Spatial heterogeneity in the properties of hydroponic wheat fodder and its sustainability.

This study was conducted to determine the heterogeneity of the quantitative and qualitative properties of fodder growth in cultivated hydroponic wheat fodder (HWF) in the growth tray area and to evaluate the impact on the environment. HWF was grown using nutrient film technique. Yield productivity (YP) of HWF in the growth tray area was divided into four characteristic zones (A, B, C, and D). The most fertile zone A accounted for only 22.3 ± 4.2% of the entire growth tray area, while zone B accounted for 44.7 ± 4.0%. Zones C and D, which accounted for 28.0 ± 1.3% and 5.0 ± 0.3% area, respectively, pose various problems for forage production, i.e., they negatively impact the quantity and quality of HWF, as well as the environment. If all areas in the growth tray support the highest fodder YP (zones A and B), then one kg of dry wheat grains will yield about 6-7 kg of HWF (consisting of 10.7-12.4% dry matter, 17.3-17.5% crude protein, 1.8-2.3% starch, 13.1-14.4% crude fiber, and 4.5-4.6% ether extract). Results of life cycle assessment show that HWF with YPs of 3-5 kg from one kg of dry grains (zones C and D) has the most adverse impact on the environment (150 and 220 kg CO2eq t-1). Under optimum conditions (zone A), CO2eq varied from 94 to 115 kg CO2eq t-1 of feed. Environmentally, HWF production had the most impact on marine aquatic ecotoxicity, abiotic depletion, global warming potential, and freshwater aquatic ecotoxicity.

Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (Solanum lycopersicum L.) Seedlings in Hydroponic Systems.

Seven auxin-producing endophytic bacterial strains (Azospirillum spp., Methylobacterium symbioticum, Bacillus spp.), and two different combinations of these strains were used to verify their influence on tomato during germination and development in hydroponic conditions where, as a novelty for Canestrino di Lucca cultivar, endophytic bacteria were inoculated. To emphasize the presence of bacterial auxins in roots and stems of seedlings, both in situ staining qualitative assessment and quantitative analysis were carried out. Moreover, hypogeal and epigeal growth of the plantlets were measured, and correlation analyses were conducted to examine the relationship between the amount of indolacetic acid (IAA) produced by the bacterial strains and root and stem parameters. Plantlets treated with microbial inoculants showed a significant increase in the survival rate compared to the control treatment. The best results as IAA producers were from Azospirillum baldaniorum Sp245 and A. brasilense Cd, which also induced significant root growth. On the other hand, Bacillus amyloliquefaciens and B. licheniformis induced the best rates in stem growth. These findings highlight the potential for using endophytic bacterial strains in a hydroponic co-cultivation system that enables inoculating plantlets, at an early stage of growth (5 days old).

Excess copper promotes an increase in the concentration of metabolites in Tridax procumbens L.

The study investigated the effects of cultivating Tridax procumbens in hydroponic conditions with different concentrations of copper ions, aiming to understand the physiological changes and the impact on the biosynthesis of secondary metabolites. The treatments consisted of a completely randomized design, with five increasing concentrations of copper (T0 = 0.235, T1 = 12.5, T2 = 25, T3 = 50, T4 = 100 µmol L-1 of Cu), under controlled conditions for 36 days. Analysis of bioactive compounds in leaves was performed by HPLC-DAD and ESI-MS. Several phenolic compounds, alkaloids, phytosterols and triterpenoids were identified, demonstrating the plant's metabolic plasticity. The highest dose of copper (100 µmol L-1) significantly promoted voacangine, the most predominant compound in the analyses. Notably, 66.7% of the metabolites that showed an increase in concentration, were phenolic compounds. Furthermore, treatments with 12.5 and 25 µmol L-1 of copper were identified as promoting the biosynthesis of phytosterols and triterpenoids. These biochemical adaptations can play a fundamental role in the survival and development of plants in environments contaminated by metals, and from this it is possible to determine cultivation techniques that maximize the biosynthesis of the compound of interest.

