Farm machinery like water sprinklers (WS) and pesticide sprayers (PS) are becoming quite popular in the agricultural sector. The WS and PS are two distinct types of machinery, mostly powered using conventional energy sources. In recent times, the battery and solar-powered WS and PS have also emerged. With the current WS and PS, the main drawback is the lack of intelligence on water and pesticide use decisions and autonomous control. This paper proposes a novel multi-purpose smart farming robot (MpSFR) that handles both water sprinkling and pesticide spraying. The MpSFR is a photovoltaic (PV) powered battery-operated internet of things (IoT) and computer vision (CV) based robot that helps in automating the watering and spraying process. Firstly, the PV-powered battery-operated autonomous MpSFR equipped with a storage tank for water and pesticide drove with a programmed pumping device is engineered. The sprinkling and spraying mechanisms are made fully automatic with a programmed pattern that utilizes IoT sensors and CV to continuously monitor the soil moisture and the plant’s health based on pests. Two servo motors accomplish the horizontal and vertical orientation of the spraying nozzle. We provided an option to remotely switch the sprayer to spray either water or pesticide using an infrared device, i.e., within a 5-m range. Secondly, the operation of the developed MpSFR is experimentally verified in the test farm. The field test’s observed results include the solar power profile, battery charging, and discharging conditions. The results show that the MpSFR operates effectively, and decisions on water use and pesticide are automated.

Kale, chard, broccoli, peppers, tomatoes, and spinach were grown at various positions within partial shade of a solar photovoltaic array during the growing seasons from late March through August 2017 and 2018. The rows of panels were orientated north-south and tracked east to west during the daylight hours, creating three levels of shade for the plants: 7% of full sun, 55-65% of full sun, and 85% of full sun, as well as a full sun control outside the array. Average daily air temperature at canopy height was within +\- 0.5oC across the shade conditions. Over two field seasons, biomass accumulated in correction with the quantity of photosynthetically active radiation (PAR). Kale produced the same amount of harvestable biomass in all PAR levels between 55% and 85% of full sun. Chard yield was similar in PAR levels 85% and greater. Tomatoes produced the same amount harvestable biomass in all PAR levels greater than 55% of full sun. Broccoli produced significantly more harvestable head biomass at 85% than at full sun irradiance but required at least 85% of full PAR to produce appreciable harvestable material. Peppers generated harvestable fruit biomass at PAR of 55% of full sun or less, but yielded best at 85% of full sun or more. Spinach was sensitive to shade, yielded poorly under low PAR, but increased biomass production as PAR increased. Microclimate variations under PV arrays influence plant yields depending on location within a solar array. Adequate PAR and moderated temperature extremes can couple to produce crop yields in reduced PAR environments similar to and in some cases better than those in full sun. Results from our study showed that careful attention must be made when developing PV arrays over the crops and when choosing which crops to plant among the arrays.

With the increasing demand for new sources of energy, solar power has become an attractive solution for the current energy crisis. Photovoltaic systems have been increasingly used in the form of solar panel arrays. However, despite the numerous advantages of solar technology, the energy-conversion efficiency of solar panels is low. Since these panels are stationary, they are also difficult to deploy and transport and are prone to damages and hindrance. The portable system prototype proposed in this paper can deploy the solar panels easily and retract them with minimal effort based on the Miura origami folding patterns and mechanical rotation of the panels. An active dual-axis solar tracking system based on tilt-and-swing mechanism is added to the system to maximize the efficiency of the solar energy conversion. This inexpensive solar-tracking system is composed of an Arduino microcontroller, photoresistors, and stepper motors. The mechanism of the proposed system is fully explained in this paper and it is demonstrated how this portable system can maximize efficiency of the energy conversion.

Grasslands and croplands located in temperate agro-ecologies are ranked to be the best places to install solar panels for maximum energy production. Therefore, agrivoltaic systems (agricultural production under solar panels) are designed to mutually benefit solar energy and agricultural production in the same location for dual-use of land. However, both livestock farmers and energy companies require information for the application of efficient livestock management practices under solar panels. Therefore, this study was conducted to compare lamb growth and pasture production under solar panels and in open pastures in Corvallis, Oregon in spring 2019 and 2020. Averaged across the grazing periods, weaned Polypay lambs grew at 120 and 119 g/head/d under solar panels and open pastures, respectively in spring 2019 (P=0.90). Although a higher stocking density (36.6 lambs/ha) at the pastures under solar panels was maintained than open pastures (30 lambs/ha) in the late spring period, the liveweight production between grazing under solar panels (1.5 kg ha/d) and open pastures (1.3 kg ha/d) were comparable (P=0.67). Similarly, lambs liveweight gains and liveweight productions were comparable in both pasture types (all P>0.05). The daily water consumption of the lambs in spring 2019 were similar during early spring, but lambs in open pastures consumed 0.72 l/head/d more water than those grazed under solar panels in the late spring period (P<0.01). However, no difference was observed in water intake of the lambs in spring 2020 (P=0.42) The preliminary results from our grazing study indicated that grazing under solar panels can maintain higher carrying capacity of pasture toward summer, and land productivity could be increased up to 200% through combining sheep grazing and solar energy production on the same land. More importantly, solar panels may provide a more animal welfare friendly environment for the grazing livestock as they provide shelter from sun and wind.

