Levels Of Humic Acid Research Articles

An assessment of composting conditions, humic matters formation and product maturity in response to different additives: A meta-analysis

Humic matters (HMs), including humic substance (HS), humic acid (HA) and fulvic acid (FA), and germination index (GI), are essential indices of compost maturity and stability. While traditional composting practices can produce poor final products, the application of different additives (such as physical, chemical, and microbial types) is a possible way to hasten the composting process and improve the quality of the compost products. Yet, there is a deficiency of comprehensive and quantitative analysis of how additives affect physicochemical parameters, HMs formation, maturity, and stability of compost products. Here, a meta-analysis was conducted based on 494 paired observations to explore the response pattern of compost physicochemical factors and maturity indices to different additives during composting. The results indicated that applied additives increased the level of HS, HA, GI, total nitrogen (TN), temperature, and pH by 41.3%, 73.4%, 16.6%, 19.4%, 9.63%, and 7.33%, respectively, across all the observations, compared to the control composts. Meanwhile, the level of FA, total organic carbon (TOC), moisture content (MC), and C/N were lower by −37%, −20.8%, −18.9%, and −20.5% than in the control composts. Composting duration contributed to considerable degrees of variation in HMs’ response to different additives (p < 0.05). Also, composting factors (feedstock, additive types, and bulking agents) were effective regulators of the response of HMs to different additives. Accordingly, adjusting the additives, process duration, and composting factors can positively impact the amount of HMs and nutrients in the compost products. Eventually, the outcomes of this study can support the selection, improvement, and application of additives to promote the quality and stability of the compost products.

Distribution of macro- and micronutrients in leaves, roots, and scapes of gerbera affected by calcium and humic acid

Different levels of humic acid (HA) (0, 100, 500, and 1000 mg L−1) and Ca (3.5 and 7 meq/L) were applied to growth media. A multi-level factorial experiment with a completely randomized design was employed with three replicates to evaluate interaction effects. Macro- and micro-nutrient contents were measured in leaves, roots, and scapes of gerbera. Five hundred mg/L HA increased macro- and micronutrients (P, N, K, Mg, Ca, Fe, and Zn) contents of leaves, roots, and scapes. High HA levels reduced some nutrient contents. The 7 meq/L Ca significantly increased Fe and Zn contents of leaves and roots and K and Mg contents of roots, and had no significant effect on other macronutrients. The results showed the importance of Ca-HA treatment in gerbera cultivation through increasing nutrient concentration. The Ca-HA treatment exhibited significant effects on nutrient uptake of gerbera. Ca and HA combination was more effective, especially with 7 meq Ca and 500 mg/L HA, than the low Ca and HA content. The 7 meq/L Ca and 500 mg/L HA increased N, Ca, K, and Zn concentrations in leaves, and Ca, P, Mg, Fe, and Zn concentrations in scapes, and Zn in roots, whereas this trend for Fe, Mg, and N in leaves and P and Mg in roots was found in 100 and 1000 mg/L HA. Conclusively, nutrients’ absorbtion and accumulations in scape and leaves were higher than in roots and were higher when Ca was applied in 7 meq/L with HA at 500 mg/L to gerbera.

Humic acid and potassium feldspar improve growth, yield and head quality of broccoli grown under saline water irrigation

An open field experiment was carried out during the two successive seasons of 2018/2019 and 2019/2020 respectivly, at Badr City, El-Beheira, Egypt to study the effect of saline irrigation water on grwoth, yield and quality of broccoli (Brassica oleraceae L var. Italica) cultivar “Marathon” grown in sand soil. During soil preparation, soil was supplied with 2 ton of gypsum and 7.8 ton of compost/fed., in combination with 2 levels of potassium feldspar (141- 424 kg/fed.), to supplement sand soil with 100 and 130 unites of K2O. Three levels of humic acid (2, 4 and 6 L humic acid/fed.) were foliar sprayed after two weeks post transplanting at 10 days intervals. Plants were arranged in three replicates using randomized complete blocks design. Control was supplied with full NPK mineral fertilizers, as recommended, and irrigated with saline irrigation water. Our results show that saline water decreased growth, yield and quality of control broccoli plants in the two growing seasons. On the other hand, application of humic acid and organic soil amendments enhanced performance of broccoli plants grown under saline water.

