Amino Acid Fertilizer Research Articles

Integrated physiological and transcriptome analyses of the effects of water-soluble amino acid fertilizer on plant growth

Tobacco is a key component of China’s economy, serving as a major cash crop. With traditional fertilizers reaching their maximum potential in promoting tobacco growth, the exploration of new fertilizers has emerged as a viable solution for advancing experimental sustainable development. Spraying foliar fertilizer is a key measure to improve tobacco yield and quality. This study employed a combination of field and pot experiments to investigate the effects of applying water-soluble amino acid fertilizers on the growth, development, and quality of tobacco. The results of transcriptome analysis and physiological index measurements indicate that the application of water-soluble amino acid fertilizer can enhance the area of tobacco leaves, promote photosynthesis, and improve the chemical composition of the leaves. This research determined that the optimal concentration for spraying water-soluble amino acid fertilizer is diluted 500 times. Transcriptome analysis identified a total of 6,489 differentially expressed genes (DEGs), including 3,843 genes that were up-regulated and 2,646 genes that were down-regulated. Gene Ontology (GO)analysis demonstrated that these DEGs were significantlyassociatedwithprocessesincludingcell recognition, photosynthesis,thylakoidcomponents, calcium ion binding, and carbohydrate binding.Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis emphasized that the DEGs were largely found in pathwaysrelated tophotosynthesis-antenna proteins, interactions between plants and pathogens, photosynthesisitself, phenylpropanoid biosynthesis, andplant hormone signaling. Further research revealed that a significant number of genes involved in the auxin, gibberellin, salicylic acid, and jasmonic acid signal transduction pathways exhibited varying expression patterns following the application of water-soluble amino acid fertilizers.Additionally, the expression levels of bZIP, MYB, WRKY, bHLH, and AP2/ERF transcription factors exhibited significant variations following the application of water-soluble amino acid fertilizer. These results analyze the mechanisms of action of water-soluble amino acid fertilizers, offering new effective strategies to enhance both the yield and quality of tobacco.

Quality improvement of tomato (Solanum lycopersicum L.) ‘Optima’ with amino acid-enriched leaf fertilizer

Tomato quality is influenced by fertilization and matutity level. This study aimed to determine the best dosage of amino acid-enriched leaf fertilizer (Amiboost) and to determine the best nutritional content at several ripeness levels of ‘Optima’ tomatoes. Amiboost is an inorganic foliar fertilizer that is rich in amino acids that can be easily absorbed by plants. The experiment used a factorial (RCBD) with 3 repetitions. The ‘Optima’ tomatoes were grown at Wonosobo and fertilized with 4 levels of Amiboost fertilizer consisting of 0, 1, 2, 4 L ha-1 amino acid fertilizer, and 2 L ha-1 comparison fertilizer (standard fertilizer). The research was conducted at the Horticulture Sub-Laboratory, UGM at 27 °C with a relative humidity of 75%. The tomato quality observed was CO2 concentrations, visual quality rating (VQR), fruit weight percentage, fruit hardness, fruit color, total soluble solids, total titrated acid, vitamin C, carotenoids, lycopene, and flavonoids. The observation was terminated when the score of VQR reached 1 as the shelf life of tomatoes. The best dose of amino acid-enriched leaf fertilizer (Amiboost) is 2 L ha-1 for the lightness (*L) of fruit color, ascorbic acid, and lycopene. The maturity stage of fruit significantly affected vitamin C, flavonoids, total soluble solids, carotenoids, and lycopene.
 Keywords: Aminoalkanoic; shelf life; leaf fertilizer; tomato quality

Towards anaerobic digestate valorization to recover fertilizer nutrients: Elaboration of technology and profitability analysis

