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Reduction of Plant Protection Products (PPP) has become a priority in agriculture, led by European directives and regulations due to the negative impacts and social awareness that pesticides have raised in the population. In viticulture, the use of copper to control Downy Mildew (Plasmopara viticola) is posing severe problems of soil, water and environment contamination, and European Commission is regulating its use through the EU regulation 2018/1981. A targeted spraying management can be done benefiting from the novel development of variable rate application (VRA) technology for orchard sprayers, resulting in savings of PPP. In this research, the quality of the application in terms of copper deposit in leaves of two VRA strategies where compared versus the conventional strategy performed by the farmer (REF)., This research was developed with funding from the Spanish Ministry of Agriculture Fisheries and Food within the project GOPHYTOVID [contract 2018002001192], and partial funding from the FI-AGAUR grant from the Generalitat de Catalunya (2017 FI_B 00893)., Postprint (published version)

An orchard sprayer prototype running a variable-rate algorithm to adapt the spray volume to the canopy characteristics (dimensions, shape and leaf density) in real-time was designed and implemented. The developed machine was able to modify the application rate by using an algorithm based on the tree row volume (TRV), in combination with a newly coefficient defined as Density Factor (Df). Variations in the canopy characteristics along the row crop were electronically measured using six ultrasonic sensors (three per sprayer side), This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 773718 (OPTimised Integrated pest Management for precise detection and control of plant diseases in perennial crops and open- field vegetables, www.optima-h2020.eu). Bernat Salas received funding for his Ph.D. development from Agència de Gestió D'Ajuts Universitaris I de Recerca (AGAUR) (file N° FI_B 01193), Preprint

Apple scab (Venturia inaequalis) is one of the most endemic diseases that affect apple production worldwide. An accurate management of Plant Protection Products (PPP) together with the use of the latest technologies is one of the objectives of the EU Horizon 2020 OPTIMA project, as part of an integrated pest management (IPM) system. Optimal dose adjustment of PPP in orchards requires an accurate identification of canopy characteristics and a precise sprayer adjustment to distribute the adequate amount of active ingredient and liquid proportionally to the canopy variations. Furthermore, the possibility to use available tools and knowledge to consider the potential variability inside the parcel will lead into a reduction of the amount of PPP, which is a shared objective with the EU Farm to Fork strategy. Within the OPTIMA project a smart orchard sprayer has been developed. The system incorporates 6 ultrasonic sensors (three per side) for canopy characterization. A dedicated program developed using python allows the system to calculate canopy width and canopy density along the row. This information, together with the georeferenced location of the sprayer and the actual forward speed is used to activate the six-solenoid proportional motor-valves controlling the six different spray sections. Information about working pressure and consequently the nozzle flow rate is recorded every 1 s in order to generate the actual application map. The system is based on the adaptation of the Tree Row Volume (TRV) method established by European and Mediterranean Plant Protection Organization (EPPO, 2021) with additional information concerning canopy density. The system is linked with development of EDS (Early Detection System) and DSS (Decision Support System) within the OPTIMA project and the aim at the end of the project will be to link all the three technological developments to achieve a holistic smart sprayer., Postprint (published version)

Apple scab (Venturia inaequalis) is one of the most endemic diseases that affect apple production worldwide. An accurate management of Plant Protection Products (PPP) together with the use of the latest technologies is one of the objectives of the EU Horizon 2020 OPTIMA project, as part of an integrated pest management (IPM) system. Optimal dose adjustment of PPP in orchards requires an accurate identification of canopy characteristics and a precise sprayer adjustment to distribute the adequate amount of active ingredient and liquid proportionally to the canopy variations. Furthermore, the possibility to use available tools and knowledge to consider the potential variability inside the parcel will lead into a reduction of the amount of PPP, which is a shared objective with the EU Farm to Fork strategy. Within the OPTIMA project a smart orchard sprayer has been developed. The system incorporates 6 ultrasonic sensors (three per side) for canopy characterization. A dedicated program developed using python allows the system to calculate canopy width and canopy density along the row. This information, together with the georeferenced location of the sprayer and the actual forward speed is used to activate the six-solenoid proportional motor-valves controlling the six different spray sections. Information about working pressure and consequently the nozzle flow rate is recorded every 1 s in order to generate the actual application map. The system is based on the adaptation of the Tree Row Volume (TRV) method established by European and Mediterranean Plant Protection Organization (EPPO, 2021) with additional information concerning canopy density. The system is linked with development of EDS (Early Detection System) and DSS (Decision Support System) within the OPTIMA project and the aim at the end of the project will be to link all the three technological developments to achieve a holistic smart sprayer., PROJECTE HORIZON 2020-OPTIMA, Postprint (published version)

