Humic Acid Application Research Articles

AGRONOMIC EFFICIENCY OF HUMIC AND FULVIC ACIDS, FUNGI, BACTERIA, USED IN THE CULTURE OF THE SECOND SAFRA

The implementation of the research took place in the period corresponding to the second harvest of the 2022/2023 agricultural year, by the company Pesquisa e Consultoria Agronômica, in geographic coordinates located at 28°18'18'' south latitude, 38°15' 21'' longitude west. The research aimed to evaluate, through the application of biological products, whether it would be possible to obtain more vigorous and productive plants, in order to quantify their agronomic efficiency, thus validating the use of new technological alternatives in nutritional management in corn cultivation. The P3707 hybrid was used and the composition of the treatments is T1: Control treatment with Azospirillum brasilense bacteria (AbV5) (0.100 L ha-1) (planting juice); T2: Azospirillum brasilense (AbV5) (0.100 L ha-1) + Trichoderma asperellum BV10 (0.100 L ha-1) + Bacillus amyloliquefaciens (0.200 L ha-1) (planting juice); T3: Azospirillum baldaniorum, Bacillus amyloliquefaciens; Bacillus proteolyticus and Pseudomonas aeruginosa (0.200 kg ha-1) (planting juice); T4: Azospirillum brasilense (AbV5) (0.100 L ha-1) + Humic and fulvic acids, Azospirillum baldaniorum, Bacillus amyloliquefaciens; Bacillus proteolyticus and Pseudomonas aeruginosa (0.200 kg ha-1) (TS); T5: Humic and fulvic acids, Azospirillum brasilense (AbV5) (0.400 L ha-1) + Azospirillum baldaniorum, Bacillus amyloliquefaciens; Bacillus proteolyticus and Pseudomonas aeruginosa (0.400 kg ha-1) (planting juice); T6: Humic and fulvic acids, Azospirillum brasilense (AbV5) (0.100 L ha-1) + Azospirillum baldaniorum, Bacillus amyloliquefaciens; Bacillus proteolyticus and Pseudomonas aeruginosa (0.400 kg ha-1) (TS). The technological variables evaluated include plant population at the phenological stage (R5), plant height (V3 and R1), root diameter (V3 and R1), insertion height of the first ear, number of ears per plant, root volume (V3 and R1 ), fresh mass of roots (V3 and R1), dry mass of roots (V3 and R1), thousand grain weight, kilogram productivity per hectare. The data obtained were subjected to analysis of variance and the means of the treatments compared using the Tukey method of separation of means, using R Core Team (2019) with a significance of 5%. The application of humic acid, fulvic acid, fungi, bacteria in seed treatment provided gains in fresh aerial part mass, grain weight and greater productivity of the corn crop.

Influence of row density and foliar humic acid application on growth parameters, yield and yield components of Niger (Guizotia abyssinica Cass.) in Erbil

Influence of row density and foliar humic acid application on growth parameters, yield and yield components of Niger (Guizotia abyssinica Cass.) in Erbil

Speciation, phytoavailability, and accumulation of toxic elements and sulfur by humic acid-fertilized lemongrass and common sage in a sandy soil treated with heavy oil fly ash: A trial for management of power stations wastes

