Humic Acid Application Research Articles

Comparative Evaluation of Tree Species for Phytoremediation of Heavy Metal-Contaminated Soil: Effects of Humic and Salicylic Acid Application

Comparative Evaluation of Tree Species for Phytoremediation of Heavy Metal-Contaminated Soil: Effects of Humic and Salicylic Acid Application

Effect of Sulfur Granular Municipal Solid Waste, Humic Acid, and Nano Fe-Oxide on Lead Uptake by Plants in a Calcareous Soil in the Presence of Thiobacillus

Soil poisoning with heavy metals is one of the most significant aspects of environmental research. In the soil treated with Thiobacillus, the effect of sulfur granular municipal solid waste (sulfur granular MSW), humic acid, and nano Fe-oxide on reducing Pb absorption by plants was investigated. Treatments consisted of applying sulfur granular MSW (0 and 30 t/ha), spraying humic acid (0 and 1.5 mmol/L), and using nano Fe-oxide (0 and 2% w/w) in the soil contaminated with Pb (0, 600, and 1200 mg/kg-soil). Plants were collected after 5 months, and the Pb content in the soil and plants was estimated by atomic absorption spectroscopy (AAS). The activity of ascorbate peroxidase (APX) and peroxidases (POX) enzymes were also determined. The use of 30 t/ha of sulfur granular MSW in the Pb-polluted soil reduced Pb concentration in the soil and plant by 13.4% and 15.1 %, respectively, while it increased Fe concentration by 15.2% in the plant. Using nano Fe-oxide (2% w/w) in the Pb-contaminated soil (600 and 1200 mg/kg soil) considerably enhanced Fe content in the plant. Pb absorption by plants was dramatically reduced by foliar application of humic acid. According to the findings of this study, the interaction effects of sulfur granular MSW, nano Fe-oxide, and humic acid significantly reduced the Pb absorption by plants. However, the impacts of soil physico-chemical characteristics and the kind of soil pollutant on plant Pb concentration cannot be ignored.

Influence of Foliar Application of Seaweed Extract and Humic Acid on Growth, Yield and Quality of Strawberry (Fragaria × ananasa Duch) cv. Winter Dawn

The present investigation entitled “Influence of foliar spraying of Seaweed extract and Humic acid on growth, yield and quality of Strawberry (Fragaria × ananasa duch) cv. Winter dawn” was carried out in the Department of Horticulture, Sam Higginbottom University of Agriculture Technology & Sciences Prayagraj. This experiment was conducted from November 2022 to March 2023. This experiment was conducted to evaluate the best treatment combination of Seaweed Extract and Humic acid concentration for producing the best quality strawberry. The experiment was laid out in Randomized Design having 9 treatments and replicated 3 times. The T9 (SWE @ 8000ppm + Humic acid @ 3.0 g/L) recorded highest values in terms of growth parameters i.e. number of leaves (7.83, 15.58, 23.66, 30.08), plant height (7.88, 12.21, 15.25, 18.06), plant spread (13.38 E-W, 13.41 N-S; 15.4 E-W, 15.43 N-S; 21.55 E-W, 21.01 N-S; 24.44 E-W, 24.45 N-S) at different stages of growth i.e 30, 60, 90, and 120 days after planting as compared to T1 (control) and all other treatments. Plant treatment T9 also recorded earliest flowering (48.42 days) and earliest fruiting (70.42). Fruit weight (30.84g), fruit length (5.84cm) and diameter (4.05cm) were found superior followed by T8 (SWE @ 7000ppm + Humic acid @ 3.0 g/L). Higher yield (343.52g) and higher number fruits per pant (20.66) were observed in T9 and the lower yield and less number of fruits per plant in T1 (control). In Fruit quality characters, higher TSS (11.13ᴼB), lower acidity (0.58%) and high amount of ascorbic acid (60.16 mg/100 g) was observed in T9 followed by T8. Higher concentrations of seaweed extract and humic acid have been found to have a more significant positive impact on the yield quality of strawberries, demonstrating their superiority in enhancing crop productivity.