The presented paper deals with the issue of selecting a suitable system for monitoring the winter wheat crop in order to determine its condition as a basis for variable applications of nitrogen fertilizers. In a four-year (2017-2020) field experiment, 1400 ha of winter wheat crop were monitored using the ISARIA on-the-go system and remote sensing using Sentinel-2 multispectral satellite images. The results of spectral measurements of ISARIA vegetation indices (IRMI, IBI) were statistically compared with the values of selected vegetation indices obtained from Sentinel-2 (EVI, GNDVI, NDMI, NDRE, NDVI and NRERI) in order to determine potential hips. Positive correlations were found between the vegetation indices determined by the ISARIA system and indices obtained by multispectral images from Sentinel-2 satellites. The correlations were medium to strong (r = 0.51-0.89). Therefore, it can be stated that both technologies were able to capture a similar trend in the development of vegetation. Furthermore, the influence of climatic conditions on the vegetation indices was analyzed in individual years of the experiment. The values of vegetation indices show significant differences between the individual years. The results of vegetation indices obtained by the analysis of spectral images from Sentinel-2 satellites varied the most. The values of winter wheat yield varied between the individual years. Yield was the highest in 2017 (7.83 t/ha), while the lowest was recorded in 2020 (6.96 t/ha). There was no statistically significant difference between 2018 (7.27 t/ha) and 2019 (7.44 t/ha)., info:eu-repo/semantics/openAccess

The presented paper deals with the issue of selecting a suitable system for monitoring the winter wheat crop in order to determine its condition as a basis for variable applications of nitrogen fertilizers. In a four-year (2017-2020) field experiment, 1400 ha of winter wheat crop were monitored using the ISARIA on-the-go system and remote sensing using Sentinel-2 multispectral satellite images. The results of spectral measurements of ISARIA vegetation indices (IRMI, IBI) were statistically compared with the values of selected vegetation indices obtained from Sentinel-2 (EVI, GNDVI, NDMI, NDRE, NDVI and NRERI) in order to determine potential hips. Positive correlations were found between the vegetation indices determined by the ISARIA system and indices obtained by multispectral images from Sentinel-2 satellites. The correlations were medium to strong (r = 0.51-0.89). Therefore, it can be stated that both technologies were able to capture a similar trend in the development of vegetation. Furthermore, the influence of climatic conditions on the vegetation indices was analyzed in individual years of the experiment. The values of vegetation indices show significant differences between the individual years. The results of vegetation indices obtained by the analysis of spectral images from Sentinel-2 satellites varied the most. The values of winter wheat yield varied between the individual years. Yield was the highest in 2017 (7.83 t/ha), while the lowest was recorded in 2020 (6.96 t/ha). There was no statistically significant difference between 2018 (7.27 t/ha) and 2019 (7.44 t/ha)., info:eu-repo/semantics/openAccess

The presented paper deals with the issue of selecting a suitable system for monitoring the winter wheat crop in order to determine its condition as a basis for variable applications of nitrogen fertilizers. In a four-year (2017-2020) field experiment, 1400 ha of winter wheat crop were monitored using the ISARIA on-the-go system and remote sensing using Sentinel-2 multispectral satellite images. The results of spectral measurements of ISARIA vegetation indices (IRMI, IBI) were statistically compared with the values of selected vegetation indices obtained from Sentinel-2 (EVI, GNDVI, NDMI, NDRE, NDVI and NRERI) in order to determine potential hips. Positive correlations were found between the vegetation indices determined by the ISARIA system and indices obtained by multispectral images from Sentinel-2 satellites. The correlations were medium to strong (r = 0.51-0.89). Therefore, it can be stated that both technologies were able to capture a similar trend in the development of vegetation. Furthermore, the influence of climatic conditions on the vegetation indices was analyzed in individual years of the experiment. The values of vegetation indices show significant differences between the individual years. The results of vegetation indices obtained by the analysis of spectral images from Sentinel-2 satellites varied the most. The values of winter wheat yield varied between the individual years. Yield was the highest in 2017 (7.83 t/ha), while the lowest was recorded in 2020 (6.96 t/ha). There was no statistically significant difference between 2018 (7.27 t/ha) and 2019 (7.44 t/ha)., info:eu-repo/semantics/openAccess