The study aimed to develop a technology for creating granular fertilizers, containing amino acids, based on food waste digestate. Pork hemoglobin (Ntot: 14.9 ± 1.5%, C: 47.2 ± 4.7%) served as an additional source of nitrogen and organic carbon. The proposed method comprises four unit processes: (1) chemical hydrolysis of raw materials with a mixture of sulfuric (VI) acid and phosphoric (V) acid, (2) neutralization with solid potassium hydroxide and correction of the composition with minerals (sulfate salts of copper, manganese, zinc and iron), (3) granulation with a mixture of biomass combustion, potato starch and peat, and (4) drying the granules. The prepared formulation meets the requirements of European Parliament Regulation 2019/1009 and is classified as PFC 1(B)(I): solid organo-mineral fertilizer (N: 4.49 ± 0.45%, C: 35.0 ± 3.50%, P2O5: 2.83 ± 0.57%, K2O: 4.78 ± 0.96%). The forms of nutrients were determined in accordance with current PN-EN standards. The effect of amino acid fertilizer on cucumber plants (Cucumis sativus, W. Legutko) was studied in 10-day germination tests under normal, salinity and drought conditions. It was noted that a low dose of the preparation under normal conditions had a stimulating effect on root development, while higher supplementation positively affected the aboveground parts of the plants. Under drought conditions, plants accumulated higher amounts of free amino acids, particularly glutamic acid, arginine, glycine, phenylalanine, serine and tryptophan. A significant portion of the study focused on the economic analysis, which included financial calculations for the production of the proposed fertilizer, an evaluation of profitability, and a sensitivity analysis.

Fruit quality and shelf-life improvement of tomato (Solanum lycopersicum L.) 'Servo' by inorganic fertilizer enriched with amino acid

Fertilizer and maturity stage affect the nutritional content and quality of tomatoes. This study aimed to obtain the best dosage of amino acid fertilizer on the qualities and shelf life and to determine the effect of the maturity stage on the qualities of Servo tomatoes. The research design used factorial RCBD with 3 blocks as replications. The Servo tomatoes were grown in Wonosobo District and foliar fertilized with 4 levels of amino acid fertilizer, namely 0, 1, 2, and 4 L ha-1 amino acid fertilizer, and 2 L ha-1 comparison fertilizer. Observation of tomato fruit quality was conducted in Horticulture Sublaboratory, UGM at 27,5 °C with relative humidity of 73%. The quality observed was CO2 concentration, visual quality rating, weight loss, fruit firmness, fruit color, TSS, TTA, carotenoids, lycopene, flavonoids, and vitamin C. The observation was terminated when the score of VQR reached 3 as shelf life of tomatoes. Amino acid fertilizer can improve the quality of Servo tomatoes as seen from the parameters of fruit color (a*) and total titrated acid (TTA). In terms of other parameters, the amino acid fertilizer does not affect the quality of Servo tomatoes. The highest value on fruit color (a*) and TTA resulted from 2 L ha-1 of amino acid fertilizer. The maturity stage significantly affects the quality improvement of fruit firmness, weight loss, VQR, CO2 concentration, TTA, total soluble solids, carotenoids, and flavonoids. L ha-1 
 Keywords: Aminoalkanoic; fertilizer effect; storage life; tomato quality

Alternations in Physiological and Phytochemical Parameters of German Chamomile (Matricaria chamomilla L.) Varieties in Response to Amino Acid Fertilizer and Plasma Activated-Water Treatments

Plasma-activated water (PAW) is an emerging and promising green technology in agriculture in recent years. This study aimed to examine the influence of the spraying of PAW and amino acid fertilizer concentrations on German chamomile varieties’ physiological, biochemical, and phytochemical characteristics under field conditions. Method: The experiment was performed during 2020–2021 as a factorial using a randomized complete block design with three replications in an arid and semi-arid region east of the Persian Gulf. The factors contained five fertilizer levels (0 (control), 1, 2, 3 mL L−1 amino acid and PAW) and three German chamomile cultivars Bona, Bodegold, and Lianka). Physiological, biochemical, and phytochemical traits such as plant height, fresh and dried flower weight, chlorophyll a, b, carotenoids, CHN elements: N ratio, total protein, amino acid profile, essential oil yield, apigenin content, and major secondary metabolites were examined. Results: The ANOVA indicated that the impact of the cultivar and fertilizer was significant on all physiological, biochemical, and phytochemical studied parameters. The amino acid fertilizer and PAW enhanced physiological features, hydrogen, C: N ratio, essential oil yield, apigenin content, and main phytochemical compositions like chamazulene, and α-bisabolol, but it had no incremental effect on the carbon, nitrogen, and total protein percentage. Conclusion: Findings revealed that applying foliar amino acid fertilizer and PAW treatments improves physiological, biochemical, and phytochemical parameters in German chamomile cultivars under field conditions.