Globally, power stations generate huge amounts of the hazardous waste heavy oil fly ash (HOFA), which is rich in Ni, V, Fe, S, and dumped into landfills. Thus, exploring new approaches for a safe recycling and sustainable management of HOFA is needed and of great environmental interest. The potential application of HOFA as an amendment to sandy soils has not been studied yet. This is the first research investigating the potentiality of using HOFA as a soil conditioner. To this end, we conducted a greenhouse experiment in order to investigate the impacts of HOFA addition (1.2, 2.4, 3.6 t ha−1) to sandy soil on the total and available content of nutrients (e.g., S, Fe, Mn, Cu, Zn) and toxic elements (TEs; e.g., Cd, Co, Cr, Ni, Pb, V) in the soil and their phytoextraction and translocation by lemongrass (Cymbopogon citratus) and common sage (Salvia officinalis). We also assessed the impact of humic acid (HA) foliar application (50 and 100 l ha−1) on the growth and elements accumulation by the two plants. The studied HOFA was acidic and highly enriched in S (43,268.0), V (3,527.0), Ni (1774.0), and Fe (15,159.0) (units in mg kg−1). The X-ray absorption near edge structure (XANES) data showed that V in HOFA was composed primarily of V(IV) sorbed onto goethite, V(V) sorbed onto humic substances, in the forms of V2O3, and VCl4. Addition of the lower doses of HOFA (1.2 and 2.4 t ha−1) did not change significantly soil pH, salinity, and the total and available elements content compared to the unamended soil. Although the elements content in the 3.6 t ha−1 HOFA-treated soil was significantly higher than the untreated, the total content of all elements (except for Ni) was lower than the maximum allowable concentrations in soils. HOFA addition, particularly in the highest dose (3.6 t ha−1), decreased significantly the growth and biomass of both plants. Common sage accumulated more elements than lemongrass; however, the elements content in the plants was lower than the critical concentrations for sensitive plants. The foliar application of humic acid enhanced significantly the plant growth and increased their tolerance to the HOFA-induced stress. We conclude that the addition of HOFA up to 2.4 t ha−1 in a single application as amendment to sandy soils is not likely to create any TE toxicity problems to plants, particularly if combined with a foliar application of humic acid; however, repeated additions of HOFA may induce toxicity. These findings should be verified under field conditions.

Effects of Environmentally Friendly Materials on Saline Soil Improvement and Sunflower Yields in the Hetao Irrigation Region, China

The Hetao irrigation region is located in Inner Mongolia, China, within a dry and semi-dry region. This region suffers from poor agricultural productivity and environmental damage due to the presence of saline soil. To explore the growth of salty lands using a more environmentally friendly method, this research employed three eco-conscious amendments to improve the soil. These include flue gas desulfurization gypsum (S), humic acid (H), and biochar (C). During a two-year study, the amendments were utilized to enhance the soil quality for planting sunflowers. Humic acid was used prior to every seedling season, whereas the remaining two substances were only used once. These additions increased the soil’s water-holding capacity, reduced soil salinity during sunflower growth, and improved the macroaggregate proportion. The most effective treatment for decreasing the soil’s salt content after the seedling stage was the application of humic acid (0.6 t ha−1). Biochar (15 t ha−1) decreased the soil’s bulk density (from 1.49 to 1.34 g cm−3) and mostly increased the sunflower seed yield up to 3133−3964 kg ha−1. Humic acid addition significantly increased the aggregate (>0.25 mm) content up to 27.88% after the experiment, but it led to a lower seed yield (2607−3686 kg ha−1). In 2019, the temperature was lower compared to 2018, which may have led to a reduction in the yield. However, these three amendments could potentially increase yields by more than conventional methods. These three environmentally friendly amendments are useful for improving saline soil and increasing yields. More studies are required to understand their impacts on larger areas and over extended periods.

Assessment of Foliar Application of Biostimulants and Silicon on Yield and Yield Attributing Characters of Mango (Mangifera indica l.) CV. Kesar