Effect of Foliar Spray of Humic Acid on Root Growth, Yield Components and Quality in Redgram (Cajanus cajan )

The present study examined the effect of foliar spray of humic acid on root Growth, yield components and quality in Redgram (Cajanus cajan ).The study was conducted during Kharif 2015-16 at Main Agricultural Research Station, UAS, Raichur by using randomized block design. The effectiveness of humic acid was studied with different levels as T1 - Humic acid liquid 15% @ 1.0 ml/l of water, T2 - Humic acid liquid 15% @ 1.5 ml/l of water, T3 - Humic acid liquid 15% @ 2.5 ml/l of water, T4 - Humic acid liquid 15% @ 4.0 ml/l of water, T5 - Planofix 4.5 % @ 20ppm and T6 - as a control. Redgram root growth including root length, shoot length, root dry weight , shoot dry weight , leaf area, dry matter production, flower drops, minerals content (quality), and yield components were measured at 60,90 DAS and at harvest, respectively. Significant differences (p&lt;0.05) were observed for all the above mentioned parameters across the humic acid levels. Based on this study, the foliar application T4-Humic acid liquid 15% @ 4.0 ml/l of water might be recommended to improve growth physiology, quality and yield components of Redgram in similar environmental conditions. Further, research is required in diverse plant environments to determine economically feasible application levels of Humic acid while comparing it with other plant growth regulators sources.

Evaluation of Antioxidant Activity of Garden Thyme (Thymus vulgaris L.) Affected by Humic Acid Under Urmia-Iran Condition

The trial aimed to study the effects of different levels of humic acid on the antioxidant activity of garden thyme. The study was conducted at the experimental fields of the Agronomy Department, Faculty of Agriculture, Urmia University, West Azerbaijan, Iran, and used randomized complete block design with four replications. Three different humic acid doses; 200 kg ha−1, 400 kg ha−1 and 600 kg ha−1, and control with no humic acid were the treatments. Total phenolic content, total flavonoid content, DPPH (1,1-diphenyl 2-picryl hydroxyl) radical scavenging activity, nitric oxide radical scavenging activity, and chain-breaking activity were determined. According to the results, the effect of different levels of humic acid in the first harvest on total flavonoid content and nitric oxide radical scavenging was significant whereas, in the second harvest, total phenols content, total flavonoids content, DPPH radical scavenging activity, and chain-breaking activity were significant. The maximum total phenolic content, and nitric oxide radical scavenging activity were obtained in the control treatment. The highest total flavonoid content, DPPH radical scavenging activity, and chain-breaking activity were obtained in the application of 400 kg ha−1 and 600 kg ha−1 humic acid.

Assessing Interactive Response of Humic Acid Amended Media and IBA on the Growth and Propagative Capacity of Fig (Ficus carica L.) Stem Cuttings

This study assessed the interactive effects of humic acid (HA) amended growing media (GM) and indole butyric acid (IBA) on a range of parameters determining growth and propagative capacity of Fig (Ficus carica L., var Black Mission) stem cuttings. Cuttings were treated varying IBA concentration (0, 500, 1000 and 1500 mg/L) and propagated in nine GM consisted of sandy loam and clay soils amended with four levels of HA (0, 2.5, 5.0, 7.5 g/m2) and a mixture of sandy loam and clay soils (1:1 v/v) without HA. Ranking of GM changed across IBA concentrations for the majority of parameters, including plant survivability (PS) indicated significant GMxIBA interaction. PS increased with rising IBA concentration (500-1000 mg/L) under lower levels of HA (2.5-5.0 g/m2) across GM. However, the relative response was better in sandy loam based GM. Based on stepwise multiple linear regression, seven parameters viz., percent bud sprout (PBS), shoot length (SL), shoot diameter (SD), leaf area (LA), leaf chlorophyll content (LCC), root to shoot ratio (R/S) and plant N uptake (NUP) explained most of the variance (R2= 99.8%) in plant survival (PS) and acted as the critical determinants of survivability in Fig propagation via stem cuttings. Strong inter relationships existed among the critical traits, thus creating complex trade-offs affecting the overall propagative capacity of Fig stem cuttings. Our approach could be useful in developing indirect selection criterion determining success rates in propagation via stem cuttings.&#x0D;

