nutrient cycles. A decline in the capacity of soil to accommodate the soil-dwelling organisms causes a strong impact on several ecosystem services, in particular, the growth of the vine, the quality and quantity of the grapes,the production costs and the risk of erosion. These negative effects of a pre-planting mismanagement can occur simultaneously and interact to decrease soil fertility and grapevine performance (Lanyon et al., 2004; Tagliavini and Rombolà, 2001; Martínez-Casasnovas and Ramos, 2009).Since soil spatial variability is usually high, soil manipulations frequently result into reduced soil functionality and decline of soil ecosystem services in defined plots of the vineyards. Sometimes soil degradation in these areas is very high and compromises not only vine performance and crop yield, but also disease resistance of plants to diseases and their survival. The impact of improper soil manipulations in vineyards may be of particular concern, because vineyards are frequently located on marginal hillsides, which are sensitive to soil erosion and characterized by shallow soil depth (Ramos, 2006). This paper wants to show the assessment of soil functionality in degraded areas within two farms in Tuscany. This work reports the results of the first activities in Italian sites of the ReSolVe Core-organic+ project, aimed at restoring optimal Soil functionality in degraded areas within organic European vineyards

Assessment of soil ecosystem in degraded areas of vineyards after organic treatments

In Italian vineyards, it is quite common to have areas characterized by problems in vine health, grape production and quality, often caused by improper land preparation before vine plantation and/or management. Causes for soil malfunctioning can include reduced contribution of the soil fauna to the ecosystem services such as nutrient cycles and organic matter turnover. ReSolVe is a transnational and interdisciplinary project, supported by Core-Organic+ program, aimed at testing the effects of selective agronomic strategies for restoring optimal soil functionality in degraded areas within organic vineyard. For this purpose, the evaluation and biomonitoring of the abundance of soil mesofauna, nematodes and microarthropods, represents an efficient tool to characterize the effects of crop management on soil quality. Assessing enzyme activities involved in the main biogeochemical cycling of C, N, P and S can also provide indication of soil functions and health status. Italian experimental plots are situated in two commercial farms in Tuscany: i) Fontodi, Panzano in Chianti (FI), which has been managed organically for more than 20 years and ii) San Disdagio, Roccastrada (GR), under organic farming since 2014. In each farm, three plots (250 m2 each) in the degraded areas and three relative control plots in the non-degraded areas were selected. The different restoring strategies implemented in each area were: i) compost, produced on farm by manure + pruning residue + grass, ii) faba bean and winter barley green manure, iii) dry mulching after sowing with Trifolium squarrosum L. Each treated and control plot has been studied for soil nematodes, microarthropods, enzymatic activity, and organic matter turnover using tea-bag index, as well as total organic carbon (TOC) and total nitrogen (TN). Soil sampling was carried out to 0-30 cm depth for TOC, TN, enzymes and nematodes and to 10 cm for microarthropods. Tea-bag index was determined following the Keuskamp et al. method (2013), in order to gather data on decomposition rate and litter stabilisation by using commercially available tea bags as standardised test kits. The extraction of nematodes and microarthropods were performed by the Bermann method and the Berlese- Tullgren selector, respectively. The biological soil quality was evaluated by the Maturity Index of nematodes (MI) and Biological Soil Quality index of microarthropods (QBSar). The results from soil sampling before restoring showed significantly lower values of SOC and TN in degraded areas, but no significant differences between degraded and non-degraded areas for enzymes, QBSar, nematode abundance and MI. Fontodi farm, under organic management since many years, showed significantly higher abundance of microarthropods, nematodes and enzymes than San Disdagio farm. The application of restoration techniques in 2016 showed a significant increase of TOC and TN only under compost addition treatment. As regards microarthropod communities, all the treatments showed a sensible increase in abundance and the conservation of high QBSar values. All the treatments increased the fungal feeder activity of nematodes and decreased the number of plant parasitic nematodes taxa. The major pest of grapes, the virus-vector Xiphinema index (Longidoridae), disappeared in the treated plots, whereas it remained in the control plots

Assessment and restoring soil functionality in degraded areas of organic vineyards. The preliminary results of the ReSolVe project in Italy