The present investigation was carried out at Fruit Research Station, Sakkarbaug, Junagadh Agricultural University, Junagadh during 2020-21 and 2021-22. The experiment was laid out in Randomized Block Design with Factorial concept consisting two factors with three replications. The treatment comprised with biostimulants viz., without biostimulant, humic acid (1.5 %), panchagavya (3 %), seaweed extract (0.2 %), novel organic liquid fertilizer (2 %) and silicon i.e., without silicon, potassium silicate (0.2 %) and orthosilicic acid (0.2 %). The results of the study indicated that among the different biostimulants application of humic acid 1.5 % and among the different silicon application of potassium silicate 0.2 % was recorded with minimum number of nubbins per 100 fruits at pea (20.42 and 22.52) and marble stage (10.67 and 12.80) and maximum fruits retention at harvesting (2.03 and 1.85 %), number of fruits per tree (213.71 and 195.52), fruit yield (50.78 and 45.14 kg/tree), fruit length (10.60 and 10.39 cm), fruit breadth (6.67 and 6.55 cm), fruit weight (234.58 and 226.24 g), pulp weight (175.87 and 168.79 g) and pulp: stone ratio (5.16 and 5.07) during pooled analysis, respectively. In the present investigation some of the interaction effects were also found significant. The combined application of humic acid 1.5 % with potassium silicate 0.2 % recorded maximum number of fruits per tree (235.57), fruit yield (60.42 kg/tree), fruit length (11.06 cm), fruit breadth (96.86 cm), fruit weight (254.71 g) and pulp weight (192.61 g) during pooled analysis. It can be concluded that for improved yield and yield attributing characters with foliar application of humic acid 1.5 % along with potassium silicate 0.2 % at initiation of flowering, pea and marble stage.

Trace Elements in Maize Biomass Used to Phyto-Stabilise Iron-Contaminated Soils for Energy Production

The aim of the study was to determine the feasibility of using maize biomass for the phyto-stabilisation of iron-contaminated soils under conditions involving the application of humic acids (HAs). The biomass yield content of maize trace elements was analysed. In the absence of HAs, the first dose of Fe-stimulated plant biomass growth was compared to the absence of Fe contamination. The highest soil Fe contamination resulted in a very large reduction in maize biomass yield, with a maximum of 93%. The addition of HAs had a positive effect on plant biomass, with a maximum of 53%, and reduced the negative effect of Fe. There was an almost linear increase in maize biomass yield with increasing doses of HAs. Analogous changes were observed in dry matter content in maize. Soil treatment with Fe caused a significant increase in its content in maize biomass, with a maximum increase of three times in the series without HAs. There was also a decrease in Co, Cr and Cd content (by 17%, 21% and 44%, respectively) and an increase in Cu, Ni, Pb, Zn and Mn accumulation (by 32%, 63%, 75%, 97% and 203%, respectively). The application of HAs to the soil reduced the content of this trace element and its growth in the biomass of this plant under the influence of Fe contamination. They had a similar effect on other trace elements contained in the maize biomass. HAs contributed to a decrease in the level of most of the tested trace elements (except Ni and Pb) in the maize biomass. The reduction ranged from 11% (Cr and Mn) to 72% (Cd). The accumulation of Ni and Pb in the maize biomass was higher in the objects with HAs application than in the series without their addition. Humic acid application is a promising method for the reduction of the effects of soil Fe contamination on plants.

Application of humic acid in a water recirculating system: influences on total ammonia nitrogen (TAN) removal efficiency of biofilter and growth performance of Nile tilapia (Oreochromis niloticus)

Application of humic acid in a water recirculating system: influences on total ammonia nitrogen (TAN) removal efficiency of biofilter and growth performance of Nile tilapia (Oreochromis niloticus)

Transcriptome analysis reveals the humic acids and chitosan suppressing Alternaria solani growth.