Response of endophytic bacteria in sugarcane roots to different slow-release fertilizers with dicyandiamide (DCD) and humic acid (HA) applications

The overuse of chemical fertilizers has severe consequences on environmental ecosystems. However, slow-release fertilizers (SRFs) can reduce the total amount and number of fertilizer applications and improve efficiency. Field experiments were conducted in early March 2016 to investigate the proper usage of SRFs such as dicyandiamide (DCD) and humic acid (HA). Seven treatments were set up as follows: SRF with 120 g t−1 DCD (A); SRF with 150 g t−1 DCD (B); SRF with 235 g t−1 DCD (C); SRF with 3 kg t−1 HA (D); SRF with 8 kg t−1 HA (E); SRF with 18 kg t−1 HA (F); and traditional fertilization (CK). The abundance of endophytic bacteria in sugarcane roots under the B treatment was significantly higher than that under traditional fertilization. At the genus level, Massilia, Granulicella, and Herbaspirillum were unique and dominant in the sugarcane roots under the CK treatment. Compared with CK, Streptomyces was the unique dominant endophytic bacteria in sugarcane roots under different SRFs applications. These results suggest that cane health and tolerance to environmental stresses were not significantly altered after applying SRFs in sugarcane fields.

Effect of humic acid and bread yeast application on the vegetative, yield and qualitative attributes of tomato (Lycopersicon esculentum L.)

Effect of humic acid and bread yeast application on the vegetative, yield and qualitative attributes of tomato (Lycopersicon esculentum L.)

Vegetatife Growth Response Response of Maize Application Of Several Types Of Liquid Organic Fertilizer Bioformulations

One of the causes of low maize yields is soil fertility. The depreciation of soil fertility is partly due to the loss of soil nutrients, which can occur through crop harvesting (nutrient harvesting), run off and leaching. In addition, farmers tend to use chemical fertilizers and pesticides as a means of controlling pests, diseases and weeds. This study was conducted with the aim to see the effect of various bioformulations of Liquid Organic fertilizer enriched with goat urine, T. harzianum and humic acid on better growth and production of corn plants. This research method was arranged in the form of a Completely Randomized Group Design with 5 treatments of LOF bioformulation combination applications made from Goat Urine, Humic Acid and T. harzianum. Those are control (without LOF), goat urine, goat urine and T. harzianum, goat urine and humic acid, and goat urine, T. harzianum and humic acid. The results showed that the application of goat urine, T. harzianum and humic acid gave the highest increase in corn plant height (203.00 cm), the largest number of leaves (11.83 leaves), the largest stem diameter (1.27 cm), the heaviest cob weight (17.67 g). The treatment of LOF enriched with goat urine, T. harzianum and humic acid showed very high results on all parameters measured.

Impact of Sowing Rates and Humic Acid Application on Productivity of Some Triticale Genotypes at East Elquntra

Impact of Sowing Rates and Humic Acid Application on Productivity of Some Triticale Genotypes at East Elquntra

Effect of Foliar Application of Humic Acid and Zinc Sulfate on Vegetative, Physiological, and Biochemical Characteristics of Physalis alkekengi L. Under Soilless Culture

Effect of Foliar Application of Humic Acid and Zinc Sulfate on Vegetative, Physiological, and Biochemical Characteristics of Physalis alkekengi L. Under Soilless Culture

Humic substances extracted from organic compounds and their influence on the morphophysiological characteristics of tomato seedlings