Effect of hydroponic barley fodder on growth performance, carcass yield and carcass quality of cobb 500 broilers.

This study was conducted to evaluate the effect of hydroponic barley fodder supplementation on growth performance, carcass yield and carcass quality of Cobb 500 broilers. An accustomed proper feeding and brooding have been given to the chicks for up to three weeks of age. After three weeks, 144 three-week-old birds were randomly assigned to four treatments and replicated three times with 12 chicks per replication in a completely randomized design. Treatments were arranged as follows; T1: Home formulated Broiler diet (control group), T2: Home formulated Broiler diet +3.5 % hydroponic barley fodder, T3: Home formulated Broiler diet +7 % hydroponic barley fodder, and T4: Home formulated Broiler diet +10.5 % hydroponic barley fodder. The proximate analysis revealed that, hydroponic barley fodder contained 15.63 % crude protein, 10.6 crude fiber, and 4.04 ether extract. Increasing the level of hydroponic barley fodder was associated with an improvement of both growth performance and weight of carcass components of Cobb 500 broilers. Higher average daily feed intake (112.72 g/bird), daily body weight gain (56.37 g/bird), total body weight gain (1579.39 g/4 weeks) were obtained from T4 (home formulated feed +10.5 % HBF). Similarly, higher feed conversion efficiency (1.99 g of feed/g of weight gain) was recorded in T4. Hydroponic barley fodder had no significant (P > 0.05) effect on the mortality rate and carcass quality of broiler chickens. Economically, the highest net return was obtained from birds fed on T4 (Home formulated Broiler diet +10.5 % hydroponic barley fodder). In conclusion, supplementing hydroponic barley fodder up to 10.5 % improves carcass characteristics and result higher net income compared to other treatments. The current study recommended that further investigation like inclusion and substitution trial should be conducted to determine whether hydroponic barley fodder can replace expensive poultry ration ingredients.

The nitrogen-sulfur ratio of acid rain modulates the leaf- and root-mediated co-allelopathy of Solidago canadensis.

The majority of allelopathic studies on invasive plants have focused primarily on their leaf-mediated allelopathy, with relatively little attention paid to their root-mediated allelopathy, especially co-allelopathy mediated by both leaves and roots. It is conceivable that the diversified composition of acid rain may influence the allelopathy of invasive plants. This study aimed to evaluate the leaf and root-mediated co-allelopathy of the invasive plant Solidago canadensis L. under acid rain with different nitrogen-sulfur ratios (N/S) on Lactuca sativa L. via a hydroponic incubation. The root-mediated allelopathy of S. canadensis was found to be more pronounced than the leaf-mediated allelopathy of S. canadensis with nitric acid at pH 4.5, but the leaf-mediated allelopathy of S. canadensis was observed to be more pronounced than the root-mediated allelopathy of S. canadensis with sulfuric-rich acid at pH 4.5. The leaf and root-mediated co-allelopathy of S. canadensis was more pronounced than that of either part alone with sulfuric acid at pH 5.6 and nitric acid at pH 4.5, but not with nitric-rich acid at pH 4.5 and sulfuric-rich acid at pH 4.5. Sulfuric acid and sulfuric-rich acid with stronger acidity intensified the leaf-mediated allelopathy of S. canadensis. Nitric acid and nitric-rich acid attenuated the leaf-mediated allelopathy of S. canadensis, and most types of acid rain (especially nitric acid and nitric-rich acid) also attenuated the root-mediated allelopathy of S. canadensis and the leaf and root-mediated co-allelopathy of S. canadensis. Sulfuric acid and sulfuric-rich acid produced a more pronounced effect than nitric acid and nitric-rich acid. Hence, the N/S ratio of acid rain influenced the allelopathy of S. canadensis under acid rain with multiple N/S ratios.