Understanding the inhibitory effects of natural organic substances on soil-borne pathogenic fungi and the relevant molecular mechanisms are highly important for future development of green prevention and control technology against soil-borne diseases. Our study elucidates the inhibitory effect of the combined application of humic acids (HAs) and chitosan on Alternariasolani and the light on the corresponding mechanism. The effect on A. solani growth by HAs incorporated with chitosan was investigated by plate culture and the corresponding mechanism was revealed using transcriptomics. The colony growth of A. solani was suppressed with the highest inhibition rate 33.33% when swine manure HAs was compounded with chitosan at a ratio of 1:4. Chitosan changed the colony morphology from round to irregularly. RNA-seq in the HAs and chitosan (HC) treatment revealed 239 differentially expressed genes compared with the control. The unigenes associated with enzymes activities related to growth and biological processes closely related to mycelial growth and metabolism were downregulated. RNA-seq also revealed that chitosan altered the expression of genes related to secondary metabolism, fungal cell wall formation and polysaccharide synthesis, and metabolism. Meanwhile, weighted gene co-expression network analysis showed that, genes expression in the module positively correlated with mycelial growth was significantly reduced in the HC treatment; and the results were verified by real-time quantitative polymerase chain reaction. The co-inhibition effect of HAs and chitosan on A. solani is associated with downregulated genes expression correlated with mycelial growth.

Does humic acid foliar application affect growth and nutrient status of water-stressed maize?

Maize (Zea mays L.) is one of the world's most important crops, but its productivity is at high risk as climate change increases the risk of water stress. Therefore, the development of mitigation strategies to combat water stress in agriculture is fundamental to ensure food security. Humic acids are known to have a positive effect on drought tolerance, but data on their efficacy under waterlogging are lacking. This study aimed to elucidate the effect of a new humic acid product, a by-product of Ukrainian bentonite mining, on maize growth and nutrient status under waterlogging. Maize was grown for 9 weeks and three water stress treatments, which were applied for 14 days: waterlogging, alternating waterlogging and drought, and drought. On the day of stress application, the humic acid product (1% v/v) was applied to the leaves. Soil Plant Analysis Development (SPAD) values were recorded during the stress treatments. Plants were harvested after stressing ceased and fresh weight and P and Zn status were analyzed. Drought reduced shoot fresh weight, while it was unaffected under waterlogging. This is in contrast to SPAD readings, which showed a significant decrease over time under submergence, but not under drought. Under alternating stress, although SPAD values declined under waterlogging but stabilized when switched to drought, no growth reduction was apparent. Application of the humic acid product was ineffective in all cases. Although anthocyanin discoloration occurred under waterlogging stress, P deficiency, which is usually the main factor driving anthocyanin formation, was not the reason. Interestingly, Zn concentration decreased under waterlogging but not under the other stresses, which was alleviated by humic acid application. However, no effect of foliar-applied humic acids was observed under alternating and drought stress. It can be concluded that the tested humic acid product has the potential to improve the Zn status of maize under waterlogging.

Improving Quantitative and Qualitative Traits of Grapes cv. ‘Fakhri’ of Iran with Foliar Application of Potassium Silicate and Humic Acid

Improving Quantitative and Qualitative Traits of Grapes cv. ‘Fakhri’ of Iran with Foliar Application of Potassium Silicate and Humic Acid

Bioactivation of Legacy Phosphorus in Calcareous Soil by P-Activators and Its Effect on Maize Growth

ABSTRACT Soil legacy phosphorus (P) accumulated due to the long-term continuous application of P fertilizers in agricultural fields accumulated in the soil for years, as sparingly soluble forms. This can be made as a possible soil P source using P-activators. In this study, a laboratory incubation and a pot experiment were conducted to evaluate the potential of some P activators (Phosphorus solubilizing bacteria, phytase, humic acid, oxalic acid) in increasing the availability of residual phosphorus in calcareous soil. For the incubation experiment, the P activators were applied alone and in combination. Soil samples were analyzed at subsequent intervals for soil available P, alkaline phosphatase activity, and sequential P fractions. The results showed that phytase application with humic acid (HA) increased the available soil P (12.4 kg ha−1) and alkaline phosphatase activity (47.42 µg p-nitrophenol released g−1 soil hr−1) followed by phosphorus solubilizing Bacteria (PSB) with humic acid and PSB with phytase treatments. All treatments have a significant effect on different soil P-fractions. A greater reduction in calcium phosphate fraction was noted in phytase and humic acid application. The combined application of P-activators performed better than their sole application. The best three treatments selected from the laboratory incubated experiment were used for the pot experiment with maize, along with the different dosages of P fertilizer. The morphological parameters were observed on the 30th and 60th days of the maize crop. The results of plant height, chlorophyll index, and dry matter production showed that the application of phytase and HA with 100% recommended dose of P was statistically comparable with phytase and HA with 75% recommended dose of P. The findings have illustrated the extent of P release by different P activators in increasing the legacy P availability. The application of phytase and HA with 25% reduced dose of P fertilizers will promote the availability of legacy P in calcareous soils through solubilization.

