Levels Of Humic Acid Research Articles

Effect of Humic Acid Application Methods on Nutrients Availability and Growth and Yield of Okra(ABELMOSCHUS ESCULLANTUS L.)

A field experiment was conducted at the Agricultural Research Station, College of Agriculture, University of Basrah during the growing season of 2021- 2022 to study the effect of adding humic acids either to soil or spraying on plant along with recommended chemical fertilizers(NPK) on availability of N, P, and K and EC and pH of soil as well as growth and yield of okra. The results showed an increase in the availability of N,P and K by adding humic acid to the soil while spraying of humic acid had no clear differences with chemical fertilizers treatments. Addition of humic acid to soil decreased EC while addition as foliar application increase EC of soil. Addition of humic acid along with chemical fertilizers to soil or spraying on plant led to an increase in concentrations of N, P, and K in the leaves and their uptake with superiority of spraying treatment over soil application treatments. Increasing humic acid level spraying on plant from 0.5 to 1.0gL-1 significantly decreased N,P and K concentrations and uptakes. Similar findings were obtained for dry matter and fruits yield. The lower the level of humic acid ,The higher the dry matter and yield. The highest value of okra fruit yield 2791.06 kgha-1 was obtained with treatment involved spraying of 0.5gL-1 humic acid plus full recommended chemical fertilizers.

Effect of Humic Acids Extracted From Different Organic Sources and Inoculation of Bacillus Subtilis or Aspergillus Niger in Alkaline Phosphatase Activity in Calcareous Soil

Humic acids have received a large attention of researching and development as amendments for poor fertility conditions and deteriorating physical properties, since the process of extracting is an easy common process to implement, as well as dilution of these acids with water enables to be used at economically acceptable levels over large areas. It is necessary to notice that the properties of these acids depending on the organic source and the concentration added to the soil.A laboratory experiment was conducted at the department of soil Sciences and water resources, collage of Agriculture ,University of Basrah ,Iraq to demonstrate the effect of humic acids extracted from different sources and inoculation with Bacillus subtilis or Aspergillus niger on alkaline phosphatase activity in calcareous soil calcareous, southern Iraq. Humic acids extracted from wheat straw, alfalfa leaves, goat manure, and poultry manure which composted previously . Humic acid levels were 0, 25 and 50 L ha-1 .The soil also inoculated with Bacillus subtilis or Aspergillus niger, then samples were incubated at 28±2°C. After 7 or 30 days of incubation the activity of alkaline phosphatase was estimated . Enzyme phosphatase activity was increased in soils treated with humic acid as compared to control with highest activity at Poultry manure (391.54 µg p-nitrophenol gm-1 soil.1h-1).The results also indicated that increasing the level of humic acid significantly increased enzyme activity. For soil treated with Bacillus subtilis and Aspergillus niger , phosphatase activity increased-as compared to control with a higher activity at Bacilluas subtilis (373.1 µg p-nitrophenol gm-1 soil.1h-1).

Effect of Humic acid and levels of Zinc and Boron on Chemical Behavior of Zinc in Calcareous Soil

There are global concerns about the significant increase in the concentrations of heavy elements due to the increase in agricultural, urban and industrial activities, which poses a threat to the natural environment and humans. This study focused on studying the addition of humic acid and different levels of zinc on the presence of zinc in the soil in its different forms and its readiness for the plant to find the best concentration and with the presence or absence of humic acid. This study was carried out on the sunflower crop, as zinc was added at levels of (0, 15 and 30) kg h-1 and humic acid at two concentrations, (0 and 50) kg h-1. Zinc was extracted successively and total and available zinc was measured. The results indicated: Concentration of total and available Zinc associated with carbonate minerals, with oxides, and with organic matter in soil increased with increasing levels of Zinc added to soil, reaching 8.638, 1.049, 1.971, 1.658 and 1.625 mg kg-1 soil, respectively. The effect of added humic acid was significant in reducing the concentrations of total Zinc, Zinc bound to carbonate minerals, bound to oxides and residues. The maximum concentrations in case of not adding acid reached 9.313, 1.8957, 1.424, and 4.300 mg kg-1 soil, respectively, while the effect was positively in increasing available concentration associated with organic matter, as concentration in case of adding humic acid reached 0.851 and 1.4584 mg kg-1 soil, respectively. In the case of adding humic acid, this study is considered good for the results it showed in increasing the available zinc with the presence of humic acid, which is reflected in the plant growth and maintaining this element within the recommended concentrations. We determined Zn speciation in the soil system and evaluated the effects of humic acid application on the basic soil properties and Zn bioavailability.