The presented paper deals with the issue of selecting a suitable system for monitoring the winter wheat crop in order to determine its condition as a basis for variable applications of nitrogen fertilizers. In a four-year (2017-2020) field experiment, 1400 ha of winter wheat crop were monitored using the ISARIA on-the-go system and remote sensing using Sentinel-2 multispectral satellite images. The results of spectral measurements of ISARIA vegetation indices (IRMI, IBI) were statistically compared with the values of selected vegetation indices obtained from Sentinel-2 (EVI, GNDVI, NDMI, NDRE, NDVI and NRERI) in order to determine potential hips. Positive correlations were found between the vegetation indices determined by the ISARIA system and indices obtained by multispectral images from Sentinel-2 satellites. The correlations were medium to strong (r = 0.51-0.89). Therefore, it can be stated that both technologies were able to capture a similar trend in the development of vegetation. Furthermore, the influence of climatic conditions on the vegetation indices was analyzed in individual years of the experiment. The values of vegetation indices show significant differences between the individual years. The results of vegetation indices obtained by the analysis of spectral images from Sentinel-2 satellites varied the most. The values of winter wheat yield varied between the individual years. Yield was the highest in 2017 (7.83 t/ha), while the lowest was recorded in 2020 (6.96 t/ha). There was no statistically significant difference between 2018 (7.27 t/ha) and 2019 (7.44 t/ha).

Wide assimilation of precision agriculture among farmers is currently dependent on the ability to demonstrate its efficiency at the field-scale. Yet, most experiments that compare variable-rate vs uniform application (VRA and UA) are performed in strips, concentrated in a small portion of the field with limited extrapolation to the field scale. A spatiotemporal normalized ratio (STNR) methodology is proposed to evaluate the impact of VRA compared with UA for on-farm trials at the field scale. It incorporates a base year in which the whole plot is managed with UA and consecutive years in which half of the plot is managed with UA and the other half is managed with VRA. Additionally, a novel normalized relative comparison index (NRCI) is presented where the ratios of VRA/UA sub-plots are compared between a base year and a consecutive year, for any measured parameter. The NRCI determines the impact of VRA on variability using statistical measures of dispersion (variability measures) and on performance with statistical measures of central tendency (performance measures). Variability measures with NRCI values lower or higher than 1 indicate VRA management decreased or increased variability. Performance measures with NRCI lower or higher than 1 indicate subplot impairment or improvement, respectively due to VRA management. The methodology was demonstrated on a commercial drip irrigated peach orchard and a wine grape vineyard. NRCI results showed that VRA drip irrigation reduced water status in-field variability but did not necessarily increase yield. The benefits and limitations of the proposed design are discussed.

Variable Rate Application is a method by which the farming inputs are dynamically calibrated to match the optimum soil conditions. This method has the potential to increase agricultural productivity, reduce input costs and make agriculture more sustainable. In this paper, a study has been presented in which variable rate application method has been compared to common rate application method in terms of yields and inputs utilized. The study used an IoT based soil analysis system that was used to obtain real time measurements of soil moisture, temperature and nutrient content to enable data based modifications of input rates and implementation of variable rate application method.