Effect of CaCO3, humic acid, and arbuscular mycorrhizal applications on soybean growth in ultisol of Sijunjung, West Sumatra

Soybean is an important source of cheap protein. However, an adequate supply of soybeans is still challenging in Indonesia. This research aimed to evaluate the morphological, physiological, and yield responses of soybeans from the application of calcium carbonate (CaCO3), humic acid, and arbuscular mycorrhizal fungi (AMF). The research was conducted from December 2022 to April 2023 at the ultisol soil of Sijunjung Regency, West Sumatra. The experiment used a split-split-plot design with three replications. The first factor was AMF and without AMF application. The second factor was humic acid and without humic acid. The third factor was doses of CaCO3 application: 0, ¼, ½, ¾, and 1 time of exchangeable Al. The results showed that CaCO3 application significantly affected root length, shoot dry weight, N-tissue content, soil pH, and exchangeable Al. The application of AMF affected the percentage of AMF colonization. The yield components did not show any significant differences among treatments. However, the yield was 24.85% higher than that written in the official description. Therefore, the application of CaCO3 or humic acid or AMF could be a potential solution to increase soybean yields in ultisol. It needs further evaluation in the field to support future farming practices. Keywords: Al-exch; calcium carbonate; N-tissue content; productivity; soil pH

Influence of Zinc and Humic Acid Application on Growth Parameter, Yield and Yield Components and Quality Traits of Black Gram (Vigna mungo L.)

A field experiment was conducted in kharif season during 2021-22 on the field at village Ap-Sonalagi Tq-Jath Dist- Sangli of Maharashtra through Department of Soil Science and Agricultural Chemistry College of Agriculture, Badnapur, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, with objectives, to study the influence of zinc and humic acid application on growth parameter, yield and yield components and quality traits of black gram (Vigna mungo L.) The field trial was conducted in Randomized Block Design with five treatments (T1): RDF (25:50:00 N, P2O5, K2O kg ha-1), (T2): RDF+ ZnSO4 @ 25 kg ha-¹, (T3): RDF+ ZnSO4 @ 25 kg ha-¹ + Humic Acid @ 5 kg ha-¹, (T4): RDF+ ZnSO4 @ 25 kg ha-¹ + Humic Acid @ 10 kg ha-¹, (T5) RDF+ ZnSO4 @ 25 kg ha-¹ + Humic Acid @ 15 kg ha-¹ with four replications.According to the results obtained by the field investigation clearly indicated that the significantly higher plant height (44.50 cm), maximum number of branches plant-1 (9.10), number of pods plant-1 (26.15) and grain and straw yield (1305.00 and 2190.00 kg ha-1) at harvest stage were observed in treatment (T5) RDF+ ZnSO4 @ 25 kg ha-¹ + Humic Acid @ 15 kg ha-¹. In grain quality the results revealed that higher protein content (22.15%) and test weight (43.05 g) was also found in the same treatment i.e., (T5) RDF+ ZnSO4 @ 25 kg ha-¹ + Humic Acid @ 15 kg ha- ¹ (22.15%).

Integrated Application of Silicic and Humic Acid Seed Priming for Enhanced Germination and Yield of Lentil (Lens culinaris L.)

