Search Results (39)

Producing table grapes in altered environments requires an understanding of grapevine physiological responses. This study aimed to determine the physiological reactions of Crimson Seedless/Ramsey vines in response to different water application levels in different micro-climates. Irrigation treatments entailing 100% (W100 = control), 80% (W080), 70% (W070), and 55% (W055) of control volumes were applied to open field (OF) vines and vines underneath overhead plastic covering (OPC). Soil water content (SWC), net photosynthesis (Pn), stem water potential (Ψ_S), transpiration (Tr), micro-climatic variables, and leaf area were measured. The W080 and W070 treatments for OF and OPC, respectively, did not impair physiological processes compared to W100. Conversely, W055 significantly decreased Ψ_S, Pn, and Tr in both trials compared to W100. Underneath OPC, SWC, leaf area, Pn, and Tr values were higher than under OF conditions. Compared to OF, OPC decreased light intensity and increased Ψ_S, albeit resulting in lower photosynthetic water use efficiency. Vines receiving W070 and W055 experienced less stress underneath OPC than under OF conditions, indicating that OPC improves response to water deficit conditions. Additionally, W055 under OPC lowered the average air temperature compared to OF. Water supply reductions of 20% under OF conditions and 30% underneath OPC sufficiently maintained physiological processes. Full article

This study presents a novel federated learning (FL) methodology implemented directly on STM32-based microcontrollers (MCUs) for energy-efficient smart irrigation. To the best of our knowledge, this is the first work to demonstrate end-to-end FL training and aggregation on real STM32 MCU clients (STM32F722ZE), under realistic energy and memory constraints. Unlike most prior studies that rely on simulated clients or high-power edge devices, our framework deploys lightweight neural networks trained locally on MCUs and synchronized via message queuing telemetry transport (MQTT) communication. Using a smart agriculture (SA) dataset partitioned by soil type, 7 clients collaboratively trained a model over 3 federated rounds. Experimental results show that MCU clients achieved competitive accuracy (70–82%) compared to PC clients (80–85%) while consuming orders of magnitude less energy. Specifically, MCU inference required only 0.95 mJ per sample versus 60–70 mJ on PCs, and training consumed ∼70 mJ per epoch versus nearly 20 J. Latency remained modest, with MCU inference averaging 3.2 ms per sample compared to sub-millisecond execution on PCs, a negligible overhead in irrigation scenarios. The evaluation also considers the payoff between accuracy, energy consumption, and latency through the Energy Latency Accuracy Index (ELAI). This integrated perspective highlights the trade-offs inherent in deploying FL on heterogeneous devices and demonstrates the efficiency advantages of MCU-based training in energy-constrained smart irrigation settings. Full article

The use of preemergence herbicides is the primary method of controlling weeds in container-grown ornamental plants, but it may cause injury to common popular ornamentals. The objective of this research was to evaluate the use of overhead irrigation to reduce phytotoxicity in ornamental plants. Dimethenamid-P and flumioxazin were applied at standard label rates to container-grown coneflower (Echinacea purpurea), lady fern (Anthyrium filix-femina), and blue plumbago (Plumbago auriculata). Plants were subjected to one of four irrigation regimes at the time of herbicide treatment, including receiving 1.3 cm of overhead irrigation before treatment, immediately after treatment, both immediately before and after treatment, and no irrigation until the next irrigation cycle resumed at 4 h after treatment. For all three species, irrigation timing had minimal effect on visual injury ratings following treatment with dimethenamid-P, as injury was minimal overall. Severe injury was observed following treatment with flumioxazin, but significant recovery was noted in both lady ferns and echinacea when irrigation was applied immediately after treatment. The results indicate that irrigating plants immediately after treatment could improve crop tolerance to preemergence herbicide applications and should be further investigated as an injury management strategy for container-grown ornamental plants. Full article