Canopy characterisation is a key factor for the success and efficiency of the pesticide application process in vineyards., This research was developed with partial funding from the FI-AGAUR grant from the Generalitat de Catalunya (2017 FI_B 00893, Preprint

Variable Rate Application is a method by which the farming inputs are dynamically calibrated to match the optimum soil conditions. This method has the potential to increase agricultural productivity, reduce input costs and make agriculture more sustainable. In this paper, a study has been presented in which variable rate application method has been compared to common rate application method in terms of yields and inputs utilized. The study used an IoT based soil analysis system that was used to obtain real time measurements of soil moisture, temperature and nutrient content to enable data based modifications of input rates and implementation of variable rate application method.

Variable Rate Application is a method by which the farming inputs are dynamically calibrated to match the optimum soil conditions. This method has the potential to increase agricultural productivity, reduce input costs and make agriculture more sustainable. In this paper, a study has been presented in which variable rate application method has been compared to common rate application method in terms of yields and inputs utilized. The study used an IoT based soil analysis system that was used to obtain real time measurements of soil moisture, temperature and nutrient content to enable data based modifications of input rates and implementation of variable rate application method.

Variable Rate Application is a method by which the farming inputs are dynamically calibrated to match the optimum soil conditions. This method has the potential to increase agricultural productivity, reduce input costs and make agriculture more sustainable. In this paper, a study has been presented in which variable rate application method has been compared to common rate application method in terms of yields and inputs utilized. The study used an IoT based soil analysis system that was used to obtain real time measurements of soil moisture, temperature and nutrient content to enable data based modifications of input rates and implementation of variable rate application method.

Variable Rate Application is a method by which the farming inputs are dynamically calibrated to match the optimum soil conditions. This method has the potential to increase agricultural productivity, reduce input costs and make agriculture more sustainable. In this paper, a study has been presented in which variable rate application method has been compared to common rate application method in terms of yields and inputs utilized. The study used an IoT based soil analysis system that was used to obtain real time measurements of soil moisture, temperature and nutrient content to enable data based modifications of input rates and implementation of variable rate application method.

Variable Rate Application is a method by which the farming inputs are dynamically calibrated to match the optimum soil conditions. This method has the potential to increase agricultural productivity, reduce input costs and make agriculture more sustainable. In this paper, a study has been presented in which variable rate application method has been compared to common rate application method in terms of yields and inputs utilized. The study used an IoT based soil analysis system that was used to obtain real time measurements of soil moisture, temperature and nutrient content to enable data based modifications of input rates and implementation of variable rate application method.

Variable Rate Application is a method by which the farming inputs are dynamically calibrated to match the optimum soil conditions. This method has the potential to increase agricultural productivity, reduce input costs and make agriculture more sustainable. In this paper, a study has been presented in which variable rate application method has been compared to common rate application method in terms of yields and inputs utilized. The study used an IoT based soil analysis system that was used to obtain real time measurements of soil moisture, temperature and nutrient content to enable data based modifications of input rates and implementation of variable rate application method.

Canopy characterisation is a key factor for the success and efficiency of the pesticide application process in vineyards. Canopy measurements to determine the optimal volume rate are currently conducted manually, which is time-consuming and limits the adoption of precise methods for volume rate selection. Therefore, automated methods for canopy characterisation must be estab-lished using a rapid and reliable technology capable of providing precise information about crop structure. This paper presents regression models for obtaining canopy characteristics of vineyards from unmanned aerial vehicle (UAV) and satellite images collected in three significant growth stages. Between 2018 and 2019, a total of 1400 vines were characterised manually and remotely using a UAV and a satellite-based technology, This research was developed with partial funding from the FI-AGAUR grant from the Generalitat de Catalunya (2017 FI_B 00893)., Postprint (author's final draft)