Background: Lentil is second most important nutritionally dense pulse crop of India due to its ability to fix nitrogen, helps to maintain soil fertility and increase yield of other crops grown in rotations. Seed priming is a good innovative technology for improvement of emergence and plant stand under various stress conditions and also could enhance various defense mechanisms in seeds against biotic and abiotic stresses. The present study aimed to examine the effect of seed priming with silicic acid (3 mM @18 hr), humic acid (600 ppm @18 hr) and combination of humic and silicic acid (100 ppm + 1 mM @ 16 hr), that may reduce harmful effect of stress at seedling stage and improve early seedling vigor. Methods: In this field-laboratory investigation during 2022-2023, seed quality and yield quality attributing parameters i.e. germination percentage, seed vigor index-I and II, total chlorophyll, emergence percentage, final plant stand, final plant stand emergence, plant height, secondary branches, tertiary branches, number of pod per plant, average number of pod per plant, pod cluster, seed yield per plot and yield per plot were recorded in both laboratory and field conditions. Result: The results demonstrated a positive effect of seed priming on seed quality parameters against the stress. The highest seed quality and yield quality attributing parameter was recorded in treatment (T5) combination of humic and silicic acid as compare to control. The chemical priming with combination of humic and silicic acid was found to be most effective treatment to enhance plant stand establishment against stress.

Effect of Different Levels of Humic Acid and Salicylic Acid on Yield ParameterS and Yield of Cowpea (Vigna Unguiculata)

An investigation was carried out at Narendra Deva University of Agriculture & Technology, Faizabad (U.P.) during Kharif season of 2013 to find out the effect of different levels of humic acid and salicylic acid on yield contributing parameters and yield of cowpea. The design of the experiment was Randomized Block Design and comprises of six treatments replicated thrice. The maximum pod per plant was recorded with T5 (Foliar spray of humic acid (26 ml/liter water) and 0.2% salicylic acid at 35, 55 and 65 DAS) while minimum number of pods per plant recorded in T2 (Foliar spray of humic acid (26 ml/liter water) at 25 DAS and 0.2% salicylic acid 55 DAS). Maximum pod length (75.92 cm), Maximum number of seed per pod (13.67) and 100 seed weight (13.29 g) was recorded in T5, followed by T4. The maximum seed yield per plant of 13.10 g and harvest index (42.28 %) was reported with the application of humic acid @ (26 ml/liter water) and 0.2% salicylic acid at 35, 55 and 65 DAS.

Effects of humic acid and mineral Zn fertilizer on Zn uptake and maize yield in soils formed on limestone and marl parent materials

In this study, the effects of zinc (Zn) and humic acid (HA) applications on soils (12 Aridisol soil samples) formed on limestone and marl parent materials, which are very common in Türkiye, were tested by incubation, adsorption, and greenhouse experiments. Adsorption experiments were carried out using the batch sorption technique, and the Langmuir and Freundlich isotherm parameters were calculated. In the incubation, soils were incubated with control, HA, Zn, and HA+Zn, and the DTPA-Zn was tested in five different periods (1, 7, 15, 30, and 90th days). Maize was grown for eight weeks in pots in the greenhouse. The maximum Zn adsorption for all soils ranged between 3333 and 6250 mg kg-1 in marl soils and 1042 and 5263 mg kg-1 in limestone soils, which decreased to ranges between 2631 and 5555 mg kg-1 in marl soils and 1052 and 5000 mg kg-1 in limestone soils with HA appli-cation, respectively. The desorption rate (%) of adsorbed Zn increased as the initial Zn concentration increased in all soil series formed on marl (smectite clay mineral) and lime-stone (kaolinite clay mineral) parent materials. The effects of humic acid and Zn applica-tion on the fresh and dry weights of maize were found to be statistically significant at the 5% level for marl and limestone parent material. Humic acid application increased the fresh weight of maize compared with that of the control. The highest available Zn was determined in Başkuyu series (0.79 mg kg-1) formed on marl parent material, while the lowest available Zn was obtained in Saraççeşme series (0.60 mg kg-1) formed on limestone parent material. In the greenhouse, HA increased the fresh weight of maize in soils formed on both parent materials by 0.4 and 19.6%, respectively, compared to the control. Zn fertili-zation with HA further increased the fresh and dry yields, with 12 mg kg-1 performing bet-ter. Smax (maximum Zn adsorption of the soil) parameters of soils were negatively corre-lated with EC, Pav, Kav, organic matter, silt, clay, total N, and cation exchange capacity (CEC) of the samples. Although HA alone increases the availability of Zn in plants, HA + Zn appli-cations should be applied together to obtain higher yields.