Impact of Nitrogen, Zinc and Humic Acid Application on Wheat Growth, Morphological Traits, Yield and Yield Components

To investigate the response of wheat to different levels of nitrogen (N), zinc (Zn) and humic acid (HA), an experiment was conducted at Agronomy Research Farm, the University of Agriculture, Peshawar, during 2014-15. The experiment was laid out in a randomized complete block design having three replications. Three levels of N (80, 120 and 160 kg ha-1), Zn (6, 12 and18 kg ha-1) and HA (5, 10 and 15 kg ha-1) were used. Results showed that N application at the rate of 160 kg ha-1 manifested maximum days to physiological maturity (164 days), productive tillers m-2 (248), spikes m-2 (258), leaf area tiller-1 (113.6 cm2), spike length (10.4 cm), grains spike-1 (52), 1000-grain weight (47.5 g), biological yield (9260 kg ha-1), grain yield (3723 kg ha-1) and harvest index (40%). Zn treated plots at the rate of 12 kg ha-1 showed maximum days to physiological maturity (162 days), productive tillers m-2 (241), spikes m-2 (252), grains spike-1 (51), 1000-grain weight (45.2 g), biological yield (8843 kg ha-1), grain yield (3375 kg ha-1) and harvest index (39 %). Similarly, HA treated plots at the rate of 12 kg ha-1 revealed maximum days to physiological maturity (162 days), productive tillers m-2 (238), spikes m-2(249), spike length (9.7 cm), 1000-grain weight (45.00 g), biological yield (8649 kg ha-1), grain yield (3342 kg ha-1) and harvest index (39%). The combined application of N, Zn, and HA had significantly affected wheat yield and yield components. It was concluded that N at the rate of 160 kg ha-1, Zn 12 kg ha-1 and HA 10 kg ha-1 significantly increased yield and yield components of wheat.

New insights into the cooperative adsorption behavior of Cr(VI) and humic acid in water by powdered activated carbon

Chromium and humic acid often co-exist in wastewater and source waters, and the removal of chromium through sorption by activated carbon may be greatly influenced by humic acid. In this study, we systematically evaluated concurrent adsorption of humic acid (HA) and hexavalent chromium (Cr(VI)) in water by powdered activated carbon (PAC) and further, the effect on conversion to trivalent chromium (Cr(III)). Adsorption of both HA and Cr(VI) was significantly enhanced in the dual adsorbate system as compared to treatments with HA or Cr(VI) alone. The removal of HA increased by 16.0% in the presence of 80 mg/L Cr(VI), while the removal of Cr(VI) similarly increased with increasing levels of HA. However, the promotion effect of HA was found to decrease with increasing pH. With HA at 20 mg/L, removal of Cr(VI) increased from 40.09% to 70.12% at pH 3, which was about twice the increase at pH 10. The cooperative adsorption mechanism was explored using scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), Raman spectroscopy, Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). Comprehensive analysis of spectra suggested that the mutual promotion between HA and Cr(VI) adsorption was attributable to the formation of Cr(VI)-HA and Cr(III)-HA complexes that were readily adsorbed on the PAC surfaces. The higher HA concentrations increased the reduction of Cr(VI) to Cr(III), which was likely due to the electron transfer provided by the functional groups such as -CO, -OH and -COOH in both PAC and HA. At pH 3, 99.1% of Cr adsorbed on the PAC surface was in the form of Cr(III). These findings imply that the interactions between Cr(VI) and HA in the process of water treatment by PAC provides additional and synergistic benefits, leading to a greater removal of chromium.