In both conventional and organic Italian vineyards, it is quite common to have areas characterized by problems in vine health, grape production and quality, often caused by improper land preparation before vine plantation and/or management. Causes for soil malfunctioning can include: reduced contribution of the soil fauna to the ecosystem services (i.e. nutrient cycles), poor organic matter content, imbalance of some element ratio, altered pH, water deficiency, soil compaction and/or scarce oxygenation. ReSolVe is a transnational and interdisciplinary 3-years research project aimed at testing the effects of selected organic strategies for restoring optimal soil functionality in degraded areas within vineyard. The different restoring strategies implemented in each plot will be: i) compost produced on farm by manure + pruning residue + grass, ii) faba bean and barley green manure, iii) sowing and dry mulching with Trifolium squarrosum L. During two years of such treatments, the trend of the soil features and the grapevine status will be monitored in detail, to reveal the positive and negative effects of such treatments. The project involves 8 research groups in 6 different EU countries (Italy, France, Spain, Sweden, Slovenia, and Turkey), with experts from several disciplines, including soil science, ecology, microbiology, grapevine physiology, viticulture, and biometry. The experimental vineyards are situated in Italy (Chianti hills and Maremma plain, Tuscany), France (Bordeaux and Languedoc), Spain (La Rioja) and Slovenia (Primorska) for winegrape, and in Turkey (Adana and Mersin) for table grape. Soil features before implementing restoring strategies showed lower content of soil organic matter and enzyme activities, and higher carbonates in degraded areas than in the non-degraded areas. The Biological Soil Quality values of microarthropods were always high, in comparison with data registered in similarly managed vineyards or stable ecosystems, and the data showed homogeneous patterns within the experimental plots. Nematode abundance, taxa richness and maturity (MI) and plant parasitic (PPI) indices were higher in nondegraded than degraded areas, but differences were not significant. Grapevines in degraded areas of both farms showed less vegetative vigour and significantly lower values in the SPAD colour index. The yield and the weight of the grape bunches and berries were greater in the not degraded. The grapes of degraded areas at harvest had instead a sugar content significantly higher (on average +2.5�Brix). The restoration techniques and the monitoring methodologies developed and tested during the ReSolVe project will be described in specific final guidelines. The restoration techniques will be accessible for all the European farmers and will be low cost and environmental-friendly. A protocol of analyses and measurements between the all partners will allow an effective and comparable monitoring of vineyard ecosystemic functioning in European countries

Ripristino della funzionalità ottimale del suolo in aree degradate di vigneti biologici

Il progetto ReSolve ha voluto testare tre diverse pratiche agronomiche biologiche per il recupero di aree di vigneto con suoli degradati, per cause legate allo scasso, ai livellamenti e all’erosione. L’obiettivo primario per il recupero di queste aree è quello di aumentare la dotazione di sostanza organica nel suolo, così da migliorarne la struttura, l’areazione, la fertilità chimica e l’attività biologica. Le pratiche testate sono state: la forte aggiunta di compost, in quantità di circa 40 tonnellate ad ettaro; un sovescio con leguminose e graminacee (in Italia orzo e favino); una copertura con leguminose riseminanti per il taglio pre-estivo e la pacciamatura secca dell’interfilare. Dopo due anni di prove, è stato osservato un grande incremento di attività biologica e biodiversità del suolo in tutti i trattamenti, così come un incremento del carbonio organico e dell’azoto nel suolo superficiale. Un risultato molto interessante di tutti e tre le pratiche è stato quello di vedere un aumento dei nematodi predatori e la scomparsa del nematode Xiphinema index (vettore del virus dell’arricciamento fogliare della vite), mentre era sempre presente nella parte di vigneto solamente lavorata. L’apporto di sostanza organica nel suolo contribuisce infatti all’aumento della biodiversità del suolo e molto spesso al contenimento di specie parassite o dannose. I maggiori miglioramenti sul benessere della vite e sulla produzione di uva si sono avuti con l’uso del compost, sebbene 2 anni non siano ancora sufficienti ad ottenere produzioni e qualità paragonabili al resto del vigneto non degradato

Soil management and soil water balance in a mature rainfed olive orchard

An experiment was performed for a 3-year period in a rainfed olive grove located in Southern Italy to evaluate the effect of different soil management techniques on Soil Water Content (SWC). The compared treatments were Sustainable System SS (non-tillage, spontaneous vegetation cover, annual recycling of pruning material) versus Conventional System CS (tillage, no pruning material recycling). Serveys on soil structure and hydrological behaviour were performed. SWC was measured by Bouyoucous blocks placed at different soil depths. Ten years of sustainable soil management increased the storage of rainfall water particularly in the deeper layers. In SS soil macroporosity was higher than CS system and homogeneously distributed along the profile, favouring the vertical water movement down to deeper horizons. In CS the occurrence of soil crusting and compacted layers hindered infiltration and percolation of raifall wate