The objectives of this study were to determine the effects of irrigation method on the movement of 10 commonly used pesticides in container nursery production. Pesticide transport under three irrigation methods at a nursery engineered to collect irrigation return flow (IRF) from the production surface and subsurface was determined. Pesticide applications occurred three times throughout the study, followed by a 16-day monitoring period. The irrigation applied and surface and subsurface IRF volumes generated from single irrigation events were measured and subsamples of the IRF water were analyzed to assess pesticide presence. Overhead irrigation served as the control with two microirrigation treatments, one applying a fixed amount of water each day and the other scheduled using substrate moisture sensors. Microirrigation reduced irrigation volume by >75% and surface IRF by up to 100%. Subsurface IRF was similarly reduced by microirrigation, yielding 23–47% lower volumes. Pesticides with greater solubilities and lower adsorption coefficients were more mobile than the inversely characterized compounds, particularly in subsurface IRF. The least soluble pesticides had a reduced presence in surface and, to a larger extent, subsurface IRF. Reductions or elimination of surface IRF by using microirrigation reduced the transport of all pesticides by >90%. Pesticides that had a higher solubility were found in subsurface IRF regardless of irrigation method. This study demonstrates the importance of both the irrigation delivery method and pesticide physiochemical properties on the environmental fate of pesticides in nursery settings. Microirrigation can reduce and often eliminate surface IRF, limiting the movement of pesticides regardless of physiochemical properties; whereas, the selection of pesticides that are less soluble can be an effective way to limit the subsurface movement of pesticides, regardless of irrigation method. Full article

Improvements in irrigation water productivity constitute an ongoing effort globally. In California, growers are under regulatory pressure to stabilize groundwater levels and reduce nitrate leaching, partially, by further improvements in irrigation optimization. Evapotranspiration (ET)-based methods can inform crop water requirements and boost irrigation efficiency, but in practice, they can be challenging for farmers to implement, especially in vegetable systems. Irrigation field trials were conducted near Salinas CA in 2018 and 2019 to evaluate the crop coefficient model employed by the CropManage ET-based irrigation decision support system (DSS) for summer cauliflower (Brassica oleracea var. botrytis cv. Symphony) and investigate potential water savings through improved irrigation scheduling. Overhead sprinklers were used for crop establishment, and surface drip was used subsequently. A randomized complete block design was used to administer treatments near 50, 75, 100, and 150% of crop evapotranspiration (ET) during the drip period with an added treatment at 125% in 2019. Water requirement for the 100% treatment was determined by the CropManage DSS model based on crop coefficients derived from fractional canopy cover. Deliveries to remaining treatments were scaled proportionally. The total yield and irrigation productivity were maximized by the 100% treatment both years with total applied water ranging from 275 to 300 mm. At present, the reported water application for summer cauliflower averages 465 mm in the region. Hence, implementing ET-based irrigation scheduling, administered through the CropManage DSS, could reduce water use in summer cauliflower by an average of 30% relative to current practices and serve to enhance groundwater management while maintaining crop returns. Full article

The potential of terminating cover crops with a roller-crimper is of increasing interest. A two-year (2020/21 and 2021/22) study was conducted in Fresno, CA, USA. Five cover crop treatments (rye (Secale cereale L.) alone, ultra-high diversity mix, multiplex cover crop mix, fava bean (Vicia faba L.) + phacelia (Phacelia tanacetifolia Benth.), and rye + field pea (Pisum sativum L.) + purple vetch (Vicia americana Muhl. Ex Willd.)) were planted in November, roller-crimped in April, and silage maize (Zea mays L.) was strip-till planted in the residue in May. Cover crop kill, soil cover by residue, weed cover, amount of organic residue, and silage maize yield were recorded. The roller-crimper resulted in 95 to 100% kill of the cover crops. Soil cover at maize canopy closure (mid-July) was approximately 90% in the rye plots while it was 30 to 70% in the other treatments. The fava bean + phacelia cover crop disintegrated the most rapidly. Weed cover was <5% in all the treatments until maize canopy closure. The cover crops added 6.7 to 14 MT ha⁻¹ of residue. Maize silage yield was similar across the treatments. Therefore, in this study, cover crops were successfully terminated by the roller-crimper, allowing successful strip-till establishment and production of silage maize. Full article