Amino acid fertilizer strengthens its effect on crop yield and quality by recruiting beneficial rhizosphere microbes.

There is currently an increase in the use of new types of fertilizers in modern agriculture. Studies have shown that amino acid fertilizers can improve crop yield and quality. However, their effects on crop rhizosphere ecology and their ecological impacts on crop yield are largely unknown. This study evaluated the effects of a water-soluble amino acid fertilizer (WAAF) on tomatoes and its ecological effects on rhizosphere bacterial communities using greenhouse pot experiments. The results showed that WAAF could promote the growth of tomatoes and improve the quality of fruits more effectively than water-soluble chemical fertilizer controls. Interestingly, WAAF showed a different regulating pattern on root exudates and increased the secretion of 17 major water-soluble root exudates, including hexadecanoic acid and 3-hydroxy-γ-butyrolactone. Water-soluble amino acid fertilizer also affected noticeably the composition, abundance, and beta-diversity of rhizosphere bacterial communities, and strengthened the potential relationships between community members. Water-soluble amino acid fertilizer showed a significant selective enrichment ability and recruited some members of the genera such as Cupriavidus, Ralstonia, Chitinophaga, Gemmatimonas, Mitsuaria, Mucilaginibacter, Paracoccus, Sphingopyxis, and Variovorax. Network analysis and functional prediction implied that, besides fertilizer effects, the recruiting of beneficial microbes involved in chemotaxis and biofilm formation was also a considerable factor in tomato yield and quality improvement. Our study revealed ecological and recruiting effects of WAAF on rhizosphere microbes and potentially beneficial microbiota, and provided a basis for the amino acid fertilizer regulation of rhizosphere ecology to improve soil health and further improve crop yield and quality. © 2023 Society of Chemical Industry.

Lysobacter lactosilyticus sp. nov., a Novel β-Galactosidase Producing Bacterial Strain Isolated from Farmland Soil Applied with Amino Acid Fertilizer.

To isolate β-galactosidase producing bacterial resources, a novel Gram-stain-negative, strictly aerobic bacterial strain designated as A6T was obtained from a farmland soil sample. Cells of the strain were rod-shaped (0.4-0.7μm × 1.8-2.2μm) without flagella and motility. Strain A6T grew optimally at 30 °C, pH 7.0 with 0% (w/v) NaCl. Based on phylogenetic analysis, strain A6T clustered within the genus Lysobacter clade and branched with Lysobacter dokdonensis KCTC 12822T (99.5%, 16S rRNA gene sequence similarity) and Lysobacter caseinilyticus KACC 19816T (98.5%). The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain A6T and Lysobacter dokdonensis KCTC 12822T were 82.7% and 26.2%, and the values for strain A6T and KACC 19816T were 81.4% and 23.8%, respectively. Iso-C16:0, iso-C15:0, summed feature 9 (C17:1 iso ω9c and/or C16:0 10-methyl) and summed feature 3 (C16:1ω7c and/or C16:1 ω6c) were the major fatty acids, diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine were the major polar lipids, and ubiquinone 8 (Q-8) was the major ubiquinone. The genomic DNA G+C content was 67.2mol%. Furthermore, under the condition of 30 °C, pH 7.0, 4% inoculation with 10.0gL-1 lactose, the β-galactosidase activity produced by strain A6T was highest, reaching 95.3 UmL-1, indicating that this strain could be applied as a potential strain for β-galactosidase production. Strain A6T represents a novel species of the genus Lysobacter, and Lysobacter lactosilyticus sp. nov. is proposed on the basis of phenotypic, genotypic, and chemotaxonomic analysis. The type strain is A6T (=KCTC 82184T=CGMCC 1.18582T).

