Research Group on AgroICT and Precision Agriculture

Lleida, Spain

Research Group on AgroICT and Precision Agriculture

Lleida, Spain
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Escola A.,University of Lleida | Rosell-Polo J.R.,University of Lleida | Planas S.,University of Lleida | Gil E.,Polytechnic University of Catalonia | And 4 more authors.
Computers and Electronics in Agriculture | Year: 2013

Discussions in recent decades about dosage models for applying plant protection products in orchards have failed to reach a compromise solution. Furthermore, canopies are spatially variable, and a uniform dose may not be adequate for the entire orchard. Spraying at an adequate volume application rate on a site-specific basis would help reduce the amount of agrochemicals used in the framework of precision horticulture and precision fructiculture.An orchard sprayer prototype running a variable-rate algorithm to adapt the volume application rate to the canopy volume in orchards on a real-time and continuous basis was designed, implemented, and validated. An equivalent prototype was designed for vineyards and described in a companion paper ('Variable rate sprayer. Part 2 - Vineyard prototype: Design, implementation and validation'). The orchard prototype was divided into three parts: the canopy characterization system (using a LiDAR sensor), the controller executing a variable-rate algorithm, and the actuators. The controller determines the intended flow rate by using an application coefficient (required liquid volume per unit canopy volume) to convert canopy volume into a flow rate. The sprayed flow rates are adjusted via electromagnetic variable-rate valves. The goal of the prototype was to keep the actual application coefficients as close as possible to the objective.Strong relationships were observed between the intended and the sprayed flow rates (R2=0.935) and between the canopy cross-sectional areas and the sprayed flow rates (R2=0.926). In addition, when spraying in variable-rate mode, the prototype achieved significantly closer application coefficient values to the objective than those obtained in conventional spraying application mode. © 2013 Elsevier B.V.

Andujar D.,CSIC - Institute of Agricultural Sciences | Escola A.,Research Group on AgroICT and Precision Agriculture | Rosell-Polo J.R.,Research Group on AgroICT and Precision Agriculture | Ribeiro A.,Center for Automatic and Robotic | And 3 more authors.
Precision Agriculture 2015 - Papers Presented at the 10th European Conference on Precision Agriculture, ECPA 2015 | Year: 2015

The multi-angle plant reconstruction obtained from sensors such as Microsoft Kinect creates realistic models. However, a full 3D reconstruction from every angle is not possible at present under field conditions. When an on-the-go measurement is taken, the sensor must be fixed to a vehicle and its best position needs to be determined. The objective of this study was to assess the possibilities of the Microsoft Kinect for Windows v1 sensor to quantify the biomass of poplar trees using different angles from a stationary position, in other words, to explore the best location of the sensor with respect to the trees. For this purpose, readings were obtained by placing the sensor at one meter from the tree, comparing four different view angles: Top view (0°), 45°, perpendicular (90°) and ground (-45°). Good correlations between dry biomass and calculated plant surface area from measured raw data were found. The comparison of the different view angles revealed that top view showed poorer results due to top leaves occluding lower leaves. However, the other views led to good results. Consequently, the Microsoft Kinect for Windows v1 sensor can provide reliable information about crop biomass.

del-Moral-Martinez I.,University of Lleida | Rosell-Polo J.R.,University of Lleida | Rosell-Polo J.R.,Research Group on AgroICT and Precision Agriculture | Company J.,University of Lleida | And 9 more authors.
Sensors (Switzerland) | Year: 2016

The leaf area index (LAI) is defined as the one-side leaf area per unit ground area, and is probably the most widely used index to characterize grapevine vigor. However, LAI varies spatially within vineyard plots. Mapping and quantifying this variability is very important for improving management decisions and agricultural practices. In this study, a mobile terrestrial laser scanner (MTLS) was used to map the LAI of a vineyard, and then to examine how different scanning methods (on-the-go or discontinuous systematic sampling) may affect the reliability of the resulting raster maps. The use of the MTLS allows calculating the enveloping vegetative area of the canopy, which is the sum of the leaf wall areas for both sides of the row (excluding gaps) and the projected upper area. Obtaining the enveloping areas requires scanning from both sides one meter length section along the row at each systematic sampling point. By converting the enveloping areas into LAI values, a raster map of the latter can be obtained by spatial interpolation (kriging). However, the user can opt for scanning on-the-go in a continuous way and compute 1-m LAI values along the rows, or instead, perform the scanning at discontinuous systematic sampling within the plot. An analysis of correlation between maps indicated that MTLS can be used discontinuously in specific sampling sections separated by up to 15 m along the rows. This capability significantly reduces the amount of data to be acquired at field level, the data storage capacity and the processing power of computers. © 2016 by the authors; licensee MDPI, Basel, Switzerland.

Planas S.,University of Lleida | Camp F.,Research Group on AgroICT and Precision Agriculture | Escola A.A.,University of Lleida | Solanelles F.,Research Group on AgroICT and Precision Agriculture | And 2 more authors.
Precision Agriculture 2013 - Papers Presented at the 9th European Conference on Precision Agriculture, ECPA 2013 | Year: 2013

Recently, there have been several attempts to introduce new pesticide dosing methods for fruit orchards and vineyards. However, in Southern Europe, these new methods have not been adopted. This is mainly because farmers lack confidence in the new methods. This lack of confidence partly results from the failure of the new dosing methods to take into account tree leaf density. For this reason, the most common dosing method is the traditional one which is used to control the concentration of the pesticide solution to be sprayed. In this context, farmers tend to spray a greater volume than is necessary and therefore frequently overdose their orchards. A method for estimating the Leaf Area Index was developed. This methodology was then implemented in a decision support system and validated over four seasons, 2009-2012. The decision support system allowed significant reduction in the volume of pesticide sprayed while maintaining the same level of biological efficacy. This system could provide the basis of a universal dose method for pesticide spraying in tree crops.

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