MyC Factor Analogue CO5 Promotes the Growth of Lotus japonicus and Enhances Stress Resistance by Activating the Expression of Relevant Genes.

The symbiotic relationship between arbuscular mycorrhizal fungi (AMF) and plants is well known for its benefits in enhancing plant growth and stress resistance. Research on whether key components of the AMF colonization process, such as MyC factors, can be directly utilized to activate plant symbiotic pathways and key functional gene expression is still lacking. In this paper, we found that, using a hydroponics system with Lotus japonicus, MyC factor analogue chitin oligomer 5 (CO5) had a more pronounced growth-promoting effect compared to symbiosis with AMF at the optimal concentration. Additionally, CO5 significantly enhanced the resistance of Lotus japonicus to various environmental stresses. The addition of CO5 activated symbiosis, nutrient absorption, and stress-related signaling pathways, like AMF symbiosis, and CO5 also activated a higher and more extensive gene expression profile compared to AMF colonization. Overall, the study demonstrated that the addition of MyC factor analogue CO5, by activating relevant pathways, had a superior effect on promoting plant growth and enhancing stress resistance compared to colonization by AMF. These findings suggest that utilizing MyC factor analogues like CO5 could be a promising alternative to traditional AMF colonization methods in enhancing plant growth and stress tolerance in agriculture.

Can Trichoderma harzianum be used to enhance the yield and nutrient uptake of Lactuca sativa cv "Lollo Rosso" in floating systems?

An experiment was performed to evaluate the effect of Trichoderma harzianum MVT801 combined with different ratios of nutrient solution (NR) (25%, 50%, and 100%) on the growth and physiological traits of Lactuca sativa "Lollo Rosso" plants cultivated in floating systems. Inoculation of lettuce plants with T. harzianum MVT801 (T1) in a floating system improves biometric properties, photosynthetic parameters, and nutrient uptake compared with uninoculated treatment (T0). The results clearly showed that in T1, despite a 50% reduction in the ratio of nutrient solution, no significant difference was observed in the growth and photosynthesis characteristics and nutrient uptake in L. sativa "Lollo Rosso" leaves compared with a complete nutrient solution treatment (100%), which is one of the notable results of this study. In this regard, the highest yield was observed in T1NR50 (inoculated with fungi and 50% of the nutrient solution) and T1NR100 (inoculated with fungi and complete nutrient solution) treatments. Also, the highest concentrations of phosphorus and potassium in "Lollo Rosso" leaves were observed in T1NR50 and T1NR100 treatments. Accordingly, the use of T. harzianum in floating lettuce cultivation could be recommended to increase crop productivity and reduce the use of chemical fertilizers.

Replacing maize silage with hydroponic barley forage in lactating water buffalo diet: impact on milk yield and composition, water and energy footprint, and economics.

This study investigated the feasibility of integrating hydroponic barley forage (HBF) production into dairy ruminant production, focusing on its effect on milk yield and components, energy and water footprints, and economic implications. Maize silage (MS) was used as a benchmark for comparison. The research was conducted on a water buffalo dairy farm equipped with a fully automated hydroponic system producing approximately 6,000 kg/d of HBF as fed (up 1,000 kg/d on DM basis). Thirty-three lactating water buffaloes were assigned to 3 dietary treatments based on the level of MS or HBF in the diet: D0 (100% MS), D50 (50% MS and 50% HBF), and D100 (100% HBF). The feeding trial lasted 5 weeks plus a 2-week adaptation period during which each cow underwent a weighing, BCS scoring, recording of milk yield and components, including somatic cell count and coagulation characteristics. Based on the data obtained from the in vivo study, the water and energy footprints for the production of MS and HBF and buffalo milk, as well as income over feed cost, were evaluated. Complete replacement of MS with HBF resulted in a slight increase in milk yield without significant impact on milk component. The resource footprint analysis showed potential benefits associated with HBF in terms of water consumption. However, the energy footprint assessment showed that the energy ratio of HBF was less than 1 (0.88) compared with 11.89 for MS. This affected the energy efficiency of milk yield in the 3 diets, with the D50 diet showing poorer performance due to similar milk yield compared with D0, but higher energy costs due to the inclusion of HBF. The production cost of HBF was about 4 times higher than that of farm-produced MS, making feed costs for milk yield more expensive. Nevertheless, HBF can potentially improve income over feed costs if it increases milk yield enough to offset its higher production costs. Overall, the results suggest that the current practice of using HBF to replace high quality feedstuffs as concentrates is likely to result in energy and economic losses.