Yield and Yield Components of Red Onion (Allium ascalonicum L.) Influenced by Application of Amino Acid Fertilizer and Triacontanol

Red onions are one of the agricultural products with a relatively high demand for the consumer market in Indonesia, but the productivity figure is quite low when compared to other countries (FAO, 2021). This study seeks to explore the effectiveness of the application of amino acid fertilizer and triacontanol in increasing the yield and yield components of red onions. Employing a randomized block design, this study used 2 factors, which are amino acid fertilizers (A1: 1000 ppm; A2: 3000 ppm; A3: 5000 ppm) and triacontanol (T0: 0 ppm; T1: 5ppm; T2: 10 ppm). Each combination is repeated 3 times. As a results, amino acid fertilizers can significantly affect the number of red onions bulbs, yields per hectare, economic weight, and economic weight loss. The interaction of characters of bulb length was shown in the combination of 5-10 ppm triacontanol with amino acid fertilizer. The best response, which ranged from 10.64% to 11.67%, was noted in fertilizer with 5000 ppm of an amino acid fertilizer. As the concentration of amino acid fertilizer in combination with triacontanol increased, the total bulb fresh weight increased as well, in which, 5000 ppm of amino acid fertilizer could increase the weight by 45,23-45,43 g clump-1, which was greater than the response of the 1000 ppm amino acid fertilizer combination.

An amino acid fertilizer improves the emergent accumulator plant Nasturtium officinale R. Br. phytoremediation capability for cadmium-contaminated paddy soils.

Cadmium (Cd) contamination of paddy soil affects safe crop production. This study aimed to evaluate the effects of plant biostimulant amino acid fertilizer on the phytoremediation capability of an emergent accumulator plant Nasturtium officinale R. Br. for Cd-contaminated paddy soils. A pot study was carried out to study the effects of different concentrations of amino acid fertilizer on the Cd accumulation of N. officinale grown in Cd-contaminated paddy soil. The amino acid fertilizer increased the biomass of N. officinale. The amino acid fertilizer concentration exhibited a quadratic polynomial regression relationship with the root and shoot biomass. The fertilizer also increased the photosynthetic pigment (chlorophyll and carotenoid) contents, peroxidase (POD; EC 1.11.1.7) activity, and catalase (CAT; EC 1.11.1.6) activity of N. officinale, but decreased the soluble protein content and had no significant effect on the superoxide dismutase (SOD; EC 1.15.1.1) activity. Furthermore, the amino acid fertilizer increased the Cd content and Cd extraction of N. officinale. The shoot Cd extraction increased by 29.06%, 63.05%, 77.22%, and 17.40% at 1500-, 1200-, 900-, and 600-fold dilutions of the amino acid fertilizer, respectively, compared with the control. Moreover, the amino acid fertilizer promoted the Cd transport from the roots to shoots of N. officinale. The amino acid fertilizer concentration also exhibited a quadratic polynomial regression relationship with the root Cd content, shoot Cd content, root Cd extraction, and shoot Cd extraction, respectively. The correlation, grey relational, and path analyses revealed that the root biomass, shoot biomass, chlorophyll content, catalase activity, shoot Cd content, and root Cd extraction were closely associated with the shoot Cd extraction. Therefore, the amino acid fertilizer can promote Cd uptake and improve the phytoremediation capability of N. officinale to remediate Cd-contaminated paddy soils, and 900-fold dilution is the most suitable concentration.