The tomato seedling is one of the main inputs in the production process, and its quality is a strategic factor, making agriculture more competitive. It is possible to produce seedlings of exceptional quality using humic substances extracted from organic compounds, through the composting process. The humic acids present in humic substances play an important role in the release of nutrients, such as N, P, K, improvement of the chemical properties of the soil, elevation of the root system. In this scope, the disposal of organic waste for the composting process can be an economically sustainable alternative. From this, the objective of the research was to test the production of tomato seedlings through the application of humic acids and fulvic acids from the process of composting organic waste. The study was carried out at the State University of Bahia - UNEB, in Euclides da Cunha - BA, using a commercial cultivar. The materials used in the composting process were: coconut fiber, quixabeira soil, cattle manure and humus. Morphophysiological characteristics such as seedling height, stem diameter, chlorophyll content, root length, root volume, fresh and dry mass of tomato roots were evaluated in a completely randomized design with 3 compounds and 5 doses, totaling 15 treatments and 5 repetitions for each compound dose, with a 3x5 factorial scheme. The doses used were 0.0; 0.5; 1.0; 2.0 and 4.0 mL plant-1. Based on the main results, it was possible to conclude that the dose of 0.5 mL plant-1 allowed greater root volume (0.70 cm³), root fresh mass (0.46 g), root dry mass (0.27 g), root length (15.2 cm), seedling height (18.4 cm), stem diameter (0.50 mm), and chlorophyll content (44.5 ug cm-2), in relation to other doses, being, therefore, recommended for root growth of tomato seedlings in semi-arid conditions.

Acclimatisation of orchids using plant growth-promoting bacteria and humic acids

ABSTRACT Acclimatisation of orchid seedlings propagated in vitro is a slow process that can be accelerated with the use of plant growth-promoting microorganisms and humic substances. The aim of this study was to evaluate the plant’s response to inoculation with plant growth-promoting bacteria and humic acids, as well as to their combined use, during the period of acclimatisation of Cymbidium sp. orchids. The treatments were control; application of humic acids; inoculation with Stenotrophomonas maltophilia; inoculation with Burkholderia cepacia; inoculation with S. maltophilia and B. cepacia; inoculation with S. maltophilia combined with application of humic acids; inoculation with B. cepacia combined with application of humic acids; inoculation with S. maltophilia and B. cepacia combined with application of humic acids. A total of 150 days after acclimatisation, the plants were biometrically and nutritionally evaluated. Inoculation with the bacterial strains separately promoted seedlings with greater N content; however, only inoculation with S. maltophilia, resulted in plants with more total dry matter in relation to the control. There was no response from application of humic acids in an isolated manner or in combination with the bacterial strains. The results indicate the biotechnological potential of the bacteria S. maltophilia in promoting the growth of the Cymbidium sp. orchid.

Effects of Mineral Fertilization and Organic Amendments on Rice Grain Yield, Soil Quality and Economic Benefit in Newly Cultivated Land: A Study Case from Southeast China

Low soil fertility and low microbiological activity have been widely observed in certain newly cultivated lands. To develop effective agricultural management practices that can improve soil quality rapidly, a field experiment was conducted on paddy fields reclaimed from unused, low-slope, hilly wasteland in Quzhou City, Zhejiang Province, Southeast China. The six treatments that were applied included (1) control (CK), no crops were planted and no fertilizers were applied; (2) R, rice planted without fertilization; (3) RR, rice–ryegrass rotation without fertilizer application; (4) RRM, rice–ryegrass rotation with the application of mineral fertilizer; (5) RRMO, rice–ryegrass rotation with the application of mineral fertilizer and organic manure; and (6) RRMH, rice–ryegrass rotation with mineral fertilizer and humic acid application. The results showed that the application of fertilizer with ryegrass cropping improved the amounts of soil organic C (SOC) by 115–296% and particulate organic C (POC) by 162–256% (p < 0.05). Additionally, the RRMO treatment had the highest soil quality index value (0.81), which was significantly higher (p < 0.05) than that of the other treatments. The random forest model showed that N-related properties (including urease activity, total N, and particulate organic N), C-related properties (including SOC, POC, and cellulase activity), and available P could significantly (p < 0.05) explain the response of rice yield to different fertilization management strategies. Compared with CK, the cultivated land quality grades of RRMO and RRMH increased from Grade 9 to Grade 7. However, the RRMH obtained the highest net profit from farmland quota trading. Overall, RRMO and RRMH are suggested to rapidly improve soil productivity and maximize the economic benefit of newly cultivated land utilization, respectively.