In the traditional surface irrigation system of Vega Baja del Segura (Spain), large amounts of floating waste accumulate at certain points of the river, irrigation channels and drainage ditches, causing malfunctioning of the irrigation network and rising social problems related to the origins of waste. This work proposes a standardized and quick methodology to characterize the floating waste to detect changes in its amount and components. A dataset was created with 477 images of floating plastic items in different environments and was used for training an algorithm based on YOLOv5s. The mean Average Precision of the trained algorithm was 96.9%, and the detection speed was 81.7 ms. Overhead photographs were taken with an unmanned aerial vehicle at strategic points of the river and channels, and its automatic count of floating objects was compared with their manual count. Both methods showed good agreement, confirming that water bottles were the most abundant (95%) type of floating waste. The automatic count reduced the required time and eliminated human bias in image analysis of the floating waste. This procedure can be used to test the reach of corrective measures implemented by local authorities to prevent floating waste in the river. Full article

Early season monitoring of nutrient stress is important in red maple (Acer rubrum L.) and flowering dogwood (Cornus florida L.) to optimize management practices and ensure healthy crop production in containers. Two different irrigation systems (drip and overhead irrigation) were used in this study. Two rates (low and high) of controlled-release fertilizer were used with no fertilizer as a control treatment. Data were recorded for plant height, stem diameter, substrate pH and electrical conductivity (EC), chlorophyll content, normalized difference vegetation index (NDVI), visual observation of plant quality, and leaf nutrient content. The results of this study showed that the increase in plant height and stem diameter was greater among the fertilized maple tree, whereas no differences were observed in the flowering dogwoods for an increase in plant height. NDVI was greater for drip irrigation for both fertilizer rates in both red maples and flowering dogwoods. A positive correlation of 73% to 83% was observed for red maples and 79% to 83% was observed for flowering dogwoods between handheld NDVI and unmanned aerial vehicle-mounted NDVI sensors. In red maple, a high fertilizer rate resulted in greater substrate pH, whereas in flowering dogwood, no differences were observed. Varied responses were observed among the treatments for nutrient content; however, both rates of fertilizer application were sufficient for both tree species. Drip-irrigated red maples had higher nitrogen and phosphorous content, whereas nitrogen content was higher in both irrigation systems in flowering dogwoods. This study provides useful insights into understanding the effect of nutrient stress on tree growth and the application of sensing technology for the monitoring and early detection of nutrient stress in container-grown nursery crops. Full article

Background: Sustainable water management for table grape has the primary goal of optimizing irrigation through Smart Irrigation (SI) approaches, particularly in Mediterranean regions. In addition, extending the shelf life of table grapes through effective cold storage practices is crucial to meet consumer demands year-round. This research examined the journey “from farm to fork” of Sugrathirtyfive variety (Autumn Crisp^® brand), exploring the combined effects of Irrigation Volumes (IV), SO₂-Generating Pads (SGPs) and Cold Storage Duration (CSD) on the quality of grapes. Methods: Normal Irrigation (NI—based on the farmer’s experience) and SI (100% vine evapotranspiration restored) were supplied in 2023 to Sugrathirtyfive variety white table grape, trained to an overhead tendone system. Yield and quality parameters, berry texture, CIELAB colour coordinates, phenolic content, flavonoids, antioxidant activity and sensory attributes were evaluated on grapes subjected to different times and methods of cold storage. Results: SI grapes showed higher Total Soluble Solids (TSSs) and nutraceutical content, as well as improved CIELAB coordinates with interesting improved berry texture parameters. No differences emerged between single- or dual-release SGPs after 15 days (T1) and 40 days (T2) of CSD. Conclusions: Under our cold storage conditions (3 °C, 85% U.R.), 40 days represent the maximum temporal limit for the cold storage of Sugrathirtyfive variety, regardless of IV, provided they are refrigerated with the aid of SGPs. Full article