Effects of tomato straw fermentation on nutrients and bacterial community structure

Unsustainable straw treatment methods detrimentally affect the environment and ecology. Aerobic fermentation (AE) and anaerobic fermentation (AN) are environmentally friendly treatments that better utilise straw resources. In this study, high-throughput sequencing was used to investigate the effects of AE and AN on nutrient content and microbial community structure during tomato straw fermentation. Nitrate nitrogen, available phosphorus, available potassium, and fulvic acid contents following AE were 1250.04 mg/kg, 80.34 %, 161.39 %, and 49.31 %, respectively, which were higher than those following AN. Ammonium nitrogen, humic acid, and humic substance levels following AN were 309.07 %, 31.18 %, and 17.38 %, respectively, which were higher than those following AE. Firmicutes (24.76 %) and Actinobacteria (12.93 %) were more abundant following AE, whereas Proteobacteria (33.82 %) and Bacteroidetes (33.82 %) exhibited higher abundance following AN. AE more effectively eliminated pathogenic bacteria (22.01%–0.26 %) and encouraged stronger interactions between dominant bacterial genera. Redundancy and Mantel test analyses revealed that electrical conductivity and temperature were the most important environmental factors affecting bacterial communities in AE and AN, respectively. AE had a stronger effect on effective nutrient release from tomato straw, implying its greater application potential as a fertiliser. Overall, our study provides a theoretical basis for the optimisation of fermentation methods and processes.

Humic acid and grafting as sustainable agronomic practices for increased growth and secondary metabolism in cucumber subjected to salt stress

Salinity stress poses a significant treat to crop yields and product quality worldwide. Application of a humic acid bio stimulant and grafting onto tolerant rootstocks can both be considered sustainable agronomic practices that can effectively ameliorate the negative effects of salinity stress. This study aimed to assess the above mentioned ameliorative effects of both practices on cucumber plants subjected to saline environments. To attain this goal a factorial experiment was carried out in the form of a completely randomized design with three replications. The three factors considered were (a) three different salinity levels (0, 5, and 10 dS m−1 of NaCl), (b) foliar application of humic acid at three levels (0, 100, and 200 mg L−1), and (c) both grafted and ungrafted plants. Vegetative traits including plant height, fresh and dry weight and number of leaf exhibited a significant decrease under increasing salinity stress. However, the application of humic acid at both levels mitigated these effects compared to control plants. The reduction in relative water content (RWC) of the leaf caused by salinity, was compensated by the application of humic acid and grafting. Thus, the highest RWC (86.65%) was observed in grafting plants with 0 dS m−1 of NaCl and 20 mg L−1 of humic acid. Electrolyte leakage (EL) increased under salinity stress, but the application of humic acid and grafting improved this trait and the lowest amount of EL (26.95%) was in grafting plants with 0 dS m−1 of NaCl and 20 mg L−1 of humic acid. The highest amount of catalase (0.53 mmol H2O2 g−1 fw min−1) and peroxidase (12.290 mmol H2O2 g−1 fw min−1) enzymes were observed in the treatment of 10 dS m−1 of NaCl and 200 mg L−1 humic acid. The highest amount of total phenol (1.99 mg g−1 FW), total flavonoid (0.486 mg g−1 FW), total soluble carbohydrate (30.80 mg g−1 FW), soluble protein (34.56 mg g−1 FW), proline (3.86 µg g−1 FW) was in grafting plants with 0 dS m−1 of NaCl and 200 mg L−1 of humic acid. Phenolic acids and phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) enzymes increased with increasing salinity and humic acid levels. Contrary to humic acid, salt stress increased the sodium (Na+) and chlorine (Cl−) and decreased the amount of potassium (K+) and calcium (Ca2+) in the root and leaf of ungrafted cucumber. However, the application 200 mg L−1 humic acid appeared to mitigate these effects, thereby suggesting a potential role in moderating physiological processes and improving growth of cucumber plants subjected to salinity stress. According to the obtained results, spraying of humic acid (200 mg L−1) and the use of salt resistant rootstocks are recommended to increase tolerance to salt stress in cucumber. These results, for the first time, clearly demonstrated that fig leaf gourd a new highly salt-tolerant rootstock, enhances salt tolerance and improves yield and quality of grafted cucumber plants by reducing sodium transport to the shoot and increasing the amount of compatible osmolytes.