Humic Acid Modulates Ionic Homeostasis, Osmolytes Content, and Antioxidant Defense to Improve Salt Tolerance in Rice.

The sensitivity of rice plants to salinity is a major challenge for rice growth and productivity in the salt-affected lands. Priming rice seeds in biostimulants with stress-alleviating potential is an effective strategy to improve salinity tolerance in rice. However, the mechanisms of action of these compounds are not fully understood. Herein, the impact of priming rice seeds (cv. Giza 179) with 100 mg/L of humic acid on growth and its underlaying physiological processes under increased magnitudes of salinity (EC = 0.55, 3.40, 6.77, 8.00 mS/cm) during the critical reproductive stage was investigated. Our results indicated that salinity significantly reduced Giza 179 growth indices, which were associated with the accumulation of toxic levels of Na+ in shoots and roots, a reduction in the K+ and K+/Na+ ratio in shoots and roots, induced buildup of malondialdehyde, electrolyte leakage, and an accumulation of total soluble sugars, sucrose, proline, and enzymic and non-enzymic antioxidants. Humic acid application significantly increased growth of the Giza 179 plants under non-saline conditions. It also substantially enhanced growth of the salinity-stressed Giza 179 plants even at 8.00 mS/cm. Such humic acid ameliorating effects were associated with maintaining ionic homeostasis, appropriate osmolytes content, and an efficient antioxidant defense system. Our results highlight the potential role of humic acid in enhancing salt tolerance in Giza 179.

Artificial humic acid promotes growth of maize seedling under alkali conditions

Salinization of cropland is one of the major abiotic stresses affecting global agricultural sustainability, posing a serious threat to agricultural productivity and food security. Application of artificial humic acid (A-HA) as plant biostimulants has been increasingly attracting farmers and researchers. However, its regulation of seed germination and growth under alkali stress has rarely received attention. The purpose of this study was to investigate the response of maize (Zea mays L.) seed germination and seedling growth after the addition of A-HA. The effects of A-HA on seed germination, seedling growth, chlorophyll contents and osmoregulation substance under black and saline soil conditions were studied by soaking maize in solutions with and without various concentrations of A-HA. Artificial humic acid treatments significantly increased the seed germination index and dry weight of seedlings. The effects of maize root in absence and presence of A-HA under alkali stress were also evaluated using transcriptome sequencing. GO and KEGG analyzes were performed on differentially expressed genes, and the reliability of transcriptome data was verified by qPCR analysis. Results showed that A-HA significantly activated phenylpropanoid biosynthesis, oxidative phosphorylation pathways and plant hormone signal transduction. Moreover, Transcription factor analysis revealed that A-HA induced the expression of several transcription factors under alkali stress which had a regulatory effect on the alleviation of alkali damage in the root system. Overall, our results suggested that soaking seeds with A-HA can alleviate alkali accumulation and toxicity in maize, constituting a simple and effective strategy to mitigate saline toxicity. These results will provide new insights for the application of A-HA in management to reduce alkali-caused crop loss.

Response of Sugar Beet Growth to Soil Application of Humic Acid and Foliar Application of Some Biostimulators under Saline Soil Conditions

Response of Sugar Beet Growth to Soil Application of Humic Acid and Foliar Application of Some Biostimulators under Saline Soil Conditions

Effect of Foliar Application of Humic Acid and Nano-NPK on Some Growth Characteristic of Apple Trees Malus Domestica Borkh