Implementation of a botanical bioscrubber for the treatment of indoor ambient air.

This study explores the effectiveness of a botanical bioscrubber system using Golden Pothos (Epipremnum aureum) in hydroponic setups to mitigate common indoor atmospheric pollutants. Over a 100-day operation, levels of SO2, NO2, O3, TVOC, CO, CO2, PM10, and PM2.5 were monitored, with a significant reduction in carbon-based compounds and particulate matter-. Notably, CO2 and PM2.5 removal efficiencies were significantly correlated with the foliar area, suggesting that the interaction between pollutants and plant leaves plays a crucial role in the phytoremediation process. In contrast, CO, PM10, and TVOC exhibited varied removal efficiencies, hinting the involvement of mechanisms beyond leaf interaction, such as adsorption in irrigation water or root system capture. The absence of significant correlations for PM10 emphasized the need for further investigation into alternative removal processes, potentially mediated by the root system. Overall, our findings suggest that botanical bioscrubbers, particularly those utilizing Golden Pothos, hold promise for indoor air purification through plant-based systems.

The impact of benzoic acid and lactic acid on the treatment efficiency and microbial community in the sulfur autotrophic denitrification process.

Nitrate poses a potential threat to aquatic ecosystems. This study focuses on the sulfur autotrophic denitrification mechanism in the process of water culture wastewater treatment, which has been successfully applied to the degradation of nitrogen in water culture farm effluents. However, the coexistence of organic acids in the treatment process is a common environmental challenge, significantly affecting the activity of denitrifying bacteria. This paper aims to explore the effects of adding benzoic acid and lactic acid on denitrification performance, organic acid removal rate, and microbial population abundance in sulfur autotrophic denitrification systems under optimal operating conditions, sulfur deficiency, and high hydraulic load. In experiments with 50 mg·L-1 of benzoic acid or lactic acid alone, the results show that benzoic acid and lactic acid have a stimulating effect on denitrification activity, with the stimulating effect significantly greater than the inhibitory effect. Under optimal operating conditions, the average denitrification rate of the system remained above 99%; under S/N = 1.5 conditions, the average denitrification rate increased from 88.34% to 91.93% and 85.91%; under HRT = 6 h conditions, the average denitrification rate increased from 75.25% to 97.79% and 96.58%. In addition, the addition of organic acids led to a decrease in microbial population abundance. At the phylum level, Proteobacteria has always been the dominant bacterial genus, and its relative abundance significantly increased after the addition of benzoic acid, from 40.2% to 61.5% and 62.4%. At the genus level, Thiobacillus, Sulfurimonas, Chryseobacterium, and Thermomonas maintained high population abundances under different conditions. PRACTITIONER POINTS: Employing autotrophic denitrification process for treating high-nitrate wastewater. Utilizing organic acids as external carbon sources. Denitrifying bacteria demonstrate high utilization efficiency towards organic acids. Organic acids promote denitrification more than they inhibit it. The promotion is manifested in the enhancement of activity and microbial abundance.

Enhancing Salt Stress Tolerance in Tomato (Solanum lycopersicum L.) through Silicon Application in Roots.