Effects of Different Bio-fertilizer Treatments on the Growth and Quality of Alfalfa

Background: Alfalfa has small seeds and is intolerant to deep-sowing. We investigated seed emergence of alfalfa variety “Longmu 801” from deep-sowing and its quality improvement through different bio-fertilizer treatments. Methods: Seven fertilization treatments were tested: CK: no fertilization (control), A: amino acid fertilizer, B: amino acid fertilizer + selenium-rich yeast fertilizer diluent, C: amino acid fertilizer + selenium-rich yeast fertilizer dilution + microbial agent, D: amino acid fertilizer + algae extract, E: amino acid fertilizer + microbial agent and F: amino acid fertilizer + selenium-rich yeast fertilizer diluent + microbial agent + algae extract. Result: The bio-fertilizer treatments improved the alfalfa seedling emergence, growth and quality. Treatment E increased the emergence rate, plant height and yield by 10.6%, 41.0% and 68.9%, respectively; decreased the stem-leaf ratio, neutral detergent fiber and acid detergent fiber by 41.7%, 3.7% and 3.17%, respectively and increased crude protein, crude fat and relative feeding value by 2.5%, 0.5% and 8.6%, respectively; compared with that of the control. Soaking alfalfa seeds in 0.2% amino acid fertilizer and applying 13.5 g microbial agent was suggested as the most efficient fertilization technique to promote alfalfa emergence, growth and quality and provide profits to farmers due to its low cost.

Synergistic effect of phytohormone-producing ectomycorrhizal fungus Suillus luteus and fertilizer GGR6 on Pinus massoniana growth

ABSTRACT Suillus luteus is an edible ectomycorrhizal fungus (EMF). The S. luteus strain LS88 secretes many phytohormones, including salicylic acid (SA) and indole-3-carboxylic acid (ICA). LS88 was inoculated to the tree Pinus massoniana and treated with the amino acid fertilizer GGR6. Plant growth parameters, plant enzyme activities, chlorophyll contents, and element contents were analyzed. Our results show that GGR6 may help the development of S. luteus-P. massoniana ectomycorrhiza. Moreover, LS88 and GGR6 synergistically affect P. massoniana growth and element uptake. Phytohormone detection on the roots of LS88-inoculated P. massoniana seedlings showed that LS88 could significantly increase the ICA content within a week. The SA content in the roots in the inoculated group seedlings increased slightly, but the salicylic acid 2-O-β-glucoside (SAG) content decreased. Therefore, we speculate GGR6 may enhance the growth-promoting effect of EMF on plants, and LS88 affects P. massoniana growth through secreting phytohormones.

Yield and Its Components of Shallot (Allium ascalonicum L.) Influenced by the Application of Amino Acid Fertilizer And Triacontanol

Shallot are one of the agricultural products with a relatively high demand for the consumer market in Indonesia, but the productivity figure is relatively low compared to other countries (FAO, 2021). This study seeks to explore the effectiveness of the application of amino acid fertilizer and triacontanol in increasing the yield and yield components of shallot. The study was conducted in Karangploso District, Malang, from April to August 2021. In a randomized block design, this study used two factors: amino acid fertilizers (A1: 1 g plot-1; A2: g plot-1; A3: 5 g plot-1) and triacontanol (T0: 0 ppm; T1: 5ppm; T2: 10 ppm). Each combination was repeated three times. As a result, amino acid fertilizers can significantly affect the number of shallot bulbs, yields per hectare, economic weight, and economical weight loss. A significant effect was seen in the application of triacontanol on shallot yields per hectare and economic weight. The interaction of characters of bulb length was shown in the combination of 5-10 ppm triacontanol with amino acid fertilizer. The best response ranged from 10.64% to 11.67% in fertilizer with 5 g plot-1 of an amino acid fertilizer. As the doses of amino acid fertilizer in combination with triacontanol increased, the total bulb fresh weight grew as well, in which 5 g plot-1 of amino acid fertilizer could increase the weight by 45,23-45,43 g clump-1, which was greater than the response of the 1 g plot-1 amino acid fertilizer combination.

