Drone in Precision Viticulture: Advanced Technologies
More and more increasing is the interest that revolves around new technologies in Precision Agriculture. The confirmation of this interest in technologies that offer high precision in the field with the opportunity to improve production and reduce costs of intervention particularly emerged in the wine sector. In the wine industry the process of wine production has evolved from general farming over the entire area to “site-specific” farming. We would therefore like to set out the procedure guidelines of data acquisition, processing and analysis with Drone technology in Precision Viticulture
Precision Viticulture consists in a cyclic process which includes three phases:
1. Observation and data acquisition
2. Data processing, interpretation and evaluation
3. Management plans implementation
1. Observation and data acquisition
The acquisition phase is carried out in remote sensing or better with multi-spectral sensors aboard a Drone. The aerial survey is planned and carried out following aerial photogrammetry techniques totally automatically. The flight provides photos the result of which is a multi-spectral map. The survey in the case of a vineyard is repeated regularly in the different development phases.
Acquisition timing in different development phases
- 1° acquisition (10-20 days after budding end of April – beginning of May)
- 2° acquisition (40-50 days after budding)
- 3° acquisition (70-80 days after budding) – blossoming phase – possibile plant stress, estimated with the NDVI-LAI indexes
- 4° acquisition (100-120 days after budding) – veraison – leaf area development – development of sugars in the grape
- 5° acquisition (130 days after budding) – increased pigmentation – development of color, aroma, polyphenols
General parameters to be considered
- Site location (Latitude-Longitude)
- Temperature analysis
- Site altitute
- Distance from coastline
- Identification of variety and rootstock
From the imagery acquired different Indexes can be extracted most important among which is the vegetation vigor index. The information obtained allows the identification of plants which present problems, water shortages or the presence of pathogens. It is now possible to plan targeted and specific interventions and actions saving time and resources. The maps are an essential resource as they provide cognitive tools whic can be interpreted by the agronomist enable the professional to manage the cultivation most efficiently.
- Maps of vegetative growth
- Mappa of growth speed
- Soil coverage (attributable to the grapevine and/or to the herbaceous cover, important for the estimation of the water content in soil to estimate the water needs of the cultivation)
- Nutritional deficiencies – map of the possible contribution of mineral compost
- Vegetative Vigor NDVI distributuion
- Correlation with the soil characteristics – ability to make correlations between maps: EMI (electromagnetic induction) and NDVI
- Map of the beginning stage of budding (specific and area plant protection)
- Analysis of soil and climatic conditions (thermal and climatic maps, rainfall maps)
- Map of soil characteristics
Factors which can affect the image acquisition period
- Meteorological parameter values, estimated temperature, wind speed, exposure of the area under investigation to be considered
- Distribution of vegetative growth
- Estimation of the indexes related to the content of chlorophyll that allow health estimation of the vegetation and possibly particular stress conditions due to prolonged dry spells and droughts – Normalised Difference Vegetation Index NDVI
- Biophysical indexes based on the Tasseled Cap Transformation theory:
– Greeness, evaluates the health of plants, indicating the force, being sensitive to hydration and the amount of chlorophyll;
– il Brightness, is related to the amount of radiation reflected from a surface, thus it is possible to understand the differences between the different types of soil and distinguish the vegetated areas from soils;
– il Wetness, is linked to the coefficient of humidity of the soil, and allows to discern the different areas, according to the water content of soils.
The change in spectral response of vegetation can serve not only to identify types and different characteristics, but also to recognize geological characteristics and soil of the area. In fact considering the ecological parameters evaluated in this study, such as humidity, temperature and quantity of biomass, you have the ability to recognize different habitats, within the same formations or in situations of heterogeneity of the cover of vegetation.
Article accomplished in cooperation with Doctor Vittoria Pastore Università of Basilicata
The Analist Group Complete Drone Solutions for Precision Farming
How does the Drone for Precision Farming work
Photo shooting witha multi-spectral camera from a Drone
During the flight series of photos are taken. The camera can be set to shoot 1 fps for example.
Image processing to obtain the NDVI Map
The photos taken are fed into Pix4Dmapper, which automatically generates the orthomosaic (it can be geo-located) of thr NDVI.