Greenhouse tomato production faces multiple challenges, including the excessive use of nonrenewable substrates that are difficult to dispose of after use. Currently, most growers propagate tomatoes in rockwool, but there is an increasing demand for sustainable media. The objective of this research was to evaluate sustainable and organic alternatives for greenhouse propagation of tomato seedlings intended for high-wire production. Different organic and inorganic substrates were evaluated in three experiments, using a nutrient solution composed of a complete water-soluble fertilizer. Germination and growth parameters, including height, stem diameter, number of leaves, leaf area, foliar chlorophyll levels (SPAD), and shoot fresh and dry weight, were measured. In the first experiment, which employed overhead irrigation, rockwool, coir, wood fiber–coir mix, medium-grade pine bark, pine bark < 0.64 cm, and pine bark < 0.32 cm were evaluated. Tomato germination was faster and achieved higher percentages with pine bark < 0.64 cm compared to other substrates. However, growth performance was similar or better in coir than in rockwool four weeks after transplantation. For the second experiment with sub-irrigation only, rockwool, coir, wood fiber–coir mix, pine bark < 0.32 cm bark, and peat were evaluated at different container heights. Peat resulted in greater growth across all parameters, followed by wood fiber–coir mix in all container heights, while pine bark had the least growth across all measured parameters. In the third experiment with overhead irrigation, rockwool, wood fiber–coir mix, pine bark < 0.32 cm, and a commercial peat-based mixture were evaluated under different fertilizer rates (electrical conductivity of 1.1 and 2.2 mS·cm⁻¹). Wood fiber–coir mix, peat-based mix, and rockwool were the substrates with the highest values for all evaluated parameters. While all the organic substrates showed potential for use in tomato propagation, pine bark < 0.32 cm bark and wood fiber–coir mix provided the best media for germination. Peat and wood fiber–coir mix showed the best media for subsequent seedling growth and demonstrated potential to be used as substitutes for rockwool. Full article

A potentiometric electronic tongue (ET) for the analysis of well and ditch irrigation water samples is herein proposed. The sensors’ array is composed of six ion-selective electrodes based on plasticized polymeric membranes with low selectivity profiles, i.e., the membranes do not contain any selective receptor. The sensors differ between them in the type of ion-exchanger (sensors for cations or anions) and the plasticizer used in the membrane composition, while the polymeric matrix and the preparation protocol were maintained. The potentiometric response of each sensor towards the main cations (Na⁺, K⁺, Ca²⁺, Mg²⁺) and anions (HCO₃⁻, Cl⁻, SO₄²⁻, NO₃⁻) expected in irrigation water samples was characterized, revealing a fast response time (<50 s). A total of 19 samples were analyzed with the sensor array at optimized experimental conditions, but, also, a series of complementary analytical techniques were applied to obtain the exact ion composition and conductivity to develop a trustable ET. The principal component analysis of the final potential values of the dynamic response observed with each sensor in the array allows for the differentiation between most of the samples in terms of quality. Furthermore, the ET was treated with a linear multivariate regression method for the quantitative determination of the mentioned ions in the irrigation water samples, revealing rather good prediction of Mg²⁺, Na⁺, and Cl⁻ concentrations and acceptable results for the rest of ions. Overall, the ET is a promising analytical tool for irrigation water quality, exceeding traditional characterization approaches (conductivity, salinity, pH, cations, anions, etc.) in terms of overhead costs, versatility, simplicity, and total time for data provision. Full article

Sustainable landscapes provide environmental, social, and financial benefits, with interest and adoption increasing due to environmental awareness. Ornamental ground-cover systems have garnered interest in the landscape due to the reduced need for water, fertilizers, pesticides, and maintenance compared to typical landscapes; however, limited research on groundcover ability to modulate soil conditions or suppress weeds exists. This study explored how ornamental groundcover systems impact the sustainability of landscapes. The effects of ground-cover growth habit (matting; bunching) and irrigation delivery method (micro spray; overhead) on soil temperature, volumetric water content (VWC), and electric conductivity (EC), along with impacts on weed growth, soil microbial communities, and plant coverage, were measured. Soil temperatures were generally lower under groundcover species with a matting growth habit, and to a lesser extent, bunching growth habits, in comparison to the warmer fallow systems. Groundcovers with a matting form led to lower VWC values compared to taxa with other growth habits, particularly when micro-irrigated. Plant form did not significantly influence EC values; however, micro spray irrigated plots had significantly higher EC values, likely attributed to irrigation spray patterns. Micro spray irrigation in tandem with matting growth habit taxa decreased weed density more effectively than taxa with bunching growth habits or groundcovers maintained under overhead irrigation. Selection of groundcover species with greater foliar coverage along with implementing more efficient irrigation practices can decrease soil temperatures, soil moisture, and weed density. Incorporating groundcovers in the landscape can decrease maintenance requirements and water/chemical use, thus increasing sustainability and decreasing environmental consequences. Full article