This study was carried out in one of the private orchards, which are 20 km away from Kirkuk province in the Altun Kobri area, during the period from May 2021 to August 2021, to study the effect of fertilizing with humic acid at three levels (0, 20, 40) gm and spraying with fertilizer The nano NPK with four levels (0, 1.5, 2.5, 3.5) g.L-1 in some growth characteristics and the yield of apple trees of the local Ibrahimi variety. The experiment was designed according to the design of randomized complete blocks (RCBD), a factorial investigation that included three factors of humic acid and four factors of the compound fertilizer nano NPK and with three replications, the number of treatments in each sector (12) treatments, and with 36 trees included in this experiment, and the treatments were distributed randomly on the experimental units, and for analyzing the data we use the SAS program, and the Duncan polynomial test was adopted under the probability level of 5%. The results showed that the humic acid fertilization gave significant differences in the averages of the studied traits, as the treatment of humic fertilizer at the level (40) gave the highest rate in the following characteristics (the chlorophyll content of the leaves and the proportion of potassium and phosphorous in the leaves). In contrast, the treatment (20) gave the highest rate in Characteristics (the percentage of nitrogen in leaves and leaf area). As for the treatment of spraying with nanocomposite fertilizer with a concentration of (3500), it achieved the highest rate in the characteristics (the content of chlorophyll in the leaves and the percentage of nitrogen, phosphorous and potassium in the leaves), while it gave the concentration (2500) the highest rate in the leaf area. The results also showed that the binary interaction achieved significant differences in the studied traits, as treatment (40) of humic fertilizer and (3500) of the nano-complex fertilizer achieved the highest rate in most of the studied features, namely (leaf area, leaf content of chlorophyll and phosphorous percentage in leaves).

Effect of Humic Acid Applications on Physiological and Biochemical Properties of Soybean (Glycine max L.) Grown under Salt Stress Conditions

In the study, humic acid was applied to soybean (Glycine max L.), which has high economic value and importance, to determine the tolerance level of the plant against salt stress, and physical and chemical changes in the plant were observed. The study was carried out in the climate room of Van Yuzuncu Yil University Faculty of Agriculture, Department of Field Crops in 2019. In the research, İlksoy soybean variety was used. The experiment was carried out in 4 factorial orders according to the factorial experiment was designed based on Completely Randomized Design. In the research, four different Humic acid doses (0, 500, 1000 and 2000 ppm) and 3 different NaCl salt doses (0, 125 and 250 mM) were used. In the study, root length, stem length, root fresh weight, stem fresh weight, root dry weight, stem dry weight, leaf area, chlorophyll content, ion leakage in leaf tissues, lipid peroxidation level (MDA), relative water content and membrane resistance index in leaf tissues were determined. Properties such as index were also examined. As a result of the study, the longest root was 38 cm for the control plots that salt and humic acid didn’t apply to the plants. The highest root fresh weight was 2.08 g and the stem fresh weight was 1.87 g of the plots where 500 ppm humic acid dose applied. In addition, the plants with the highest chlorophyll ratio was 51.05 under 250 mM salt applied without humic acid application.

Morphological Growth of Soybean (Glycine max L.) Treated with Soil Application of Humic Acid under Different Cultivation Periods

The demand of organic cultivation of plants is increasing and soil application of organic fertilizer reduces the hazardous usage of inorganic fertilizer and Humic acid is an organic compound derived from plant and animal residues and microbial cells with long-term physical, chemical, and biological processes. In addition, ultivation of soybean in Kurdistan region is not in a wide value therefore, the objective of this study was to determine the impact of soil application of different rates of Humic acid as an organic fertilizer on the growth characteristic of soybean cultivated and determining the best cultivation period for soybean growth. The experiment was conducted in randomized complete block design with two factor treatments and 3 replication, the first factor was one dose soil application of four different Humic Acid rates (HAR) which were (0 (control), 2,4,6,8 g/L) and two cultivation period (CP) which were cultivation Period 1 (CP1) on 15 May 2022 and cultivation Period 2 (CP2) on 1st of June 2022. Observations were made against the growth parameters of plant height number of branches, leaf area, root length, shoot fresh weight and shoot dry weight. The effect of soil application of humic acid rates (HAR) was highly significant on the plant height and root length and significant on the No. of branches, shoot fresh and dry weight. While, cultivation period insignificantly affected the growth parameter except for leaf area. was significant. The maximum plant height, number of branches, leaf area, root length, shoot fresh and dry weight were observed with soil application of 8 g/L of humic acid which were (82.83 (cm), 23.33, 8815 (mm2), 68.83 (cm), 503.33 (g) and 190.00 (g) respectively. The highest plant height (72 cm), number of branches (18.87), leaf area (7714 mm2), root length (57.13 g), shoot fresh (263.67 g) and dry weight (102.93 g) were observed when the planted cultivated in 1st period (CP1) compared to CP2.