Soil salinization poses a significant threat to agricultural productivity, necessitating innovative agronomic strategies to mitigate its impact. This study focuses on improving salt stress resistance in tomato plants through the application of silicon (Si) in roots. A greenhouse experiment was carried out under normal conditions (control, and 1 and 4 mM Si) and under salinity stress (salt control, and 1 and 4 mM Si). Various parameters were analyzed in leaves and roots. Under normal conditions, tomato plants grown in non-saline conditions exhibited some toxicity when exposed to Na2SiO3. As for the experiments under salt stress conditions, Si mitigated oxidative damage, preserving root cell membrane integrity. The concentration of malondialdehyde was reduced by 69.5%, that of proline was reduced by 56.4% and there was a 57.6% decrease in catalase activity for tomato plants treated with 1 mM Si under salt stress. Furthermore, Fe uptake and distribution, under salt conditions, increased from 91 to 123 mg kg-1, the same concentration as that obtained for the normal control. In all cases, the lower dose produced better results under normal conditions than the 4 mM dose. In summary, this research provides a potential application of Si in non-fertigated crop systems through a radicular pathway.

Uptake, accumulation, translocation and transformation of seneciphylline (Sp) and seneciphylline-N-oxide (SpNO) by Camellia sinensis L.

Pyrrolizidine alkaloids (PAs) and their N-oxide (PANOs), as emerging environmental pollutants and chemical hazards in food, have become the focus of global attention. PAs/PANOs enter crops from soil and reach edible parts, but knowledge about their uptake and transport behavior in crops is currently limited. In this study, we chose tea (Camellia sinensis L.) as a representative crop and Sp/SpNO as typical PAs/PANOs to analyze their root uptake and transport mechanism. Tea roots efficiently absorbed Sp/SpNO, utilizing both passive and active transmembrane pathways. Sp predominantly concentrated in roots and SpNO efficiently translocated to above-ground parts. The prevalence of SpNO in cell-soluble fractions facilitated its translocation from roots to stems and leaves. In soil experiment, tea plants exhibited weaker capabilities for the uptake and transport of Sp/SpNO compared to hydroponic conditions, likely due to the swift degradation of these compounds in the soil. Moreover, a noteworthy interconversion between Sp and SpNO in tea plants indicated a preference for reducing SpNO to Sp. These findings represent a significant stride in understanding the accumulation and movement mechanisms of Sp/SpNO in tea plants. The insights garnered from this study are pivotal for evaluating the associated risks of PAs/PANOs and formulating effective control strategies.

Occurrence and Risk Assessment of Pesticides, Phthalates, and Heavy Metal Residues in Vegetables from Hydroponic and Conventional Cultivation.

Hydroponic cultivation of fresh produce is gaining popularity worldwide, but few studies have provided a comparative assessment of hydroponic and conventional soil-based vegetables. In this study, we analyzed a series of hazardous chemicals, including 120 pesticides, 18 phthalates (PAEs), and 2 heavy metals (lead and cadmium) in four vegetable commodities (lettuces, celeries, tomatoes, and cucumbers) from hydroponic and conventional soil-based cultivation. Our study showed that at least one pesticide was present in 84% of the conventionally grown samples, whereas only 30% of the hydroponic samples contained detectable pesticide residues. Regarding the total PAE concentrations, there was no significant difference between conventional and hydroponic vegetables. The lead and cadmium residues in conventionally cultivated vegetables were significantly higher than in those produced from hydroponic cultivation. Lead is the primary heavy metal pollutant across all vegetable samples. The hazard index (HI) values of the hydroponic and conventional vegetables were 0.22 and 0.64, respectively. Since both values are below one, the exposure to these hazardous chemicals through consumption of the studied vegetables may not pose a significant health risk. The HI values also suggested that the health risks of eating hydroponic vegetables are lower than for conventional soil-based vegetables.

Removal of high lead concentration by hydroponic cultures of normal and transformed plants of Scirpus americanus Pers.