The aim of this project has been the adaptation and evaluation of a PWM (Pulse Width Modulation) spraying system for the application of plant protection products in 3D crops. This system is already used at field crops with good results. This system in orchards and vineyards should be able to reduce the volumes per hectare applied seeking to optimize the applications and resources provided. In this way, minimize losses due to drift, overlap and under-dosing or over-dosing. This research aims to fulfil the following specific objectives: - Adapting the PWM system on a multi-row sprayer. - The characterization of the different nozzle flow rate changing the Duty Cycle applied at nozzle electrovalves. - In field, evaluation of the PWM system mounted on the multi-row sprayer and comparison versus a conventional application system. The results obtained in this project show the viability about adapting the PWM system on orchards sprayers. Regarding the conventional application, PWM system maintains the characteristics of the application without losing the uniformity of it., L'objectiu d'aquest treball ha estat l'adaptació i avaluació d'un sistema d'aplicació variable PWM (Pulse Width Modulation), actualment utilitzat en cultius herbacis, per a l'aplicació de productes fitosanitaris en cultius arboris, per poder reduir els volums per hectàrea aplicats buscant optimitzar les aplicacions i els recursos aportats. D'aquesta manera minimitzar pèrdues en l'aplicació per deriva, per solapament i per infra-dosificació o sobre-dosificació. El treball està dividit en tres parts: - A la primera part es realitza l¿adaptació del sistema d'aplicació PWM a un equip hidropneumàtic multifila. - A la segona part del treball, un cop adaptat, es realitza la caracterització de cabals en diferents broquets en funció del cicle de treball aplicat a les electrovàlvules controladores dels broquets. - A la tercera i ultima part, un cop caracteritzats els cabals, és la fase d'avaluació del sistema d'aplicació variable PWM a partir de pulsacions respecte del sistema d'aplicació convencional. Els resultats obtinguts en aquest treball demostren la viabilitat del sistema PWM com a sistema d'aplicació variable el qual permet mantenir les característiques de l'aplicació a diferència del sistema d'aplicació convencional., El objetivo de este trabajo ha sido la adaptación y evaluación del sistema de aplicación variable PWM (Pulse Width Modulation), actualmente utilizado en cultivos herbáceos, para la aplicación de fitosanitarios en cultivos arbóreos, para poder reducir los volúmenes por hectárea aplicados para optimizar las aplicaciones y los recursos aportados. De este modo minimizar perdidas en la aplicación por deriva, por solape y por infra dosificación o sobre dosificación. El trabajo se encuentra dividido en tres partes: - En la primera se realiza la adaptación del sistema de aplicación PWM a un equipo hidroneumático multifila. - En la segunda parte del trabajo, una vez adaptado, se realiza la caracterización de los caudales con diferentes boquillas a diferente ciclo de trabajo aplicado en las electroválvulas controladoras de las boquillas. - En la tercera y última parte se evalúa el sistema de aplicación variable a partir de pulsaciones respecto del sistema de aplicación convencional. Los resultados obtenidos en este trabajo demuestran la viabilidad del sistema PWM como sistema de aplicación variable el cual permite mantener las características de la aplicación a diferencia del sistema convencional., Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables, Objectius de Desenvolupament Sostenible::15 - Vida d'Ecosistemes Terrestres

Variable Rate Application is a method by which the farming inputs are dynamically calibrated to match the optimum soil conditions. This method has the potential to increase agricultural productivity, reduce input costs and make agriculture more sustainable. In this paper, a study has been presented in which variable rate application method has been compared to common rate application method in terms of yields and inputs utilized. The study used an IoT based soil analysis system that was used to obtain real time measurements of soil moisture, temperature and nutrient content to enable data based modifications of input rates and implementation of variable rate application method.