Response of growth and yield of Sorghum (Sorghum bicolor L.) to different levels of Humic acid and sea- ALgae extract

The experiment was carried out during spring season of 2021 in two locations; first at village of Al-Thulja (10 km) northwest of Mosul, and second at Al-Shuada’a village (35 km) southwest of Mosul, this experiment aimed study of effect of Humic acid, and Seaweed algae on growth and forage yield of Sorghum (Sorghum bicolor L.).This experiment was carried out according to Split-plot in Randomized Complete Block Design (RCBD) with three replications, where the main plot for Seaweed Algae with three levels (0, 2, and 4 ml.L-1) (dissolved in water), while Humic acid with three levels was in sub-plot (0, 6, and 12 kg.ha-1).The most of important results can be summarized as follow: most of growth, and dry forage yield traits at Seaweed Algae (4 ml.L-1) in both locations, were superior of dry forage yield (13 tons.ha-1) at (4 ml.L-1) in second location. Humic acid (12 kg.ha-1) had highest values for all traits at both locations where (12.8, and 12.85 tons.ha-1) for both locations respectively.

INFLUNCE OF CULTIVARS, PLANT GEOMETRY, HUMIC ACID AND THEIR INTERACTIONS ON GROWTH AND YIELD OF NIGER (Guizotia abyssinicia Cass.) CROP

INFLUNCE OF CULTIVARS, PLANT GEOMETRY, HUMIC ACID AND THEIR INTERACTIONS ON GROWTH AND YIELD OF NIGER (Guizotia abyssinicia Cass.) CROP

Available Nutrient Status of Soil as Influenced by Combined Application of Humic Acid and Inorganic Nitrogen

A field experiment was carried out to study the influence of different levels of humic acid (10, 20, 30 kg ha-1) and inorganic N fertilizer viz., 100 % of recommended dose and 75 % of recommended dose on chemical properties of soil under direct sown rice at Agricultural college farm, Bapatla during 2019. The experiment was laid out in RBD with ten treatments replicated thrice with BPT-5204 variety of rice as test crop. Soil samples collected at tillering, panicle initiation and harvest stages of crop were analyzed for chemical properties like available N, P2O5, K2O, Sulphur and cationic micro-nutrients (Fe, Mn, Zn, Cu). Results indicated that increased availability of N, P2O5, K2O, Sulphur and cationic micro-nutrients (Fe, Mn, Zn, Cu) were observed with the treatment T6 involving 100% RDN and HA @ 30 kg ha-1.

Water need and water use efficiency of two plant species in soil-containing and soilless substrates under green roof conditions

Despite the significance of urban landscapes, there are limiting factors like spaces and water resources to expand them across the world. These limitations necessitate the development of water-conserving strategies in vertical infrastructures such as green roofs. One water-conserving strategy is precise irrigation regimes based on the plant species’ water needs. We investigated the water need of Carpobrotus edulis and Aptenia cordifolia under treatments with different soil-containing and soil-less water-absorbing substrate amenders and humic acid applications. The experiment was factorial based on a randomized complete block design with three replications and was conducted from May to September 2020. The first factor was the substrates with different green roof substrate compositions including soil-containing and soilless substrates with varying bentonite percentages. The second factor was humic acid levels (zero, 100, and 200 mg/l), which were applied as fertigation every 15 days during the experiment. Water needs were determined using the lysimetric method. The results showed that despite the soil-containing substrate with bentonite, the soilless substrate alone could not lead to optimal plant growth. The highest water use efficiency and the least evapotranspiration were obtained from the substrate containing 20%Soil +20% leca +20% perlite +20% mineral pumice +20% leaf litter plus 12% w bentonite, combined with A. cordifolia. This plant species showed a better performance compared with C. edulis. During the spring and summer months, the soil-containing substrate with bentonite and A. cordifolia can create a sustainable green roof system by creating better coverage, more water conservation, and a more aesthetic appearance. Based on the results, the application of the highest concentration level of humic acid (200 mg/l) increased the water use efficiency by about 40% after the establishment of the plants. Also, using this level of humic acid reduced the evapotranspiration rate in A. cordifolia up to 10 ml/day and in C. edulis up to 15 ml/day.

Effect of Humic Acid on Growth and Yield Several Genotypes of Rice (Oryza Sativa L.)