Lead is a very toxic metal which affects human health. An alternative to remove it from contaminated water is the use of macrophytes, as Scirpus americanus Pers. This species is tolerant to salt and metals and has high biomass. The present research analyzed the capacity of hydroponic cultures of normal and transgenic plants (line T12) from S. americanus to remove high concentrations of lead. The antioxidant response of plants to metal exposure was also measured. The MINTEQ3.1 program was used to define the media composition in order to have the metal available to the plants. According to MINTEQ3.1 predictions, sulfate, phosphate, and molybdenum must be removed from the medium to avoid lead precipitation. Therefore, the plants were maintained in a modified Hoagland solution containing 100, 250, and 400 mg/L lead. The presence of metal did not affect the growth of roots and stems at all concentration tested. The normal and T12 plants accumulated 69,389 mg/kg and 45,297 mg/kg lead, respectively, and could be considered hyperaccumulators. Plant tolerance to lead mainly involved an increase in superoxide dismutase activity and glutathione accumulation. The bioconcentration factor indicated that S. americanus plants bioconcentrated between 192 and 300 times the metal; thus, S. americanus could be used for phytoremediation of water contaminated with a high concentration of lead.

Automatic nutrient estimator: distributing nutrient solution in hydroponic plants based on plant growth.

Background: The primary objective is to address the specific needs of plants at different growth stages by delivering precise nutrient concentrations tailored to their developmental requirements. Challenges such as uneven nutrient distribution, fluctuations in pH and electrical conductivity, and inadequate nutrient delivery pose potential hindrances to achieving optimal plant health and yield in hydroponic systems. By overcoming these challenges, the hydroponic farming community aims to enhance the accuracy of nutrient dosing, streamline automation processes, and minimize resource wastage. Hydroponics, a cultivation technique without soil, facilitates the growth of organic vegetation while concurrently minimizing water use and eliminating the necessity for pesticides. In order to achieve effective cultivation of hydroponic plants, it is essential to maintain a controlled environment that encompasses essential factors such as temperature, carbon dioxide (CO2) levels, oxygen availability, and appropriate lighting conditions. Additionally, it is crucial to ensure the provision of vital nutrients to maximize output and productivity. Due to the demanding nature of a hydroponic farmer's schedule, it is necessary to minimize the amount of time dedicated to nutrient management, as well as pH and EC adjustments. Methods: In order to determine and deliver the proper amount of vital nutrients, such as nitrogen, phosphorus, and potassium, based on the plant growth stage, we presented an automatic hydroponic nutrient estimator in this system. We noticed that the plant's nutrient consumption varies depending on its stage of growth according to plant psychology. Four peristaltic pumps with the necessary sensors are controlled by an Arduino board in the suggested system. Both filling and draining the water are done using each pump. To identify the plant stage, we apply the Plant Growth Stage Identification algorithm to encompass the seedling, vegetative, flowers, and fruit stages. Results: The experimental results reveal that the Growth Stage Identification algorithm obtains 97.5% accuracy for the first 5 weeks with 1,715 ppm of nutrition ingestion, identifying the vegetative state. The flowering stage is identified with 97.5% accuracy in the 6-9th week with 2,380 ppm of nutrition consumption, and the fruiting location is determined with 99.4% accuracy in the last 10-15th week with 2,730 ppm of nutrition consumption.

Exploring Trachyspermum ammi and Foeniculum vulgare in Hydroponic System and Compare its Chemical Constituents with Soil-Based Method: A Prospective in Agriculture.