In Anbetracht des Kompromisses zwischen der Erzielung des höchsten Gewinns und der geringsten Umweltbelastung ist ein tiefes Verständnis der ökonomischen Folgen der Stickstoff (N) Düngung erforderlich. Die vorliegende Doktorarbeit liefert umfassende Einblicke in (i) die Auswirkungen des standortspezifischen N-Managements (SSNM) auf die Rentabilität und Risikominderung, (ii) die Auswirkungen von Unsicherheiten und Risikoeinflüssen auf optimale N-Düngergaben und (iii) das Potenzial und die Kosten der Vermeidung von Treibhausgas (THG) Emissionen durch N-Düngereduktion. Ein Modellierungsansatz wurde entwickelt, um die Wirkung von Ertrag und Proteingehalt, Wirtschafts- und Risikoauswirkungen sowie THG-Emissionen auf die N-Düngung zu simulieren. Die Ergebnisse der Arbeit zeigen, dass SSNM die Wirtschaftlichkeit verbessert, indem es eine höhere Weizenqualität und damit Preisprämien erzielt. SSNM reduziert das Risiko, die Backqualität nicht zu erreichen, und es gibt keine wesentlichen Nachteile beim Verlustrisikomanagement im Vergleich zum einheitlichen Management. Preisprämien für eine höhere Weizenqualität bieten Anreize für höhere N-Düngergaben. Prämien verflachen die Gewinnfunktion weiter, was unzureichende Argumente für eine Absenkung des N-Inputs aus der Wirtschaftlichkeitssicht liefert, selbst bei einer hohen Risikoaversion der Landwirte. Eine moderate Reduzierung der mineralischen N-Düngung kann die THG-Emissionen bei moderaten Opportunitätskosten mindern. Die THG-Vermeidung durch N-Düngereduktion in einer bestimmten Region kann unter Berücksichtigung kultur- und ertragszonenspezifischer Ertragswirkungen optimiert werden. Insgesamt liefert diese Arbeit wichtige Erkenntnisse über die Chancen und Nachteile der Anpassung der N-Düngergaben. Darüber hinaus leistet sie einen direkten Beitrag zur Identifizierung von kosten- und risikoeffizienten N-Managementoptionen und bildet die Grundlage für effektive politische Ansätze zur THG-Vermeidung durch selektive N-Düngereduktio, Considering the tradeoff between achieving the highest profit and causing the lowest environmental impact, there is a need for a profound understanding of the economic consequences of nitrogen (N) fertilizer application. The present doctoral research provides comprehensive insights into (i) effects of site-specific N management (SSNM) on profitability and risk mitigation; (ii) impacts of uncertainties and risk implications on optimal N fertilizer rates; and (iii) potential and costs of mitigating greenhouse gas (GHG) emissions by N fertilizer reduction. A modelling approach was developed to simulate the response of yield, protein, economic and risk implications, and GHG emissions to N fertilizer application. Findings of the thesis show that SSNM improves profitability by achieving higher grain quality, thus, price premiums. SSNM reduces the risk of not reaching the baking grain quality and poses no considerable disadvantage on downside risk management compared to uniform management. Price premiums for higher wheat quality provide incentives for higher N input rates. Premiums further flatten the profit function, giving insufficient arguments for lowering N input from a farm profitability perspective, even in presence of high risk aversion of farmers. Moderate reduction of mineral N fertilizer can mitigate GHG emissions at moderate opportunity costs. GHG mitigation by N fertilizer reduction in a given region can be optimized considering crop and yield-zone-specific yield responses. Overall, this thesis provides important insights on chances and drawbacks of adjusting N fertilizer rates. Moreover, it makes a direct contribution in identifying cost- and risk-efficient N management options and provides a basis for effective policy approaches to reduce GHG emissions by selective N fertilizer reduction.

The aim of this work wasto evaluate the use of Variable Rate Application technologies based on prescription maps in commercial vineyards with large intra-parcel variability to achieve a more sustainable distribution of Plant Protection Products (PPP)., This research was funded by the project Gophytovid: Optimización del uso de fitosanitarios en viticultura en base a mapas de vigor (Rural development 2014-2020 for Operational Groups), Postprint (published version)

Canopy characteristics are crucial for accurately and safely determining the pesticide quantity and volume of water used for spray applications in vineyards. The inevitably high degree of intraplot variability makes it difficult to develop a global solution for the optimal volume application rate. Here, the design procedure of, and the results obtained from, a variable rate application (VRA) sprayer are presented. Prescription maps were generated after detailed canopy characterization, using a multispectral camera embedded on an unmanned aerial vehicle, throughout the entire growing season in Torrelavit (Barcelona) in four vineyard plots of Chardonnay, Postprint (published version)