Soil amendment and N fertilization strategies to improve C sequestration and storage in soil aggregates

AbstractManagement can affect soil quality through changes in carbon (C) stock, especially in protected C fractions of soil aggregates. Soil aggregation and C sequestration may be improved with soil correction (liming and gypsum) and nitrogen (N) fertilization, but it is not clear how these factors might interact to affect humic substances. The objective of the study was to evaluate the effects of calcium (Ca), magnesium (Mg), and N fertilizatilizer amendments on the accumulation of C, N, and humic substances in soil aggregates from an Oxisoil in Brazil. The production system was no‐till soybean [Gycine max (L.) Merr] double‐cropped with maize (Zea mays L.) and intercropped with forage grass since 2016. Treatments were no amendment, lime only, and lime + phosphogypsum, factorially arranged with and without annual N fertilization of maize. Soil was collected at 0–10, 10–20, 20–40, and 40–60 cm 6 years after initiation of the experiment. The combination of lime, gypsum, and N led to 13% greater total C stock and 20% greater total N stock within the 0–60 cm soil profile than the control. Levels of fulvic acid (FA) and humic acid (HA) were similar among aggregate classes, but humin was greatest in larger aggregates. Liming plus N decreased FA and HA, but gypsum application mitigated this negative effect. Application of limestone, gypsum, and N increased humin, mainly in the soil surface (0–10 cm). Soil C storage and stabilization was enhanced in large soil aggregates with the combined use of lime, gypsum, and N fertilization in humid tropical soils.

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.

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.

Enhanced humification via lignocellulosic pretreatment in remediation of agricultural solid waste

Stover and manure are the main solid waste in agricultural industry. The generation of stover and manure could lead to serious environmental pollution if not handled properly. Composting is the potential greener solution to remediate and reduce agricultural solid waste, through which stover and manure could be remediated and converted into organic fertilizer, but the long composting period and low efficiency of humic substance production are the key constraints in such remediation approach. In this study, we explore the effect of lignocellulose selective removal on composting by performing chemical pretreatment on agricultural waste followed by utilization of biochar to assist in the remediation by co-composting treatment and reveal the impacts of different lignocellulose component on organic fertilizer production. Aiming to discover the key factors that influence humification during composting process and improve the composting quality as well as comprehensive utilization of agricultural solid waste. The results demonstrated that the removal of selective lignin or hemicellulose led to the shift of abundances lignocellulose-degrading bacteria, which in turn accelerated the degradation of lignocellulose by almost 51.2%. The process also facilitated the remediation of organic waste via humification and increased the humic acid level and HA/FA ratio in just 22 days. The richness of media relies on their lignocellulose content, which is negatively correlated with total nitrogen content, humic acid (HA) content, germination index (GI), and pH, but positively correlated with fulvic acid (FA) and total organic carbon (TOC). The work provides a potential cost effective and efficient framework for agricultural solid waste remediation and reduction.

Humic acid application on soil stability indices and enzyme activity at different bell pepper water requirements