BACKGROUND: The forthcoming problems will be of food, and soil due to environmental alteration, growing populations, pollution, and exhaustion of natural resources among other factors. Hydroponic farming has the capacity to alleviate the intimidation of these con-cerned issues in the agricultural system. Hydroponics is recommended as an alternative way to enhance product yield compared to conventional agriculture. OBJECTIVE: The present study aimed to determine the different growth parameters and constituents of soil-grown and hydroponically grown Trachyspermum ammi and Foeniculum vulgare for the first time, which could be a patentable in future. METHODS: In this study, extraction was carried out by maceration method using methanol as a solvent whereas, growth parameters were performed by the leaves number, plant height, and leaf area. Chlorophyll content was also performed in both sources. Further, a comparison of chemical constituents from different sources was analyzed by GC-MS. RESULTS: The bioactive components in hydroponically grown T. ammi were found more as compared to soil-grown T. ammi. The GC-MS analysis revealed the presence of various compounds in the methanolic extract of plant materials. CONCLUSION: Hence, hydroponics could be an alternative in agriculture and this system is now accepted globally. This method provides diverse perspectives for farmers to harvest high-yield, better quality, and enhanced bioactive compounds.

Hydroponic barley supplementation fed with high protein diets improves the production performance of lactating dairy cows.

The study investigated the effects of dietary protein level and the inclusion of hydroponic barley sprouts (HB) on lactation performance, blood biochemistry and N use efficiency in mid-lactation dairy cows. Treatments were arranged in a 2 × 2 factorial design with 2 crude protein (CP) levels [16.8% and 15.5% of dry matter (DM)], with HB (4.8% of DM, replacing 4.3% of alfalfa hay and 0.5% of distillers dried grains with solubles (DDGS)) or without HB. Forty-eight multiparous Holstein dairy cows (146 ± 15 d in milk, 40 ± 5 kg/d of milk) were randomly allocated to 1 of 4 diets: high protein diet (16.8% CP, HP), HP with HB (HP+HB), low protein diet (15.5% CP, LP), or LP with HB (LP+HB). An interaction between CP × HB on dry matter intake (DMI) was detected, with DMI being unaffected by HB inclusion in cows fed the high CP diets, but was lower in cows fed HB when the low CP diet was fed. A CP × HB interaction was also observed on milk and milk protein yield, which was higher in cows fed HB with HP, but not LP. Inclusion of HB also tended to reduce milk fat content, and feeding HP resulted in a higher milk protein and milk urea N content, but lower milk lactose content. Feed efficiency was increased by feeding HP or HB diets, whereas N efficiency was higher for cows fed LP or HB diets. There was an interaction on the apparent total-tract digestibility of DM and CP, which was higher when HB was fed along with HP, but reduced when fed with LP, whereas the digestibility of ADF was increased by feeding low protein diets. In conclusion, feeding a low protein diet had no adverse effect on cow performance, while feeding HB improved milk and milk component yield, and N efficiency when fed with a high CP diet, but compromised cow performance with a low CP diet.

Development of a method for the simultaneous determination of ionic nutrients in hydroponic solutions using cation-/anion-exchange chromatography with a neutral eluent.

Nutrient availability in hydroponic solutions must be accurately monitored to maintain crop productivity; however, few cost-effective, accurate, real-time, and long-term monitoring technologies have been developed. In this study, we describe the development and application of cation-/anion-exchange chromatography with a neutral eluent (20-mmol/L sodium formate, pH 7.87) for the simultaneous separation (within 50 min) of ionic nutrients, including K+, NH4+, NO2-, NO3-, and phosphate ion, in a hydroponic fertilizer solution. Using the neutral eluent avoided degradation of the separation column during precipitation of metal ion species, such as hydroxides, with an alkaline eluent and oxidation of NO2- to NO3- with an acidic eluent. The suitability of the current method for monitoring ionic components in a hydroponic fertilizer solution was confirmed. Based on our data, we propose a controlled fertilizer strategy to optimize fertilizer consumption and reduce the chemical load of drained fertilizer solutions.

Hydroponic Nutrient Solution Temperature Impacts Tulane Virus Persistence over Time.