In Anbetracht des Kompromisses zwischen der Erzielung des höchsten Gewinns und der geringsten Umweltbelastung ist ein tiefes Verständnis der ökonomischen Folgen der Stickstoff (N) Düngung erforderlich. Die vorliegende Doktorarbeit liefert umfassende Einblicke in (i) die Auswirkungen des standortspezifischen N-Managements (SSNM) auf die Rentabilität und Risikominderung, (ii) die Auswirkungen von Unsicherheiten und Risikoeinflüssen auf optimale N-Düngergaben und (iii) das Potenzial und die Kosten der Vermeidung von Treibhausgas (THG) Emissionen durch N-Düngereduktion. Ein Modellierungsansatz wurde entwickelt, um die Wirkung von Ertrag und Proteingehalt, Wirtschafts- und Risikoauswirkungen sowie THG-Emissionen auf die N-Düngung zu simulieren. Die Ergebnisse der Arbeit zeigen, dass SSNM die Wirtschaftlichkeit verbessert, indem es eine höhere Weizenqualität und damit Preisprämien erzielt. SSNM reduziert das Risiko, die Backqualität nicht zu erreichen, und es gibt keine wesentlichen Nachteile beim Verlustrisikomanagement im Vergleich zum einheitlichen Management. Preisprämien für eine höhere Weizenqualität bieten Anreize für höhere N-Düngergaben. Prämien verflachen die Gewinnfunktion weiter, was unzureichende Argumente für eine Absenkung des N-Inputs aus der Wirtschaftlichkeitssicht liefert, selbst bei einer hohen Risikoaversion der Landwirte. Eine moderate Reduzierung der mineralischen N-Düngung kann die THG-Emissionen bei moderaten Opportunitätskosten mindern. Die THG-Vermeidung durch N-Düngereduktion in einer bestimmten Region kann unter Berücksichtigung kultur- und ertragszonenspezifischer Ertragswirkungen optimiert werden. Insgesamt liefert diese Arbeit wichtige Erkenntnisse über die Chancen und Nachteile der Anpassung der N-Düngergaben. Darüber hinaus leistet sie einen direkten Beitrag zur Identifizierung von kosten- und risikoeffizienten N-Managementoptionen und bildet die Grundlage für effektive politische Ansätze zur THG-Vermeidung durch selektive N-Düngereduktio, Considering the tradeoff between achieving the highest profit and causing the lowest environmental impact, there is a need for a profound understanding of the economic consequences of nitrogen (N) fertilizer application. The present doctoral research provides comprehensive insights into (i) effects of site-specific N management (SSNM) on profitability and risk mitigation; (ii) impacts of uncertainties and risk implications on optimal N fertilizer rates; and (iii) potential and costs of mitigating greenhouse gas (GHG) emissions by N fertilizer reduction. A modelling approach was developed to simulate the response of yield, protein, economic and risk implications, and GHG emissions to N fertilizer application. Findings of the thesis show that SSNM improves profitability by achieving higher grain quality, thus, price premiums. SSNM reduces the risk of not reaching the baking grain quality and poses no considerable disadvantage on downside risk management compared to uniform management. Price premiums for higher wheat quality provide incentives for higher N input rates. Premiums further flatten the profit function, giving insufficient arguments for lowering N input from a farm profitability perspective, even in presence of high risk aversion of farmers. Moderate reduction of mineral N fertilizer can mitigate GHG emissions at moderate opportunity costs. GHG mitigation by N fertilizer reduction in a given region can be optimized considering crop and yield-zone-specific yield responses. Overall, this thesis provides important insights on chances and drawbacks of adjusting N fertilizer rates. Moreover, it makes a direct contribution in identifying cost- and risk-efficient N management options and provides a basis for effective policy approaches to reduce GHG emissions by selective N fertilizer reduction.

Site-specific management of crops represents an important improvement in terms of efficiency and efficacy of the different labours, and its implementation has experienced a large development in the last decades, especially for field crops. The particular case of the spray application process for what are called “specialty crops” (vineyard, orchard fruits, citrus, olive trees, etc.), FI-DGR grant from Generalitat de Catalunya (2018 FI_B1 00083). Research and improvement of Dosaviña have been developed under LIFE PERFECT project: Pesticide Reduction using Friendly and Environmentally Controlled Technologies (LIFE17 ENV/ES/000205), This research was partially funded by the “Ajuts a les activitats de demostració (operació 01.02.01 de Transferència Tecnològica del Programa de desenvolupament rural de Catalunya 2014-2020)” and an FI-DGR grant from Generalitat de Catalunya (2018 FI_B1 00083). Research and improvement of Dosaviña have been developed under the LIFE PERFECT project: Pesticide Reduction using Friendly and Environmentally Controlled Technologies (LIFE17 ENV/ES/000205)., This research was partially funded by the “Ajuts a les activitats de demostració (operació 01.02.01 de Transferència Tecnològica del Programa de desenvolupament rural de Catalunya 2014-2020)” and an FI-DGR grant from Generalitat de Catalunya (2018 FI_B1 00083). Research and improvement of Dosaviña have been developed under LIFE PERFECT project: Pesticide Reduction using Friendly and Environmentally Controlled Technologies (LIFE17 ENV/ES/000205), Postprint (updated version)