Use of organic materials helps in reducing the consumption of chemical fertilizers, contributing to the sustainability of agricultural ecosystems. Humic acid can improve soil structure, especially in soils with low clay content, aiding in water retention and enhancing water absorption by plants. This characteristic has led to the attention of humic acid application in drought stress, particularly in arid soil regions. The present study aimed to investigate the simultaneous effects of humic acid and plant water requirements on the physical and biological properties of soil under bell pepper cultivation. The factorial experiment was conducted in a completely randomized block design with three levels of humic acid: 0 (HA0), 2 (HA2), and 4 (HA4) g/Kg of soil and four levels of plant water requirements: 60 (L60), 80 (L80), 100 (L100), and 120 % (L120), with four replications under greenhouse conditions. Bell pepper seedlings were transferred to 10 Kg pots after applying humic acid treatments and after the establishing of seedlings, plant water requirement treatments were applied for 80 days. During this period, plants were maintained at a temperature of 25 degrees Celsius during the day, 18 degrees Celsius at night, and a relative humidity of 75%, with a carbon dioxide concentration of 80 milligrams per liter. The results of this study showed that treatments L80HA4, L100HA4, and L120HA4 had the most significant impact on improving soil physical properties, such as normal stability index, total soil stability index, mean weight diameter of soil particles, soil particle stability, geometric mean diameter of soil particles, and reduction in soil particle destruction percentage. The highest values of wet and dry weight diameter of soil particles were observed in treatment L100HA4, which were 42.92%, 74%, and 67.01% higher, respectively, compared to the control (L60HA0). In contrast, the highest percentage of soil particle destruction was observed in treatment L60HA0, showing a 32.90% increase compared to treatment L100HA4. Furthermore, the best performance of bell pepper yield was observed in treatments L80HA4, L100H4, and L120HA4, although the differences between treatments were not statistically significant. The application of humic acid, in addition to improving bell pepper yield, increased water use efficiency and reduced water use. The lowest yield (3283 Kg/ha) and the lowest water consumption (3584 cubic meters/ha) were observed in treatments L60HA0 and L60HA4, respectively. Additionally, the results showed that the highest water use efficiency observed in L80HA4 treatment (7.45 Kg/m³), while the lowest was in L60HA0 treatment (0.80 Kg/m³). Moreover, humic acid significantly influenced the activity of soil enzymes, including soil phosphatase and urease. With more application of humic acid, soil moisture retention, microbial biomass carbon, urease, phosphatases activities increased. However, in treatments with full water requirements and 20 percent more than plant water requirements, enzyme activities decreased.

Suların Klorla Dezenfeksiyonunda Trihalometan Oluşumuna Hümik Asit ve Bromürün Etkisi

Chlorination is one of the most important methods used in water disinfection. Chlorine reacts with natural organic substances in water and causes the formation of disinfection byproducts that might cause health problems. The predominant by-product of chlorination is trihalomethanes. Humic substances, which make up the majority of natural organic substances, are the primary precursors of trihalomethanes. In this study, the effect of different doses of chlorine on the formation of chloroform, bromodichloromethane, dibromochloromethane and bromoform in the presence of natural organic matter and bromide in drinking water was evaluated. Artificial raw water samples prepared with the addition of 2, 3 and 5 mg/L humic acid representing natural organic matter were subjected to chlorination at doses of 1, 2 and 3 mg/L and analysed on the 0th, 3rd and 7th day. The only trihalomethane formed was chloroform with a concentration of 20.52-131.13 μg/L. Increased humic acid and chlorine levels resulted in increased chloroform content. Free chlorine in the water caused chloroform formation to continue even on the 7th day. Accordingly, the amount of chloroform formed increased with the contact time. While the chlorine dose was constant, increased humic acid resulted in decreased free chlorine. To evaluate the effect of bromide on trihalomethane formation, 200 μg/L bromide was added to 2 mg/L humic acid containing water, and 1 mg/L and 2 mg/L chlorination was applied. At the end of the chlorination process in bromide-free waters, only 23.46-41.90 μg/L of chloroform was formed. In the presence of bromide, chloroform, bromodichloromethane, dibromochloromethane and bromoform were formed and the total trihalomethane level increased to 50.03-85.59 μg/L. While the ratio of brominated trihalomethane increased, the amount of chlorinated species decreased.

Impact of Diverse Agricultural Land Uses on Soil Organic Matter Fractions: A Comprehensive Evaluation

Organic matter is a crucial component of soil that influences various soil properties and functions, including nutrient cycling, soil structure, water holding capacity and microbial activity. Different agricultural land uses significantly influence the quantity and quality of soil organic matter (SOM) fractions. The primary constituent of SOM is humic substances, also known as humus. These are stable compounds originating from the decomposition of organic matter derived from plants, animals, and microorganisms. The soil humic fraction is categorized into humic acid (HA), fulvic acid (FA) and humin (HN) based on the solubility in acid and alkaline medium. The structural arrangement, chemical constitution and stability of the humic substances in soil are affected by various factors, including climate, parent material, altitude, vegetation and the management practices employed in the area. In this context the present study was proposed to assess the impact of various agricultural land use systems on humic acid, fulvic acid and humin fraction in soils of different agro-ecological units (AEUs) of southern Kerala. The study focused on specific AEUs in southern Kerala, including the southern coastal plain (AEU 1), Onattukara sandy plain (AEU 3), southern laterites (AEU 8), south central laterites (AEU 9) and southern and central foothills (AEU 12). Within each AEU, various agricultural land use categories such as, coconut, rice, rubber and uncultivated land were selected as specific focal points for this investigation. The HA, FA and HN content in soil exhibited varying ranges across different AEUs, ranging from 0.57 to 2.06, 0.73 to 2.33, and 0.62 to 1.59 per cent respectively. Among the various land uses, rubber exhibited significantly higher levels of HA (1.72%), FA (2.01%) and HN (1.44%) compared to coconut, rice and uncultivated land. Among the different organic matter fractions, FA (32.30-36.18 %) contributed more towards SOM than HA (29.40-32.51 %) and HN (26.43-29.25 %).