Influence of soil management on soil physical characteristics and water storage in a mature rainfed olive orchard

Mechanical tillage represents the most common technique of soil management in olive orchards within the Mediterranean Basin. Such practice may result in soil structure degradation which can significantly reduce water infiltration causing runoff and erosion processes. An alternative opportunity is given by the use of cover crops which eliminates most of the disadvantages of conventional tillage. An experiment was carried out from 2007 to 2009 in a mature and rainfed olive grove located in Southern Italy with the aim to evaluate the effect of different soil management techniques on soil structure and soil water content and storage along the profile. The experimental site was characterised by a slope gradient ranging from 0 to 16%. Since 2000, the olive grove was subjected to two different management systems: sustainable system, SS (no-tillage, spontaneous vegetation cover, annual recycling of pruning material) and conventional system, CS (tillage, no recycling of pruning material). Modifications of soil structure induced by the two different management systems were quantified by micromorphometric analysis of macroporosity. Soil hydrological behavior was determined by field saturated hydraulic conductivity (Ksat) measurements. Soil water content was measured at 10/15-day intervals by gypsum resistivity blocks placed in flat and steep areas (summit, backslope, and footslope) of both systems at different soil depths (25, 50, 75, 100, 150 and 200 cm). In the SS soil macroporosity was not very high (about 10%) but homogeneously distributed along the profile which favored the vertical water movement down to deeper horizons. In the CS the occurrence of soil crusting and of compacted layers along the profile hindered infiltration and percolation of rainfall water influencing the soil water content below the 100 cm layer. The SS was able to better store water from rainfall, received during the autumn–winter period, especially in the deepest soil layer (from 100 to 200 cm). This was evident especially in the steep area at the summit position, where the water amounts stored by SS were 45 and 17% higher than those retained by the CS in 2007 and 2009, respectively. During summer such reserves were available for the olive root systems which usually, under the driest conditions, explore the deep soil zone in search of water. Under our experimental conditions, no yield reduction was observed due to the prompt mowing of the spontaneous cover crops. Therefore, the suitable use of cover crops should be communicated to the olive farmers and strongly recommended within agricultural policy strategies for its evident agronomical and environmental benefits (increase of soil organic carbon, soil structure improvement, reduction of soil and water losses, carbon sequestration)

Organic carbon pools and storage in the soil of olive groves of different age

Summary: Compared with annual crop cultivation, tree groves might represent a relevant land-use system to improve C sequestration, but few data are available to support this hypothesis. To evaluate the potential of olive tree (Olea europaea L., 1753) cultivation to store soil organic C (SOC), we assessed (i) the distribution of organic C in active (water-extractable and particulate organic C, WEOC and POC, respectively), intermediate (organic matter associated with stable sand-size aggregates and silt- and clay-size aggregates, SSAs and SCAs, respectively) and passive (organic matter resistant to oxidation, rSOM) pools, (ii) the phenol content of the C pools, (iii) the humic-C distribution of the intermediate C pool and (iv) the stocks of SOC pools in two olive groves of different age (7 years (OG7) and 30 years (OG30)) compared with a nearby site with cereal crops (arable soil, AS). In OG30 the organic C stock of the olive grove was no different from that of the AS, but the distribution of SOC pools changed with the age of the olive groves. The WEOC and POC increased in the Ap horizon of OGs, probably because of the herbaceous cover and distribution of chipped prunings on the soil. There were fewer SSAs in OG7 than AS, possibly because of pedoturbations from deep tillage before the olive trees were established, but they increased in OG30. The increase in SSAs and SCAs in the Bw and BC horizons of OG30 was associated with humic-C and unextractable-C and a smaller phenol content than AS. This suggested that the olive tree roots had a positive role through rhizodeposition and root turnover, which favoured the stabilization of organic matter into aggregates at depth. In contrast to the active and intermediate C pools, the passive C pool did not vary following the change in land use from arable to olive grove. Highlights: Effects of land-use change from arable to olive grove on soil organic C pools and stocks. Soil organic C stock increased from 7- to 30-year-old olive orchard. Olive tree cultivation affected active and intermediate C pools, but not the passive C pool. After 30 years, the olive grove stored an amount of SOC similar to that of the arable system