EFFECT OF HUMIC ACID AND MAXIGROW (ORGANIC FERTILIZER) ON GROWTH, FLOWERING AND YIELD OF SNAKE CUCUMBER (CUCUMIS MELO. L)

ABSTRACT: A field trial was implemented at the research center field at general directorate of agriculture, Dohuk Governorate, Iraqi Kurdistan region in summer season of (2022-2023) to find out the impact of foliar application of humic acid at three levels (0, 2, and 4) ml L-1 and Maxigrow (an organic fertilizer) with three levels (0, 1, and 2) ml L-1 and their combinations on outgrowth, flowering and harvest of local snake cucumber. The experiment was organized following a randomized complete block design (RCBD) including three replicates. The data displayed that the individual dose of humic acid at (4) ml.L-1 significantly enhanced foliage traits [number of branches, stem diameter (cm), Leaf area (cm2), plant fresh weight (g), and chlorophyll content (SPAD)] as well as increased flowering characters [number of flowers after 30 days and number of flowers after 40 days] and yielded components [fruit length (cm), fruit diameter (cm), and total yield (ton.ha-1)]. The same profound effect was exhibited by the singular dose of Maxigrow at concentration (2) ml.L-1. However, the highest mean values were produced from humic acid at concentration (4) ml.L-1 in combination with Maxigrow at concentration (2) ml.L-1 in comparison with control. The increased level of humic acid and Maxigrow is advised for organic productivity of local snake cucumber.

Aplikasi Formulasi Bahan Pembenah Tanah terhadap Beberapa Sifat Kimia Tanah Berpasir dan Produksi Tanaman Padi

Sandy soil is part of the soil fraction with low nutrient content, organic matter, and cation exchange capacity. This is due to the leaching process so that nutrients are easily lost. The research aimed to improve the chemical characteristics of sandy soil and rice crop production due to the application of humic acid and silica. This research used of Completely Randomized Design method using soil amendment materials, namely humic acid (A) at the of 60 kg/ha and silica (S) at the of 5 tons/ha consisting of 6 combinations of comparisons repeated 4 times. Variables of analysis parameters include pH, cation exchange capacity, organic matter, N-NH4+, N-NO3- and rice crop production. The data obtained were analyzed by analysis of variance (ANOVA). If the results showed a significant effect, it was continued with the Honestly Significant Difference (HSD) test at the 5% level. The results showed that the application of soil amendment in the from humic acid and silica with various treatments on sandy soil was only able to improve CEC by 3,18% and Organic-C by 0,08%. In contrast soil pH and N-available didn`t give significant results in improving soil chemical properties and rice crop production. It`s recommended to conduct further research on the dose used in soil amendments so that it can effect nitrogen parameters and rice crop production in sandy soil. Keywords: humic acid, silica, sandy soil

Alone or Combined Effect of Seaweed and Humic Acid Applications on Rapeseed (Brassica napus L.) under Salinity Stress