Response of Okra Varieties to Different Fertilizer Level of Humic Acid

Background and Objective: Poor soil fertility is a great limitation to crop production. The adverse effects of chemical fertilizer and the unavailability of organic fertilizer in large quantities are another challenge. The research was conducted at the Research Farm of Ekiti State University, Ado-Ekiti, Nigeria to examine the effects of appropriate doses of humic acid (HA) fertilizers for maximum performance of okra.
 Materials and Methods: The experiment was laid out in Randomized Complete Block Design (RCBD) with three replicates. The two factorial experiments comprise four levels of humic acid fertilizer (0, 5.0, 10.0, and 15.0 g HA plant-1) and NPK 15-15-15 (150 kg hac-1), and two okra varieties. The two okra varieties were allocated to main plots while the fertilizer levels were allocated to sub-plots. The collected data on final plant height (cm), the number of leaves per plant, the number of fruits per plant, the weight of fresh fruit per plant (g), the fruit length (cm), the leaf area (cm3), the fruit diameter (cm), and the stem diameter (cm) and analyzed with the IRRI STAR Software.
 Results: The result showed that the traits measured were significantly different for (HA) levels and NPK fertilizers. The varieties were significantly different for the measured traits except for leaf area, fruit diameter, and fruit length while the varieties x amendment levels were significant for plant height, leaf area, fruit diameter, and stem diameter while others are not significant. The measured traits increases as the humic acid levels increase. It was observed that the plants that received 15.0 g HA plant-1 performed better, followed by 10.0g HA plant-1 and NPK 15-15-15 respectively. However, the differences in the plants that received 5.0g HA plant-1 and 7.5g HA plant-1 were minute.
 Conclusion: It is therefore concluded that 5.0g HA plant-1 should be applied for optimal okra yield.

Correlation and Pathway Analysis and their Applications to Improve Yield in Bread Wheat Under Humic Acid Conditions

This study aimed to know the relationship between growth traits and yield components with yield by studying some statistical and genetic parameters in addition to correlation and path analyses . The study included fifteen types of bread wheat (Sham 8, Aba 99, Kraita, Al_ Ezz, Aba 95, Mexibak, Sham 6, Abu Ghraib 3, Al-Fath, Intisar, Latifa, Tamouz3, Bohouth 22, and Al_Rasheed) under the influence of three levels of humic acid (0, 20 and 40 kg.h−1) using the Randomized complete block design to the arrangement of split plots with three replicates and characteristics, the number of days to heading ofspikes, the area of the flag leaf, plant height, number of active tillers, number of grains of the spike, 1000 grains weight and the total yield. The most important results were summarized as: The presence of high genetic variance compared to environmental variance, which was reflected in the high value of heritability in the broad sense, and that the coefficient of environmental variation was low compared to the coefficient of genetic and phenotypic variation, which was average, and that the expected genetic improvement as a percentage was average for all studied traits except number of days to heading trait varying levels of humic acid. We conclude from this that the third level can be considered a good and suitable environment through direct selection of the two characteristics number grains per spike and grains thousand weight to improve the yield in the future.