Agrivoltaic systems are designed to mutually benefit solar energy and agricultural production in the same location for dual-use of land. This study was conducted to compare lamb growth and pasture production from solar pastures in agrivoltaic systems and traditional open pastures over 2 years in Oregon. Weaned Polypay lambs grew at 120 and 119 g head−1 d−1 in solar and open pastures, respectively in spring 2019 (P = 0.90). The liveweight production between solar (1.5 kg ha−1 d−1) and open pastures (1.3 kg ha−1 d−1) were comparable (P = 0.67). Similarly, lamb liveweight gains and liveweight productions were comparable in both solar (89 g head−1 d−1 ; 4.6 kg ha−1 d−1) and open (92 g head−1 d−1 ; 5.0 kg ha−1 d−1 ) pastures (all P > 0.05) in 2020. The daily water consumption of the lambs in spring 2019 were similar during early spring, but lambs in open pastures consumed 0.72 L/head−1 d−1 more water than those grazed under solar panels in the late spring period (P < 0.01). No difference was observed in water intake of the lambs in spring 2020 (P = 0.42). Over the entire period, solar pastures produced 38% lower herbage than open pastures due to low pasture density in fully shaded areas under solar panels. The results from our grazing study indicated that lower herbage mass available in solar pastures was offset by higher forage quality, resulting in similar spring lamb production to open pastures. Our findings also suggest that the land productivity could be greatly increased through combining sheep grazing and solar energy production on the same land in agrivoltaics systems.

The combined use of solar photovoltaics and agriculture may provide farmers with an alternative source of income and reduce heat stress in dairy cows. The objective of this study was to determine the effects on grazing cattle under shade from a solar photovoltaic system. The study was conducted at the University of Minnesota West Central Research and Outreach Center in Morris, Minnesota on a grazing dairy. Twenty-four crossbred cows were randomly assigned to 2 treatment groups (shade or no shade) from June to September in 2019. The replicated (n = 4) treatment groups of 6 cows each were provided shade from a 30-kW photovoltaic system. Two groups of cows had access to shade in paddocks, and 2 groups of cows had no shade in paddocks. All cows were located in the same pasture during summer. Behavior observations and milk production were evaluated for cows during 4 periods of summer. Boluses and an eartag sensor monitored internal body temperature, activity, and rumination on all cows, respectively. Independent variables were the fixed effects of breed, treatment group, coat color, period, and parity, and random effects were replicate group, date, and cow. No differences in fly prevalence, milk production, fat and protein production, or drinking bouts were observed between the treatment groups. Shade cows had more ear flicks (11.4 ear flicks/30 s) than no-shade cows (8.6 ear flicks/30 s) and had dirtier bellies and lower legs (2.2 and 3.2, respectively) than no-shade cows (1.9 and 2.9, respectively). During afternoon hours, shade cows had lower respiration rates (66.4 breaths/min) than no-shade cows (78.3 breaths/min). From 1200 to 1800 h and 1800 to 0000 h, shade cows had lower body temperature (39.0 and 39.2°C, respectively) than no-shade cows (39.3 and 39.4°C, respectively). Furthermore, between milking times (0800 and 1600 h), the shade cows had lower body temperature (38.9°C) than no-shade cows (39.1°C). Agrivoltaics incorporated into pasture dairy systems may reduce the intensity of heats stress in dairy cows and increase well-being of cows and the efficiency of land use.

The objectives of the thesis were to investigate electrical energy use on dairy farms located in west central Minnesota and to evaluate the effects of shade use by cattle from solar photovoltaic systems. As the push for sustainable food production from consumers continues to grow, food industries and processors are looking for ways they can be more marketable to consumers. Not only do food industries investigate sustainable practices within their own systems, they also push their suppliers to explore ways to lower their farms’ carbon footprints. Measurements of baseline fossil fuel consumption within dairy production systems are scarce. Therefore, there is a need to discern where and how fossil fuel-derived energy is being used within dairy production systems. Baseline energy use data collection is the first step in addressing the demand for a reduced carbon footprint within dairy production systems. Energy use on five Midwest dairy farms was evaluated from July 2018 to December 2019. Through in-depth monitoring of electricity-consuming processes, it was found that electricity use can differ quite drastically in different types of milking systems and farms. Electricity on an annual basis per cow ranged from 400 kWh/cow in a low-input and grazing farm to 1,145 kWh/cow in an automated milking farm. To reduce electrical energy consumption as well as reduce the effects of heat stress in pastured dairy cows, producers may investigate using an agrivoltaic system. Biological effects of internal body temperature, milk production, and respiration rates and behavioral effects of activity, rumination, fly avoidance behaviors, and standing and lying time of the solar shade were evaluated. Treatment groups were shade or no shade of cattle on pasture. The results of this agrivoltaic system suggested that grazing cattle that have access to shade had lower respiration rates and lower body temperatures compared to cattle that do not have access to shade. Electricity used in dairy farms was examined to help producers find areas in their farms that have the potential for reduced energy consumption. Furthermore, the use of an agrivoltaic system on a pasture-based dairy was studied for its shading effects on the health and behavior of dairy cows.