Effect of proline and humic acid application in salinity stress mitigation on some vegetables in hydroponics

The research aimed to find suitable solutions to reduce the salinity stress of irrigation water for some types of vegetables in hydroponics under two drip and mist irrigation systems. The different concentrations of NaCl for irrigation water, are 500, 1000, 2000, 3000, and 4000 ppm used. Proline (30 mg∙dm –3), humic acid (300 mg∙dm –3) and compared without any from them were used to study their effect on the yield, and water use efficiency. The results indicated that the highest spinach and courgette yield (4.657 and 5.153 kg∙m –2) was observed for the DP500 treatment, and the lowest yield (0.348 and 0.634 kg∙m –2) was observed for the SW4000 treatment, respectively. The use of humic acid led to an increased yield on average by about 16.8 and 19.3% for spinach, and 39.4 and 51.7% for courgette, under drip and mist irrigation, respectively. Using proline led to an increased average yield of about 32.9 and 33% for spinach, and 51.8 and 58.4% for courgette, under drip and mist irrigation, respectively. The highest water use efficiency (WUE) of spinach and courgette (43.1 and 51.5 kg∙m –3) was observed for the DP500 treatment, and the lowest (3.2 and 6.3 kg∙m –3) was observed for the SW4000 treatment. According to our study, the use of proline and humic acid could compensate for the adverse effects of salinity under mist spraying more than drip irrigation.

Water deficit stress impairment of morphophysiological and phytochemical traits of Stevia (Stevia rebaudiana Bertoni) buffered by humic acid application

Water deficit stress impairment of morphophysiological and phytochemical traits of Stevia (Stevia rebaudiana Bertoni) buffered by humic acid application

The biological and biochemical composition of wheat (Triticum aestivum) as affected by the bio and organic fertilizers

Microorganisms and organic compounds (humic and fulvic acid) offer viable alternatives to insecticides and mineral fertilizers. Even though many studies have shown the effects of biofertilizers and organic substances separately, little information is available on plant responses to the combined application of these bio-stimulants, even though these biological inputs have a high potential for simultaneous action. A two-year (2020/21–2021/22) field experiment was conducted to investigate the impact of organic and biofertilizers application on the growth, yield, and biochemical attributes of wheat (cv. Misr-1). Pre-planting, wheat seeds were inoculated with two biofertilizers including Mycorrhizae, and Azotobacter, and their combination (MIX), and control (un-inoculation) were considered the main plot factor. The subplot factor contained the foliar sprays of humic acid, fulvic acid, and control (no spray). The results revealed that the seed inoculation with mycorrhizae and azotobacter in combination with foliar-applied humic acid markedly (p ≤ 0.05) affected the growth, yield, and seed biochemical composition of wheat. Combination of mycorrhiza and azotobacter significantly (p ≤ 0.05) increased) plant height (100 cm), crop growth rate (18.69 g), number of spikelets per spike (22), biological yield (13.4 ton ha-1), grain yield (5.56 ton ha-1), straw yield (8.21 ton ha-1),), nitrogen (2.07%), phosphorous (0.91%), potassium (1.64%), protein content (12.76%), starch (51.81%), and gluten content (30.90%) compared to control. Among organic fertilizers, humic acid caused the maximum increase in plant height (93 cm), crop growth rate ( 15 g day-1 m-2),1000 grain weight (51 g), biological yield ( 11ton ha-1), grain yield (4.5 ton ha-1), protein content (11%), chlorophyll content (46 SPAD), and gluten (29.45%) as compared to all other treatments. The foliar application of humic acid combined with the mycorrhizae or azotobacter seed inoculation was efficient to induce wheat vegetative growth development, as well as yield and its components.