Boosted micropollutant removal over urchin-like structured hydroxyapatite-incorporated nickel magnetite catalyst via peroxydisulfate activation

In this work, urchin-like structured hydroxyapatite-incorporated nickel magnetite (NiFe3O4/UHdA) microspheres were developed for the efficient removal of micropollutants (MPs) via peroxydisulfate (PDS) activation. The prepared NiFe3O4/UHdA degraded 99.0 % of sulfamethoxazole (SMX) after 15 min in 2 mM PDS, having a first-order kinetic rate constant of 0.210 min−1. In addition, NiFe3O4/UHdA outperformed its counterparts, i.e., Fe3O4/UHdA and Ni/UHdA, by giving rise to corresponding 3.6-fold and 8.6-fold enhancements in the SMX removal rate. The outstanding catalytic performance can be ascribed to (1) the urchin-like mesoporous structure with a large specific surface area and (2) the remarkable synergistic effect caused by the redox cycle of Ni3+/Ni2+ and Fe2+/Fe3+ that enhances multipath electron transfers on the surface of NiFe3O4/UHdA to produce more reactive oxygen species. Moreover, the effects of several reaction parameters, in this case the initial solution pH, PDS dosage, SMX concentration, catalyst loading, co-existing MPs and humic acid level on the catalytic performance of the NiFe3O4/UHdA + PDS system were systematically investigated and discussed in detail. The plausible catalytic mechanisms in the NiFe3O4/UHdA + PDS system were revealed via scavenging experiments and electron paramagnetic resonance analysis, which indicated a radical (•OH and SO4•−) as the major pathway and a nonradical (1O2) as the minor pathway for SMX degradation. Furthermore, NiFe3O4/UHdA exhibited fantastic magnetically separation and retained good catalytic activity with a low leached ion concentration during the performance of four cycles. Overall, the prepared NiFe3O4/UHdA with outstanding PDS activation could be a promising choice for the degradation of persistent organic pollutants from wastewater.

Effect of Bio-fertilizer, Humic Acid and Sea Algae Extract on Growth and yield of Sudan grass (Sorghum sudanese L.)

A field experiment was conducted during the spring agricultural season of 2021 in two locations, the first in Al-Tilga (10 km northwest of Mosul) and the second in Al-Shuhada (35 km west of Mosul). The experiment was applied according to a randomized complete block design (R.C.B.D.) with a split-plot system. The levels of bio-fertilizer occupied the main plots, and the levels of humic acid and seaweed extract (Alggren-Twin) were secondary plots in three replications. The two factors of the study were as follows: The first factor was biofertilizer (Bactofed) at two levels of zero and 750 ml / 1000 L of water/ha. The second factor is four levels of two levels of seaweed extract with the trade name (Algaren Twin): 3 and 6 ml /L of water. The third and fourth levels are 8 and 16 kg/ha of humic acid. The results of the study were as follows: The addition of bio-fertilizer caused a significant increase in plant height, the yield of fresh and dry forage, the number of dahlias per plant, the weight of panicles grains, and grain yield of individual and total plants in both locations. Also, the addition of seaweed extract and humic acid increased in most of the studied traits to achieve the highest average for most traits and in both locations at the level of humic acid 16 kg/ha. Keywords: Boi-fertilizer; Humic acid; Sea Algae; Sudn agrass; Sorghum sudanense L.

Performance evaluation of the effect of humic acid on Anammox granular sludge: Apparent morphology, nitrogen removal and microbial community

Humic acid (HA) is a typical refractory organic matter, so it is of great significance to investigate its effect on the performance of Anammox granular sludge. When the dosage of HA ≤ 50 mg/L, HA promotes the total nitrogen removal rate (NRR) to 1.45 kg/(m3·day). When HA was between 50 and 100 mg/L, the NRR of Anammox was stable. At this time, the adsorption of HA causes the sludge to gradually turn from red to brown, but the activities of heme and enzymes showed that its capacity was not affected. When HA levels reached 250 mg/L, the NRR dropped to 0.11 kg/(m3·day). Moderate HA levels promoted the release of extracellular polymeric substance (EPS), but excessive HA levels lead to a decrease in EPS concentrations. HA inhibited Anammox activity, which indirectly hindered the transmission of substrate and accumulated substrate toxicity. Although HA promoted the increase of heterotrophic microbial abundance in Anammox system, the microbial diversity decreased gradually. With the increase of HA concentration, the abundance of Candidatus_Brocadia, the main functional microorganism of Anammox system, decreased gradually, while the abundance of Candidatus_Kuenenia increased gradually.