Seedling species with different architectures, e.g., mean leaf angles, are often subjected to the same irrigation management in forest nurseries, resulting in wasted water and fertilizer and reduced seedling quality. We aimed to evaluate whether irrigation volumes applied to tree seedling species with different leaf angles affect the physiological quality in forest nurseries and, consequently, performance after potting. We submitted nine seedling species with different mean leaf angles to four daily water regimes (8, 10, 12, and 14 mm). In the nursery, the following physiological attributes were considered to assess seedling quality: leaf water potential, daily transpiration rate, SPAD value, chlorophyll a and b, anthocyanins, carotenoids, and total nutrient content. After potting, we evaluated height and stem diameter over 120 days. Leaf angle can be used as a criterion for optimizing irrigation in forest nurseries, avoiding water and fertilizer wastage, and increasing physiological seedling quality. Leaf angle measurements combined with concurrent assessments of leaf traits are helpful in further understanding the effects of leaf angle variation and water regime on seedling quality. For positive leaf angles, an irrigation volume of 8 mm is sufficient to increase physiological seedling quality. Conversely, seedlings with negative leaf angles show the opposite response, requiring the largest irrigation volume (14 mm) to increase physiological seedling quality, except when the mean leaf area is small and concentrated in the upper half of the stem, which facilitates the access of irrigation water to the substrate and thus satisfies seedling water requirements. For all species, up to 120 days after planting in pots, the effect of the irrigation volume that provides greater growth and physiological quality at the end of the nursery phase is not overcome by other irrigation volumes applied. Full article

IoT technology applied to agriculture has produced a number of contributions in the recent years. Such solutions are, most of the time, fully tailored to a particular functional target and focus extensively on sensor-hardware development and customization. As a result, software-centered solutions for IoT system development are infrequent. This is not suitable, as the software is the bottleneck in modern computer systems, being the main source of performance loss, errors, and even cyber attacks. This paper takes a software-centric perspective to model and design IoT systems in a flexible manner. We contribute a software framework that supports the design of the IoT systems’ software based on software services in a client–server model with REST interactions; and it is exemplified on the domain of efficient irrigation in agriculture. We decompose the services’ design into the set of constituent functions and operations both at client and server sides. As a result, we provide a simple and novel view on the design of IoT systems in agriculture from a sofware perspective: we contribute simple design structure based on the identification of the front-end software services, their internal software functions and operations, and their interconnections as software services. We have implemented the software framework on an IoT irrigation use case that monitors the conditions of the field and processes the sampled data, detecting alarms when needed. We demonstrate that the temporal overhead of our solution is bounded and suitable for the target domain, reaching a response time of roughly 11 s for bursts of 3000 requests. Full article

The sessile oak is one of the most significant forest tree species in Europe. This species is vulnerable to various stresses, among which drought and powdery mildew have been the most serious threats. The aim of this study was to determine the influence of irrigation levels (overhead sprinklers) on the damage caused by powdery mildew to Quercus petraea growing in a nursery setting. Four irrigation rates were used: 100%, 75%, 50% and 25% of the full rate. The area of the leaves was measured and the ratio between the dry mass of the roots and the dry mass of the entire plant was calculated after the growing season in years’ 2015 and 2016. Limiting the total amount of water provided to a level between 53.6 mm × m⁻² and 83.6 mm × m⁻², particularly in the months when total precipitation was low (VII and VIII 2015), a supplemental irrigation rate between 3 and 9 mm × m⁻² resulted in a lower severity of oak powdery mildew on leaves and lead to a favorable allocation of the biomass of the sessile oak seedlings to the root system. The severity of infection on oak leaf blades was lower when irrigation rates were reduced. The greatest mean degree of infestation in 2015 was noted in the 100% irrigation rate (14.6%), 75% (6.25%), 50% (4.35%) and 25% (5.47%). In 2016, there was no significant difference between the mean area of leaves infected by powdery mildew depending on the applied irrigation rate. The shoot-root biomass rate showed greater variation under limited irrigation rates. Controlling the irrigation rate can become an effective component of integrated protection strategies against this pathogen. Full article