Toxicity evaluation of collagen hydrolysates from chrome shavings and their potential use in the preparation of amino acid fertilizer for crop growth

Resource utilization of chrome shavings (CS) has attracted a lot of attention from scientists and technologists in leather industry. Especially, the collagen hydrolysates extracted from CS are expected to find potential application values in agricultural field. However, there is no biotoxicity analysis of collagen hydrolysates from CS. Herein, the collagen hydrolysates with different molecular weights were produced from CS by three hydrolysis dechroming methods including alkaline hydrolysis, enzymatic hydrolysis and alkaline-enzymatic synergistic hydrolysis, and the optimal hydrolysis process of CS was designed and conducted. To evaluate their toxicity, the three collagen hydrolysates were formulated into a nutrient solution for zebrafish development. The obtained results indicated that the hydrolysates with low concentrations (less than 0.6 mg/mL) were safe and could promote the development for zebrafish embryos. Furthermore, the three collagen hydrolysates were utilized as organic nitrogen sources and formulated into amino acid water-soluble fertilizers (AAWSF) including alkaline type fertilizer (OH), enzymatic type fertilizer (M) and alkaline-enzymatic type fertilizer (OH–M) for the early soilless seeding cultivation of wheat, soybean and rapeseed. It is worth mentioning that the chromium contents in the prepared AAWSF were less than 10 mg/kg, which is far less than the limit value in the standard (China, 50 mg/kg). The growth and development of seedlings (germination rate, plant height, fresh weight of leaves, soluble sugar content and chlorophyll content) were investigated. The corresponding results showed that the growth of seedlings watered with AAWSF was better compared with the other treatments, and the OH–M fertilizer had the best promoting effect on the seedlings growth and development, followed by the M and OH fertilizers. The safe toxicity assessment of the collagen hydrolysates will expand their application scope, and the use of collagen hydrolysates extracted from CS for seedlings growth also provides an effective and reasonable way to deal with the chromium-containing leather solid waste, which is an effective way to realize its resource utilization.Graphical

Foliar N Application on Tea Plant at Its Dormancy Stage Increases the N Concentration of Mature Leaves and Improves the Quality and Yield of Spring Tea.

Over 30% of the Chinese tea plantation is supplied with excess fertilizer, especially nitrogen (N) fertilizer. Whether or not foliar N application on tea plants at the dormancy stage could improve the quality of spring tea and be a complementary strategy to reduce soil fertilization level remains unclear. In this study, the effects of foliar N application on tea plants were investigated by testing the types of fertilizers and their application times, and by applying foliar N under a reduced soil fertilization level using field and 15N-labeling pot experiments. Results showed that the foliar N application of amino acid liquid fertilizer two times at the winter dormancy stage was enough to significantly increase the N concentration of the mature leaves and improved the quality of spring tea. The foliar application of 2% urea or liquid amino acid fertilizer two times at the winter dormancy stage and two times at the spring dormancy stage showed the best performance in tea plants among the other foliar N fertilization methods, as it reduced the soil fertilization levels in tea plantations without decreasing the total N concentration of the mature leaves or deteriorating the quality of spring tea. Therefore, foliar N application on tea plants at its dormancy stage increases the N concentration of the mature leaves, improves the quality and yield of spring tea, and could be a complementary strategy to reduce soil fertilization levels.