This work presents the development of an actual site-specific spraying map of a variable rate sprayer prototype, which works following a prescription map obtained with a UAV. Trials were conducted in Torrelavit (NE Spain) in a representative vineyard of 3 ha of variety Merlot. P, Postprint (published version)

For farmers, the application of Precision Agriculture (PA) technology is expected to lead to an increase in profitability. For society, PA is expected to lead to increased sustainability.The objective of this paper is to determine for a number of common PA practices how much they increase profitability and sustainability. For potato production in The Netherlands, we considered variable rate application (VRA) of soil herbicide, fungicide for late blight control, sidedress N, and haulm killing herbicide. For olive production in Greece, we considered spatially variable application of P and K fertilizer and lime. For each of the above scenarios, we quantified the value of outputs, the cost of inputs, and the environmental costs. This allowed us to calculate profit as well as social profit, where the latter is defined as revenues minus conventional costs minus the external costs of production. Social profit can be considered an overall measure of sustainability. Our calculations show that PA in potatoes increases profit by 21% (420 € ha-1) and social profit by 26%. In olives, VRA application of P, K, and lime leads to a strong reduction in nutrient use and although this leads to an increase in sustainability, it has only a small effect on profit and on social profit. In conclusion, PA increases sustainability in olives and both profitability and sustainability in potatoes.

Although variable rate irrigation (VRI) has been researched and marketed for a number of years, research that quantifies the magnitude of VRI’s potential benefits and that are translatable to unmonitored fields is lacking. The potential reduction in seasonal irrigation is proposed as the criterion for beginning to evaluate the use of VRI to improve agricultural water management when infiltration capacity and plant-available water are spatially variable inside a field. An initial geographic information system study using publicly available geospatial data was conducted to examine soil and topographic properties associated with such variability within 1100 center pivots across 11 counties. The current results only indicate that the extent of variability may be different between counties, but with the acquisition of more accurate and site-specific data as well as the development of a model that enables multi-year comparisons of seasonal irrigation between VRI and uniform irrigation for an individual field, the public could be finally informed about the applicability of VRI by regional assessments of VRI potential and field-specific VRI investment decision tools.

The application of pre-emergence, post-emergence, and burn-down herbicides (i.e., glyphosate) continues to increase as producers attempt to reduce both negative environmental impacts from tillage and input costs from labor, machinery and materials. The use of precision agriculture technologies such as automatic boom section control allows producers to reduce off-target application when applying herbicides. While automatic boom section control provides benefits, pressure differences across the spray boom resulting from boom section actuation can lead to off-rate application errors. Off-rate errors may also result from spray rate controller compensation for ground speed changes and velocity variation across the spray boom during turning movements. This project focuses on quantifying accumulated pesticide application for three fields located in Central Kentucky. GPS coordinates were collected along with nozzle pressure data (at 13 nozzle locations) at one second intervals as the sprayer traversed the study fields. The method previously developed by Luck et al. (2009) was used to calculate coverage areas for the control sections along the spray boom in MS Excel. Nozzle discharge flow rates were estimated from the nozzle pressure data (based on manufacturer calibration information) which was then incorporated into MS Excel to determine the rate of pesticide applied to the fields. Results indicate the majority of each field received application rates at or below the target rate. Only 34.2%, 33.9%, and 22.9% of Fields 1, 2, and 4, respectively, received application rates at the target rate +/- 10% during these postemergence treatments. The goal of this project was develop distribution maps to better understand the effects of boom section control and turning movements on herbicide accumulation.