Controlled environment agriculture (CEA), or indoor agriculture, encompasses non-traditional farming methods that occur inside climate-controlled structures (e.g., greenhouses, warehouses, high tunnels) allowing for year-round production of fresh produce such as leaf lettuce. However, recent outbreaks and recalls associated with hydroponically grown lettuce contaminated with human pathogens have raised concerns. Few studies exist on the food safety risks during hydroponic cultivation of leaf lettuce; thus, it is important to identify contributing risk factors and potential mitigation strategies to prevent foodborne transmission via hydroponically grown produce. In this study, the concentration of infectious Tulane virus (TV), a human norovirus surrogate, in hydroponic nutrient solution at 15 °C, 25 °C, 30 °C, and 37 °C was determined over a duration of 21 days to mimic the time from seedling to mature lettuce. The mean log PFU reduction for TV was 0.86, 1.80, 2.87, and ≥ 3.77 log10 at 15 °C, 25 °C, 30 °C, and 37 °C, respectively, at the end of the 21-day period. Similarly, average decimal reduction values (D-values) of TV at 15 °C, 25 °C, 30 °C, and 37 °C were 48.0, 11.3, 8.57, and 7.02 days, respectively. This study aids in the (i) identification of possible food safety risks associated with hydroponic systems specifically related to nutrient solution temperature and (ii) generation of data to perform risk assessments within CEA leaf lettuce operations to inform risk management strategies for the reduction of foodborne outbreaks, fresh produce recalls, and economic losses.

Replacing conventional concentrates with sprouted barley or wheat: Effects on lactational performance, nutrient digestibility, and milk fatty acid profile in dairy cows.

Finite natural resources, rising human population, and climate change pose challenges to traditional crop production. Hydroponically grown fodder (i.e., sprouted grains) can be an alternative feed source for dairy cows; however, only sprouted barley has been investigated in low-producing cows. We aimed to evaluate the effect of replacing conventional concentrates with sprouted barley or wheat, grown using hydroponics, on milk production, nutrient digestibility, and milk fatty acid profile in high-producing cows. Twenty-four multiparous Holstein cows (3.25 ± 1.33 lactations; 102 ± 23 DIM; 49 ± 4 kg/d of milk) were used in a replicated 3 × 3 Latin square design with 21-d experimental periods. Following a 2-wk covariate period, cows were fed 1 of 3 experimental diets: a TMR (1) without sprouted grains (control), or with (2) 10% sprouted barley, or (3) 10% sprouted wheat on a DM basis. Experimental diets were formulated to be isoenergetic and isonitrogenous with sprouted grains that replaced ground corn, soybean meal, canola meal, and dextrose. Sprouted grains were grown using a semi-automatic hydroponic system and harvested after 6 d of growth. Data and sample collection occurred during the last 3 d of the covariate and experimental periods. Wide ranges were observed for the DM percent of sprouted grains (12.1%-22.9% and 13.3%-25.7% for barley and wheat, respectively) and the ratio of sprouted fodder to seed (0.67-1.07 for both barley and wheat). Feeding sprouted grains did not modify the yield of milk or ECM; however, DMI were lower for barley, relative to control. Feed efficiencies were greater for barley than for control (1.49 ± 0.03 vs. 1.43 ± 0.03 for milk yield/DMI; 1.85 ± 0.03 vs. 1.73 ± 0.04 for ECM/DMI). Yields and concentrations of milk components (i.e., fat, true protein, and lactose) were not affected by treatment. Milk urea N concentrations were greater for wheat, relative to control or barley. Body weight (752 ± 3 vs. 742 ± 3 kg) and BW gains (6.53 ± 2.99 vs. -9.33 ± 2.91 kg/21 d) were higher for wheat than for control. Apparent total-tract digestibility of organic matter was greater for wheat relative to barley. Digestibilities of NDF and starch were higher for wheat and control, relative to barley, and CP digestibility was greater for wheat, relative to barley and control. Rumination and physical activity were not affected by treatment. In summary, replacing traditional concentrates with sprouted grains grown using hydroponics improved milk production efficiency (barley sprouts) or enhanced body weight gain (wheat sprouts). A life-cycle assessment needs to be conducted to determine the net effect of this feeding strategy for the dairy industry.