Aquamicrobium zhengzhouense sp. nov., a Bacterium Isolated from Farmland Soil Applied with Amino Acid Fertilizer

A novel Gram-stain-negative, rod-shaped, strictly aerobic, non-motile bacterium, designated strain cd-1T, was isolated from a farmland soil applied with amino acid fertilizer in Zhengzhou, Henan province, China. The optimum growth of strain cd-1T occurred at 30°C, pH 7.0 in Luria-Bertani (LB) broth without NaCl supplement. Phylogenetic analysis based on 16S rRNA gene sequences indicated that cd-1T is member of the genus Aquamicrobium, and formed a separate branch with Aquamicrobium aerolatum DSM 21857T (96.5%) and Aquamicrobium soli KCTC 52165T (95.7%). The draft genome sequencing revealed a DNA G + C content of 59.2mol% and Q-10 was the predominant respiratory quinone. The major cellular fatty acids were identified as C18:1 ω7c (35.8%), C19:0 cyclo ω8c (32.1%), and C18:1 ω7c 11-methyl (5.2%). The polar lipids consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylmonomethylethanolamine. Average nucleotide identity (ANI) and the digital DNA-DNA hybridizations (dDDH) for draft genomes between strain cd-1T and KCTC 52165T were 71.0% and 19.9%, respectively, the values for strain cd-1T and DSM 21857T were 73.4% and 20.6%. Based on the physiological and biochemical characteristics, phylogenetic and chemotaxonomic analysis, strain cd-1T is considered to represent a novel species of the genus Aquamicrobium, for which the name Aquamicrobium zhengzhouense sp. nov. is proposed. The type strain is cd-1T (= KCTC 82182T = CCTCC M 2018904T).

Production of free amino acid fertilizer from tung meal by the newly isolated Pseudomonas aeruginosa LYT-4 strain with simultaneous potential biocontrol capacity

Tung meal is the main byproduct generated during tung oil extraction from tung tree (Vernicia fordii) seeds and contains approximately 36–45 wt% crude protein. The disposal of large amounts of this resource has attracted increasing attention in relation to its value-added utilization. In this study, a new strain Pseudomonas aeruginosa LYT-4, was isolated for the bioconversion of tung meal into free amino acid fertilizer. Solid-state fermentation analysis showed that the protease activity of P. aeruginosa LYT-4 treatment was significantly higher than that under natural treatment throughout the fermentation period. The total percentage of free amino acids increased from 46.5% under natural fermentation to 55.5% under P. aeruginosa LYT-4 treatment. Pot experiments revealed that P. aeruginosa LYT-4 fermented-tung meal efficiently promoted spinach growth by increasing biomass and was more effective than both naturally fermented tung meal and chemical fertilizer. Furthermore, P. aeruginosa LYT-4 exhibited efficient in vitro antagonistic activity against three plant pathogens, Colletotrichum lini, Rhizoctonia solani and Fusarium oxysporum, possibly due to the abundant secondary metabolite clusters in its genome based on genomic analysis. In conclusion, P. aeruginosa LYT-4 exhibited a promising prospect for the industrial production of free amino acid fertilizer from tung meal with simultaneous potential biocontrol capacity.

Ammonia and Ammonium Exposure of Basil (Ocimum basilicum L.) Growing in an Organically Fertilized Peat Substrate and Strategies to Mitigate Related Harmful Impacts on Plant Growth.

Organic pot-based production of basil (Ocimum basilicum L.) often has lower biomass yield than conventional cultivation. Previous investigations indicate that this growth impairment is related to high ammonium (NH4 +) concentrations in the growing media released by the mineralization of organic nitrogen (N) fertilizers. However, as a result of this ammonification process substrate pH may also increase. Under neutral to alkaline conditions NH4 + is converted to ammonia (NH3), which is known to be phytotoxic even at low concentrations. Therefore, we investigated the impact of both ammonical N species on basil grown in a peat substrate. In total, three fertilization pot experiments were conducted in a greenhouse in order to compare the effect of different organic base dressings [250 and 750 mg N (L substrate)-1 mainly supplied by a liquid amino acid fertilizer (AAF)] and two initial substrate pH levels (5.5 and 6.5). In two treatments, 5% (v/v) mature compost was mixed into the peat 1 day and 12–days before the substrate was used for sowing, respectively. The aim of this procedure was to stimulate nitrification in this way to reduce ammonical N concentration. Ammonia concentration in the aerial plant surrounding environment was measured by using NH3 detector tubes in combination with an open-top chamber method. The results showed that the growth of basil (number of plants, fresh matter yield, plant height) was significantly inhibited in the second and third week of cultivation by rising NH3 and NH4 + exposure, as well as by a substrate pH ≥ 7.0. These adverse effects were reduced by lowering the organic base dressing rate and adjusting the initial substrate pH to 5.5. Furthermore, the addition of mature compost to peat in combination with a 12-day storage was proven to be effective for promoting nitrification in the organically fertilized substrate. As a result, plant growth was improved by both lower NH3 and NH4 + exposure as well as a faster supply of nitrate (NO3 -) as an additional N source. Using this approach, it was possible to feed organically fertilized basil right from the seedling stage with a NO3 --N/NH4 +-N-balanced and later on providing a predominant NO3 --N supply.