A field experiment in the province of Muthanna during the summer season 2014-2015 to study the effect of three levels of humic acid on the growth and yield five genotypes of rice, the experiment carried out using a design Split Plot Design with three replications as occupied the main panels three levels of Humic acid (0, 2 and 4) ml liter−1 while genotypes occupied (IR-60819 and PR-2235 and Mchkab-1 and Jasmine and Amber-33) secondary panels. The results showed that there were significant differences between the humic acid leves, treatment 4 ml liter −1 overtook in a period of flowering (109.88 days), plant height, (99.33 cm) area of flag leaf, (38.11 cm2) number of panicle 373.33 panicle/m2 the number of grains 129.83 grains/panicle and yield grains 4.66 ton/h and there was no significant difference in grain weight, as well as the presence of significant differences between genotypes for all growth traits, as observed superiority of class dormitory -33 moral in the period of flowering, (110.88 days), Mchkab−1 in plant height, (111.34 cm) Yasmin in the flag leaf area, which amounted to 45.00 cm 2, as it gave the class Mchkab-1 highest number of Panicles totaled 400.00 Panicles/m2, and the superiority of product was Jasmine and averaged 145.11 grain/Panicle, and the superiority of genotype RP -2235 average grain weight of 20 mg were given a The interaction (4 × Mchkab−1) higher average plant height was 118.27 cm whereas given the The interaction (0× IR-60819) less than an average of 77.44 cm, either on the flag leaf area has given The interaction (4 × Yasmin) averaged 45.45 cm 2, while given the The interaction (0 × RP-2235) below average for this trait was 30.02 cm 2, and for yield and its components given The interaction (2 × Mchkab−1) the highest average number of Panicles 450.00 Panicle/m 2, while the number of grains in the deltoid has The interaction gave (2 × Yasmin) the highest average number of grains/Panicle totaled 150.00 grain/Panicle while given The interaction (4 × IR-60819) less than an average of 98.66 grain/Panicle, also was given The interaction (2 × Mchkab −1) yield the highest average grain amounted to 5.82 tons/h, while the The interaction gave (0 × IR-60819) less than the average stood at 3.05 tons/ha.

Effects of Irrigation Management and Humic Acid on Yield and Yield Components of Peanut (Arachis hypogaea L.)

Peanut is an oilseed plant, which is rich in seed oil and protein content. The effects of different irrigation methods and humic acid dosages were explored on yield and yield components of peanuts in Astaneh-ye Ashrafiyeh County in Guilan province, Iran, in 2018 and 2019 cropping years. The experiment was laid upon a split-plot design based on a randomized complete block design with three replications in which the main plot was assigned to irrigation treatments including rainfed treatment and irrigation to meet 60%, 80%, and 100% of water requirement, and the sub-plot was assigned to humic acid (HA) at four rates of 0, 3, 6, and 9 L ha-1. The results showed that the highest biological yield (9750 kg ha-1) was obtained from the plants irrigated to meet 80% of their water requirement and applied with 9 L ha-1 HA and the lowest (2453 kg ha-1) was produced under rainfed conditions with no HA applied. Seed yield was 1863 kg ha-1 at the 80% water requirement level and 2067 kg ha-1 at the HA level of 9 L ha-1. Based on the results, it can be recommended to apply 9 L ha-1 HA and supply 80% of the plants’ water requirement as appropriate conditions for the studied region.

Influence of humic acid application on onion growth characteristics under water deficit conditions

In this study, effect of water shortage on onion growth and quality was evaluated under soil humic acid (HA) application. Three levels of irrigation namely: a1; 80%, a2; 70% and a3; 60% of field capacity (FC) were supplied to plants in combination with two levels of HA namely: b1; 0 and b2; 100 mg/kg soil, in a factorial and completely randomized design with four replications. The interaction of irrigation and HA was significant on leaf dry weight, vitamin C, calcium, total chlorophyll and bulb flavonoids, while the onion fresh yield was not affected by treatments. Many plant growth traits showed a reducing trend with deficit irrigation levels. The leaf biomass as well as the leaf concentrations of potassium, calcium and zinc were significantly decreased under highest water deficit treatment (60% FC; a3b1 and a3b2) compared to control (a1b1) treatment. Leaf vitamin C and calcium concentration showed almost a similar response in which their highest levels were observed in a1b2 treatment, while the lowest amounts were recorded under higher water shortage (a3b1), and application of HA (a3b2) significantly increased these traits under higher water shortage. The amounts of bulb flavonoids and phenols were increased by deficit irrigation and application of HA further increased their content under highest deficit irrigation. The results indicate that water deficit particularly at highest level reduced onion plant growth, while soil application of HA significantly increased the growth and quality traits including leaf biomass, vitamin C, and minerals like Ca, as well as bulb flavonoids under water deficit conditions.

