A NEW TECHNOLOGY FOR THE WINE QUALITY 'AND ACCURACY
A thorough understanding of the subsurface is needed to understand the behavior and take the resulting varietal agronomic measures. An innovative technique, Arp, can operate continuously, saving time and money
Soing Structures and Environment S ocietà investigations geophysical and geological structures for the Environment
The plant vine grows in almost any soil type but the best qualitative and quantitative results are obtained with optimal soil characteristics. The determination of the vocation of a winegrowing area can be achieved through zoning or investigation of soils, designed to determine the geological origin, the soil characteristics and those of the agricultural land itself. This information combined with the topography (slope, elevation, exposure, etc. ..) and climatic conditions allow to prepare the "soil maps" in which the land is classified in the "base unit" in accordance with the wine preparation.
Based on knowledge acquired are classified as unsuitable for viticulture land having the following characteristics:
- excessive moisture, land asphyxiated, subjected to ponding water or shallow groundwater;
- too heavy with clay exceeding 45-50% (Fregoni, M. et al., 1998);
- high lime content, especially in clay soils, where plants are subject to iron chlorosis;
- land surface defined with layer explored by roots below 70 cm - too tired for the next revision.
plant a vineyard is therefore essential to know the mineral composition and physical-chemical soil with numerous influences that these characteristics have on the behavior of the vine variety and especially on the expression of the rootstock.
soil surveys and agricultural precision farming
The term precision farming means farming methods that make use of new technologies to farming techniques adapted to the nature of the soil. To the knowledge of the soil sampling point and distributed according to empirical or randomized patterns have been for a long time the only means of investigation in order to achieve only the estimation of the limits of the soil changes soil. The news today is represented by the use of geophysical methods for innovative knowledge of the characteristics of agricultural soils. In geophysics it is often used as an index of survey parameter inverse to the electrical conductivity, electrical resistivity defined the unit of measure is ohms * m.Per study the electrical resistivity of the soil is the basic principle of the underground injection of a electric current through two current electrodes (A, B), whose potential difference is measured through two potential electrodes (M, N). The innovative character of this analysis is the shift from a fixed point analysis and manual 2-point, about 30,000 measurements per hectare acquired continuously, measuring 20cm each geo-referenced in real time.
Technique ARP (Automatic Resistivity Profiling)
's unique system for acquiring electrical resistivity data quickly and continuously for diagnostic studies in agriculture and precision viticulture is now represented in Europe by the ARP system, used in France by Geocart (Paris), founded in 2001 as a Spin-Off of the CNRS (National Scientific Research Center), which owns intellectual system, protected by a patent. In Italy, under the Partnership established in May 2007, the survey technique is proposed by So.In.G. structures and environment, a company specializing in the development of services in a number of applied geophysics ambiti.L 'current system has three sensors allow to investigate simultaneously at three distinct levels of the ground whose values \u200b\u200bare represented by maps of resistivity, respectively, 0.5m, 1m and 1.7m deep, with readings of both the lateral variations of a single layer, and in depth with the ability to vary the distance between devices misura.Il ARP system, carried by a four-wheel equipped with a digital encoder and system DGPS is capable of acquiring continuous areas of significant extensions in the short term (10-15 acres / day). The electrodes are driven into the ground continuously through the gears that allow the electrodes to be always in contact with the ground. The exact horizontal position (X, Y) and vertical (Z) of the ARP system is achieved by using a differential GPS with accuracy of about 30cm and returned in UTM coordinates.
Figura.1 ARP-equipped with electrodes pulled by Quad Differential GPS and onboard computers.
's use of inquiry in continuous electrical technology ARP allows it to obtain:
a) The identification of homogeneous areas of soil, represented by different values \u200b\u200bresistività.Le homogeneous areas are clearly identified and delimited according to the value of resistivity measured continuously with the ARP method . This method can complement the traditional techniques of field observation and interpretation of aerial photographs provide a further and more rapid investigative tool available to the soil conditions.
b) Reducing the number of samples in direct campo.Il number of samples to be carried out in the field by carottaggi and / or excavations carried out in order to determine the chemical and physical in different soil profiles, can be reduced by knowing the boundaries delimiting the homogeneous areas within the site under investigation. The studies carried out by CRA-ISSDS (Experimental Institute for the Study and soil conservation referent dr. Costantini) in Florence, show that the soil sampling survey led geoelectrical can be reduced (on an area of \u200b\u200b2.5 hectares to 51 to 6 samples), maintaining a good predictive capability for the clay content of soil.
Figura.2 - Scheme of targeted sampling and preparation of paper land on the basis of the homogeneous areas identified by the ARP method.
c) The identification of changes in content ArgillaLo study by CRA-ISSDS of Florence, also points out that the resistivity is significantly correlated with the texture and in particular the fine fraction, the clay, as the latter has a greater specific surface and charge density. The benefits that you can then get ARP survey are found in several stages of production ranging from pre-implantation in the management of the various stages up to the installation of agricultural irrigation systems. Deepening the knowledge of the soil-plant system can then obtain advantages in terms of quality and quantity in the production of precision viticulture.
Figura.3 - Relationship between resistivity (ARP) and clay content of soil determined laboratorio.Grafico obtained from the study done by the CRA-ISSDS of Florence.
d) identification of changes in content idricoIn the changes in resistivity can identify areas with different water content and then the areas with a greater accumulation or more rapid outflow of water for the optimization of the working, manuring and the drainage system of the soil.
method of representing data ARP
In all the investigations conducted by the company as a service So.In.G. structures and environment, are reported in the three maps on the three depths of investigation with the grant are obtained through the service of investigation carried out ARP. For each map are represented as follows: - the values \u200b\u200bin red high resistive (low conductivity), - blue values \u200b\u200bin low resistive (high conductivity), and - in blue, green, yellow and orange intermediate values \u200b\u200bwere increased from low to high resistive . The contours show the topography of measured values.
Figura.4 - Maps of apparent resistivity: ARP-technical survey carried out with the map of the electrical resistivity Apparent
Figure 4 relates to an investigation that affects approximately 3 hectares of vineyard. We distinguish the three depths of investigation show the same color scale. At the same site specific soil profiles performed prior to the survey did not separate these electrical changes as sites of resistance values \u200b\u200bwith very similar (blue-green color in the map). Following this investigation, were made more resistive portions of the profiles shown in red color map that showed the presence of horizons containing calcium carbonate, indicating a significant increase in the electrical resistivity of the soil. The use of three different depths allows us to distinguish two areas showing high values \u200b\u200bof both resistive (red) as described in Figure 4 with the letters (A) and (B): In the top portion (A) resistance values \u200b\u200btend to decrease in depth - index localization of the carbonate horizons in the first 50-100cm Soil: The values \u200b\u200bin the downstream portion (B) remain constant in depth - indicates the presence of carbonate horizons in depth (also satisfied then the presence of sandy horizons) .
The survey ARP that runs as a service, may represent an important new tool knowledge of soil characteristics of the soil, providing an innovative means of analysis available to the precision viticulture.
Anna Morelli, Maria Giovanna Idili, Silvia Gentile April 5, 2008 TN 13 Year 6