As an answer to the increasing demand for photovoltaics as a key element in the energy transition strategy of many countries—which entails land use issues, as well as concerns regarding landscape transformation, biodiversity, ecosystems and human well-being—new approaches and market segments have emerged that consider integrated perspectives. Among these, agrivoltaics is emerging as very promising for allowing benefits in the food–energy (and water) nexus. Demonstrative projects are developing worldwide, and experience with varied design solutions suitable for the scale up to commercial scale is being gathered based primarily on efficiency considerations; nevertheless, it is unquestionable that with the increase in the size, from the demonstration to the commercial scale, attention has to be paid to ecological impacts associated to specific design choices, and namely to those related to landscape transformation issues. This study reviews and analyzes the technological and spatial design options that have become available to date implementing a rigorous, comprehensive analysis based on the most updated knowledge in the field, and proposes a thorough methodology based on design and performance parameters that enable us to define the main attributes of the system from a trans-disciplinary perspective. The energy and engineering design optimization, the development of new technologies and the correct selection of plant species adapted to the PV system are the areas where the current research is actively focusing in APV systems. Along with the continuous research progress, the success of several international experiences through pilot projects which implement new design solutions and use different PV technologies has triggered APV, and it has been met with great acceptance from the industry and interest from governments. It is in fact a significant potential contribution to meet climate challenges touching on food, energy, agriculture and rural policies. Moreover, it is understood—i.e., by energy developers—as a possible driver for the implementation of large-scale PV installations and building integrated agriculture, which without the APV function, would not be successful in the authorization process due to land use concerns. A sharp increase is expected in terms of number of installations and capacity in the near future. Along this trend, new concerns regarding landscape and urban transformation issues are emerging as the implementation of APV might be mainly focused on the efficiency of the PV system (more profitable than agriculture), with insufficient attention on the correct synergy between energy and food production. The study of ecosystem service trade-offs in the spatial planning and design for energy transition, to identify potential synergies and minimize trade-offs between renewable energy and other ecosystem services, has been already acknowledged as a key issue for avoiding conflicts between global and local perspectives. The development of new innovative systems (PV system technology) and components (photovoltaic devices technology) can enhance the energy performance of selected design options for APV greenhouse typology.

The use of renewable energy in modern greenhouse management is important to achieve efficient and sustainable food supplies for a world with increasing population. This study assessed the performance of a blind-type shading regulator that can automatically rotate semi-transparent photovoltaic (PV) blades installed on the greenhouse roof in response to sunlight variation. The PV blind oriented parallel to the roof partially blocked intense sunlight penetration into the greenhouse, but it transmitted sunlight during cloudy time by turning the blind bearing to be perpendicular to the roof. A stable irradiation environment is therefore producible in the greenhouse under variable sky conditions. Annual operations demonstrated that the blinds’ own generated electrical energy can sustain PV blind operation and produce surplus electrical energy. The PV blind electricity generation and sunlight availability for crops below the PV blind roof were calculated based on a mathematical model developed using theoretical sunlight parameters and the experimentally obtained PV blind system parameters. Assuming cloudless skies and threshold irradiance for blind rotation set at 500 W m−2, 13.0 and 12.3kWh m−2 yr−1 surplus electrical energy can be generated, respectively, by north–south and east–west oriented model greenhouses. Cloudy skies reduce surplus electrical energy production by 50%, but PV blinds can supply greenhouse electrical energy demands partially or completely, depending on the degree of greenhouse electrification. Below the PV blinds, 8–10 MJ m−2 day−1 of insolation is expected to irradiate crops under actual sky conditions. This insolation is sufficient to cultivate major horticultural crops. Regulating the threshold irradiance level for PV blind turning can control the sunlight apportionment ratio for cultivation and electricity generation, thereby enabling sustainable energy–food dual production in a greenhouse.

Wireless sensor networks (WSNs) can be reliable tools in agricultural management. In this work, a low cost, low power consumption, and simple wireless sensing system dedicated for agricultural environments is presented. The system is applicable to small to medium sized fields, located anywhere with cellular network coverage, even in isolated rural areas. The novelty of the developed system lies in the fact that it uses a dummy device as Coordinator which through simple but advanced programming can receive, process, and send data packets from all End-notes to the cloud via a 4G cellular network. Furthermore, it is energy independent, using solar energy harvesting panels, making it feasible to operate in remote, isolated fields. A star topology was followed for the sake of simplification, low energy demands and increased network reliability. The developed system was tested and evaluated in laboratory and real field environment with satisfactory operation in terms of independence, and operational reliability concerning packet losses, communication range (>250m covering fields up to 37ha), energy autonomy, and uninterrupted operation. The network can support up to seven nodes in a 30 min data acquisition cycle. These results confirmed the potential of this system to serve as a viable option for monitoring environmental, soil, and crop parameters.