Effect of Levels of Humic Acid at Different Times on Improvement of the Growth of Calendula (Calendula officinalis L.) Plant

Calendula (Calendula officinalis L.) is an annual winter plant that belongs to family Asteraceae. It generally used as landscape bedding or ornamental potted plants. The economic and environmental sustainability of ornamental plants production can be improved by environmentally friendly organic substance, such as humic acid (HA). Seedlings of Calendula were sprayed by the organic foliar (HA) fertilizer (0.0, 0.5, 1.0, 1.5, and 2.0 g/L) for one, two, three and four times every 15 days after transplanting. Growth traits, leaf pigment contents, leaf gas exchange, and leaf water potential of C. officinalis were determined. The results showed that plants treated with foliar applications of HA with different levels exhibited plant height, the number of leaves, leaf area, shoot dry mass, and as well as the number of flowers, flowers display time, flower diameter and flower dry mass. shootsThe promoting influences of the foliar application of HA on the growth and development of plants were obvious reflected using the two dose 1.5 and 2.0 g/L at three times. Humic acid enhanced vegetative and flowering traits of the Calendula plant, improved leaf pigments content and both photosynthesis rate and transpiration rate. Therefore, HA gives a good chance to improve the growth of Calendula as a model for ornamental plants production.

بررسی پاسخ گیاه ارزن (Panicum miliaceum) به کاربرد اسید هیومیک، سیلیسیم و میکوریزا در شرایط تنش شور سدیمی آب آبیاری

IntroductionSalinity and sodicity stresses are the major problems in the production of crops under arid and semi-arid regions. Sustainable management by using water and soil resources, under conditions of salinity and sodicity, is considered as a management strategies, also application of mycorrhizal fungi along/or organic matter such as humic acid addition are the major causes in reclamation of the environment and also increases the stability of agro-systems by reducing the use of chemical fertilizers. Among other ways to overcome the negative effects of salinity on the growth and yield of the plant, application of ordinary silicon and silicon nanoparticles have prior importance. This research was conducted to evaluate the effect of humic acid, mycorrhiza and silicon (ordinary and nano) on yield and nutrient content of millet under saline-sodic irrigation water. Materials and methodsA field experiment was conducted as split plot factorial in a randomized complete block design with three replications in summer 2015. The study area is located in Tabas city, South Khorasan province (Iran) with longitude 56o 53' and latitude 33o 34'. The main plots consisted of saline-sodic irrigation water (S) at two levels (S1= EC: 2.1 dSm-1, SAR:11.5 and S2= EC: 5.04 dSm-1, SAR: 20.8) and a combination of sub factors including three treatments of silicon salts (SI): (control (Si0), silicon nanoparticles, 10KgSiha-1 (NSi) and ordinary silicon (by using sodium silicate salt) 10KgSiha-1 (Si)) and three levels of mycorrhiza and Humic acid (MH): (control (MH0), inoculation with Glomus mosseae mycorrhizal fungi (M) and humic acid 10Kgha-1 (H)) as The factorial was placed in the main plots. Results and discussion The results showed that increasing salinity-sodicity of irrigation water decreased grain yield, straw yield, number of panicles per square meter and plant height and its effect on 1000 seed weight and grain number per spike were not significant. Increasing salinity-sodicity of irrigation water decreased the grain yield by reducing the number of panicles per square meter, reduction of the straw yield due to its negative impact in plant height. The application of silicon nanoparticles treatment increased the grain yield compared to non-silicon treatment, but ordinary silicon (sodium silicate) had no effect. Mycorrhizal inoculation increased grain yield, straw yield and panicle per square meter and application of humic acid also increased grain yield, number of panicles per square meter. Mean grain yield at S1 level increased with the use of humic acid and mycorrhiza and in S2 level, mean grain yield increased only with the use of humic acid. Saline-Sodic irrigation water reduced the concentrations of nitrogen, phosphorus, potassium and K/Na ratio, and increased sodium concentration in millet. Application of silicon had no significant effect on nitrogen, phosphorus, potassium, sodium and K/Na ratio in the plant, but mycorrhiza and humic acid increased plant phosphorus and K/Na ratio and decreased sodium content of the plant. ConclusionsAccording to our results, it can be concluded that the use of silicon nanoparticles in comparison with ordinary silicon (sodium silicate) could increase the yield of millet. Also the application of humic acid or mycorrhiza can be improved the yield of millet by increasing the amount of phosphorus and K/Na ratio and decreasing sodium content in millet and thus the enhancement of resistance of the plant and the reduction of the effects of salinity-sodicity of water irrigation, and in this regard, the effect of humic acid was much superior to mycorrhiza impact.