Effect of Soil Addition of Humic, Fulvic Acids and Irrigation Water Salinity on the Yellow Corn Zea mays L. Growth

A field experiment was carried out during the two spring seasons 2020/2021 in an agricultural field, located on the banks of the Euphrates River in Al-Muthanna Governorate, which is 4 km away from Al-Muthanna University, between latitudes 45°14′58″ and longitudes 31°19′33″, to study the effect of adding humic and fulvic organic acids and irrigation water salinity on the growth traits of corn crop Zea mays L., in an experiment whose treatments included three levels of concentrations of a mixture of organic acids (humic and fulvic) which were 0, 20 and 40 liters of ha-1, four levels of electrical conductivity of the irrigation water used in the irrigation process, it was less than 2.0 dSiemens m-1 using pure water RO mixture with river water, and 4.0, 6.0 and 8.0 dSiemens m-1 using a mixture of tap water and river water. The results showed a significant effect between irrigation water salinity levels on plant height, where the transaction decreased by 8.0 dSiemens m-1, significant effect between the levels of humic and fulvic organic acids in the leaf area cm2, where the treatment exceeded 20 liters ha-1, there was a significant interaction between humic and fulvic acid levels and irrigation water salinity levels, the combination (40 L × salinity comparison) a high leaf area and dry matter.

Effect of Foliar Fertilization with Humic Acid and Garlic Extract on Growth and Yield of Broccoli and its Content of some Secondary Metabolites

An experiment was conducted in one of the open fields of the Department of Horticulture and Landscape Engineering, College of Agriculture,Al-Qasim Green University for the autumn season 2021-2022. The experiment included a study of three levels of humic acid (0, 2, 4) ml / liter and three levels of garlic extract (0, 10, 20) ml / liter and the interaction between them in the growth and yield of broccoli plant and its content of total phenols and flavonoids. A factorial experiment (3×3) was conducted according to the split plot design and with three replicates, where each replicate contains 9 treatments. Test the least significant difference L.S.D at the level of 5%. The results showed the humic acid at a concentration of 4 ml / liter in excelled and gave the highest plant height of 57.60 cm, the number of leaves 17.46 leaves / plant, the percentage of dry matter 19.06%, the diameter of curd 23.24 cm, the weight of curd 0.736 kg, and the total amount of phenols in the leaves 1.93 mg / kg. Humic treatment at a concentration of 2 ml / L was significantly excelled in the total amount of phenols in the pink disc at a rate of 1.98 mg / kg. The garlic extract at a concentration of 20 ml/L recorded significantly excelled in recording the highest plant height of 58.42 cm, the percentage of dry matter 19.40%, the curd diameter 23.12 cm, and the curd weight 0.766 kg. In the leaves, it reached 38.15 mg / kg,As for the interaction treatments, most of the interaction treatments recorded significantly excelled in most of the studied traits, but the best interaction treatments were H3G3, which recorded the highest number of leaves 13.60 leaves and the percentage of dry matter 19.73% and the diameter of the pink disc 25 cm and the weight of curd 0.870 kg.While treatment H2G2 recorded the highest value of total phenols in leaves 2.07 mg / kg and treatment H3G2 recorded the highest value of flavonoids in leaves 38.37 mg / kg. Treatment H2G1 recorded the highest value of total phenols in curd amounted to 2.10 mg/kg, and treatment H3G1 recorded the highest value of flavonoids in curd amounting to 38.61 mg/kg.

Humic Acid Improves the Resilience to Salinity Stress of Drip-Irrigated Mexican Lime Trees in Saline Clay Soils

Organic fertilization improves soil fertility and ameliorates the deleterious effects of accumulated salts in soil for sustainable agricultural production. This research was carried out on thirteen-year-old Mexican lime trees to study the effect of humic acid (HA), applied as soil (10, 20 or 30 mL·tree−1) and foliar (0.1 or 0.2%) applications, on soil fertility, tree growth, productivity and fruit quality. The experiment was conducted during the 2020 and 2021 seasons in a randomized complete block design of twelve treatments with three replicates with two trees each. Soil and foliar applications of HA were performed once and twice a month in Marsh, May and July, respectively. HA enhanced the soil’s N, P, K, Ca, Mg, Fe, Mn, Zn, Cu and B availability and microbial activity, in addition to improved tree growth, canopy size, leaf chlorophyll and nutrient contents with reduced proline levels. The total yield and number of fruit per tree were increased with increased HA levels. Fruit weight, juice and soluble solids were also increased. The best results were achieved with the combined soil (30 mL·tree−1) and foliar (0.2%) applications of HA, which indicated a great potential to alleviate the effects of salinity stress on Mexican lime growth and productivity.