Effects of foliar application of amino acid liquid fertilizers, with or without Bacillus amyloliquefaciens SQR9, on cowpea yield and leaf microbiota.

Leaf surface fertilization with liquid fertilizer produced from amino acids constitutes a potentially important source of nitrogen and is important for plant production. However, few reports have focused on the plant growth promotion by novel liquid fertilizers created by new amino acid resources, let alone the influence on leaf microbiota. In this study, the effects of liquid fertilizer, created by amino acids hydrolyzed from animal hairs with or without the PGPR strain Bacillus amyloliquefaciens SQR9, on crop yield and leaf microbiota were investigated. The results showed that leaves sprayed with amino acid liquid fertilizer (AA) and liquid biological fertilizer (AA9) persistently increased cowpea yields compared to the control amended with chemical fertilizer (CF). Fertilization with amino acid fertilizer showed no significant difference in microbial composition compared with the CF treatment; however, the introduction of functional microbes altered the microbial composition. Pearson correlation analysis, VPA analysis and SEM models all revealed that the amino acids liquid fertilizer application, but not the functional strain or the altered microbiota, performed as the direct driver attributing to yield enhancement. We conclude that leaf fertilization with a novel amino acid liquid fertilizer can greatly enhance the crop yield and that the addition of beneficial microbes may perform the role in further altering the composition of leaf microbiota.

Effect of Oil-Cake and Amino Acid Fertilizer on Soil Bio-Chemical Properties and Pepper Yield

Effect of Oil-Cake and Amino Acid Fertilizer on Soil Bio-Chemical Properties and Pepper Yield

Polyaspartate and liquid amino acid fertilizer are appropriate alternatives for promoting the phytoextraction of cadmium and lead in Solanum nigrum L

Traditional metal chelators, such as ethylenediaminetetraacetic acid (EDTA), have been gradually replaced due to their poor biodegradability in soil and high risk of heavy metal leaching into groundwater, which pose high environmental risks to the health of humans and animals. In this study, a liquid amino acid fertilizer (LAAF, waste proteins from hydrolysates of animal carcasses) and polyaspartate (PASP) were used as additives to enhance the phytoextraction of cadmium (Cd) and lead (Pb) from contaminated soil. We conducted pot experiments to investigate the phytoextraction capacity of Solanum nigrum, a Cd accumulator, grown on soil highly contaminated with Cd and Pb in the absence (as controls) or presence of PASP and LAAF. Both PASP and LAAF significantly improved plant growth, Cd accumulation, and total Cd and Pb content in S. nigrum shoots and roots. PASP and LAAF application promoted Cd translocation from roots to shoots in S. nigrum and Cd bio-accessibility in rhizosphere soils, but this was not the case for Pb. Both PASP and LAAF increased Cd and Pb phytoextraction by S. nigrum plants, and Cd phytoextraction was more effective in LAAF-assisted S. nigrum than in PASP-assisted S. nigrum. These findings demonstrate that the low cost and ecofriendly features of recycled waste proteins make them good candidates for chelant-enhanced phytoextraction from heavy metal-contaminated soils.