The Effect of Humic Acid and Potassium Applications on The Yield and Yield Components in Chickpea (Cicer arietinum L.)

The study was conducted to determine effects of different levels of humic acid and potassium on the yield and some yield components in chickpea in 2017 in Mardin city. The experiment was laid out in a factorial randomised block design with three replications. The doses were used potassium (0, 10 and 20 kg da-1) and humic acid (0, 30 and 60 kg da-1) in this study. In the study were investigated the plant height, first pod height, branch number per plant, pod, seed number and per plant, biological yield, seed yield per unit, harvest index, 100-seed weight, protein ratio and potassium content in seed. The results of the study indicated that humic acid and potassium applications increased significantly the seed yield and yield components. The highest seed yield was obtained from 20 kg phosphorus da-1 + 60 kg humic acid da-1 application as 286.9 kg da-1.

EFFECT OF HUMIC ACID AND PHOSPHOROUS ON GROWTH AND YIELD OF ONIONS IRRIGATION WITH DIFFERENT SALINE WATER

The study was carried out at the College of Agriculture University of Anbar during the spring season of 2018, the study conducted by using water for irrigation with different electrical conductivity (1.1, 3.00, 5.00, and 7.00 Decimeters M-1) which marked as W1, W2, W3, and W4. This study has included three experiments. The field experiment used water for irrigation with different electrical conductivity (1.1, 3.00, 5.00, and 7.00 Decimeters M-1) and three levels of humic acids were used: (0, 20 and 40 kg.H-1) H0, H1 and H2. Also, there are three levels of mono superphosphate fertilizer were used: P0, P1, and P2 (0, 100, and 150 kg. E-1). to estimate of heterosis on some growth properties of onion yield. The results showed decrease for plant's height when the salinity of irrigation water increased. while the leaf’s area, and the stem diameter increased by decreasing salinity at the level 7 decimeters M-1, the leaf's area, and the stem diameter increased increasing by adding humic acid levels and phosphate fertilizer levels. The results showed decrease in the total yield, by increase in the salinity of irrigation water from 1.1 to 7 decimeters M-1, while the total yield was increased by adding humic acid and phosphate fertilizer levels.

Effect of Humic Acid on Tolerance indexes of Barley plant to Cadmium Toxicity

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; This study was carried out to evaluate the effect of different levels of Humic acid (0, 400, 800 ppm) on tolerance index of barley plant to different levels (0, 25, 50 and 100 ppm) of Cadmium. The experiment was designed according factorial completely randomized design with three replications. The results revealed that the combination effect of Humic acid and Cadmium significantly increased the total dry weight, number of spikes and dry weight of straw, as well as in total dry weight of plant, cadmium tolerance was found by treatments HA0CD50, HA0CD10, HA400CD0, HA400CD25, HA400CD100, HA800CD50, HA800CD100. Cadmium significantly decreased the relative chlorophyll production rate (RCPR) of Barley plant,