Organic fertilisers and biostimulants play a very important role in the germination, seedling stage, yield and quality of plants. Seaweed and humic acid are organic substances known for their positive effects. Therefore, the aim of this study was to investigate the effects of humic acid, seaweed extract and their combined applications against salt stress in oilseed rape at the seedling development stage. The effects of foliar application of seaweed extract (SW1, SW2, SW3) (0, 10, 20 mL), humic acid (HA1, HA2, HA3) (0, 10, 20 mL) and SW + HA (SW1 + HA1, SW2 + HA2, SW3 + HA3) (0, 10(5 + 5 mL L− 1 SW + HA), 20 mL L− 1 (10 + 10 mL L− 1 SW + HA)) on resistance to salt concentrations (S1, S2, S3) (0, 50, 100 mM) in oilseed rape cultivar (Elvis) under greenhouse conditions. In this study, seedling length (SL), root length (RL), total chlorophyll (Total Chl), carotenoids (Crt), electrolyte leakage (EL), malondialdehyde (MDA), superoxide dismutase (SOD), total phenolic compounds (TPC), relative water content (RWC) and proline (Pro) parameters were examined. Both applications played a significant role in reducing the negative effects of salt stress on all parameters studied. The combined application of SW + HA resulted in a remarkable increase in SL, RL TPC, SOD and RWC. In particular, the SW3 + HA3 dose played a more effective role in the antioxidant protective mechanism against stress. According to the PCA analysis, the studied parameters could be divided into 3 different groups. It was concluded that SW and HA can be evaluated as an effective natural, eco-friendly material that can be used to increase the resistance of plants to salt stress. In conclusion, in this study all applications are compared with each other, it has been determined that SW + HA is more effective application in reducing the effects of salt stress than others.

Effect of Soil and Foliar Application of Humic Acid on Nutrient Uptake, Grain and Straw Yield of Black Gram (Vigna mungo L.) under Inceptisols

Black gram is a type of legume that is widely cultivated and consumed in various parts of the world. It is believed to have originated in the Indian subcontinent and is one of the oldest cultivated legumes in the world. The field experiment was carried out to during kharif season of the year 2022 at departmental farm of Soil Science and Agricultural Chemistry, College of Agriculture, Latur. The experiment was laid out in randomized block design with three replications and eight treatments viz., T1 (RDF), T2 (RDF + Foliar application of humic acid @ 0.2 % at 20 & 35 DAS), T3 (RDF + soil application of humic acid @ 10 kg ha-1), T4 (RDF + soil application of humic acid @ 15 kg ha-1), T5 (RDF + soil application of humic acid @ 20 kg ha-1), T6 (T3 + foliar application of humic acid @ 0.2% at 20 & 35 DAS), T7 (T4 + foliar application of humic acid @ 0.2% at 20 & 35 DAS), T8 (T5 + foliar application of humic acid @ 0.2% at 20 & 35 DAS). The field study indicated that the nutrient uptake and content and grain and straw yield of black gram crop were significantly influenced due to soil and foliar application of humic acid and RDF. The uptake of N, P and K were recorded at harvest. Significant and maximum uptake of N, P and K were noticed with application of treatment T8 (RDF + soil application of humic acid @ 20 kg ha-1+ foliar application of humic acid @ 0.2% at 20 and 35 DAS), whereas the T1 (RDF) showed least values. grain and straw yield significantly affected due to T8 (RDF + soil application of humic acid @ 20 kg ha-1 + foliar application of humic acid @ 0.2% at 20 and 35 DAS) and the lowest grain and straw yield were recorded in T1 (RDF). Thus, it can be concluded that the soil and foliar application of humic acid increase the nutrient uptake and grain and straw yield. The significantly superior result recorded by treatment T8 (RDF + soil application of humic acid @ 20 kg ha-1 + foliar application of humic acid @ 0.2% at 20 and 35 DAS) next to this treatment T7 (RDF + soil application of humic acid @ 10 kg ha-1 + foliar application of humic acid @ 0.2% at 20 and 35 DAS) was best option. The significant increase in grain and straw yield of black gram was due to application of RDF with soil and foliar application of humic acid which mitigates scarcity, increased absorption effectively and increased photosynthetic activity which leads to higher grain and straw yield.