Commercial Humates Research Articles

The influence of humates produced by “Shubarkol Komir” JSC on the germination of seed material of various vegetable crops

The biological activity of humid substances is manifested in increasing the resistance of plants to unfavorable factors and stimulating their metabolic processes, which has a positive effect on the growth characteristics of both seed material and the vegetative part of the whole plant. The article examines the influence of humates produced by “Shubarkol Komir” JSC during pre-sowing soaking on the germination of seed material of various cultivated plants, and assessed their antifungal activity. Commercial humates “Ideal”, “Gumate 7+”, and “Biomaster” humates were used as comparison preparations. In the experiments, seed material of the following crops and varieties was used: tomato, Siberian Yabloko variety; eggplant, Caviar Paradise variety; sweet pepper, D'Artagnan variety; water cress, Abundant-leaved variety; radish, grade “5+”; nut. For tomato and sweet pepper, the best content of humates in the solution for soaking seed material wa s 0.5%, for eggplant, watercress, radish and chickpeas – 0.1%. The effectiveness and antifungal activity of “Shubarkol Komir” humate is not inferior to commercial drugs used as reference drugs.

Is application of commercial potassium humates beneficial to soil and wheat?

Commercial humates manufactured from oxidised lignites are often recommended to improve soil condition and crop growth. The benefits ascribed to these products are questioned, since they differ from humates that exist naturally in soils. Growth chamber, glasshouse and field experiments were conducted at facilities of the University of the Free State to quantify the influence of three potassium (K)-humate products on irrigated wheat growth and development, in loamy sand, sandy clay loam and clay loam soils. The humate products were applied to the soils at rates prescribed by their promoters. Results showed that the K humates were not beneficial for wheat growth and development as indicated by above-ground and subsoil plant parameters at tillering, stem elongation and maturity. However, the application of the K-humates caused higher bacteria and fungi counts in soil, which differed between the products applied. Despite the higher counts of bacteria and fungi in soil, grain yields were not affected, probably because no improvement in soil chemical properties were observed. Therefore, the application of K-humate products is not necessarily economically viable since they are relatively expensive. However, foliar applications of K humates may have stimulatory effects on wheat growth and development, resulting in better grain yields that could justify the higher production cost. An investigation into this aspect is suggested.

Effect of Soil Organic Matter and Humates on Adsorption and Desorption Chemistry of Iodide in an Aridisol

The translocation of iodine (I) from soil to food chain is largely determined by its adsorption/desorption reaction in soils. In this study, the effects of commercial humates (HA) applied on an Aridisol and indigenous soil organic matter (SOM) on the adsorption and desorption of iodide were investigated. For this reason, 1% and 3% HA (w/w) were incorporated into the whole soil (WS) and organic matter free (OMF) soil samples. Then soil samples were equilibrated with 0, 2, 4, 6, 8 and 10 mg L-1 iodide solution prepared in 0.01 molar CaCl2 for 40 h. The sorption data were better described by Langmuir isotherm (R2= 0.938) than Freundlich isotherm (R2= 0.763). The Langmuir sorption maximum of WS was 19.8 mg kg-1. Freundlich isotherm parameters were n= 0.89 and Kf= 2.165. Sorption maximum of OMF soil significantly increased up to 35.5 mg kg-1. HA applications reduced iodide sorption maximum of both WS and organic OMF soil samples. Desorption rate of the WS ranged between 0-15.3% whereas it decreased 0-0.65% upon removal OM. HA treatments, in general, reduced the desorption rates. However, increasing HA application resulted in higher desorption ratio in both WS and OMF soils. Consequently, either SOM or HA has preeminent role in the adsorption-desorption chemistry in soils.

A simple technique for assessing the cuticular diffusion of humic acid biostimulants

BackgroundExperimental determination of the extent and rate of transport of liquid humates supplied to plants is critical in testing physiological effects of such biostimulants which are often supplied as foliar sprays. Therefore, an original experimental method for the qualitative investigation and quantitative description of the penetration of humates through plant cuticles is proposed, tested, and evaluated.ResultsThe proposed method involves the isolation of model plant leaf cuticles and the subsequent in vitro evaluation of cuticular humate transport. The employed novel methodology is based on a simple diffusion couple arrangement involving continuous spectrophotometric determination of the amount of penetrated humate in a hydrogel diffusion medium. Prunus laurocerasus leaf cuticles were isolated by chemical and enzymatic treatment and the rate of cuticular penetration of a commercial humate (lignohumate) was estimated over time in quantitative and qualitative terms. Different rates of lignohumate transport were determined for abaxial and adaxial leaf cuticles also in relation to the different cuticular extraction methods tested.ConclusionsThe proposed methodology represents a simple and cheap experimental tool for the study on the trans-cuticular penetration of humic-based biostimulants.

Commercial Humates in Agriculture: Real Substance or Smoke and Mirrors?

Soil humic substances (HS) are known to be beneficial for soils and plants, and most published studies of HS and humates, usually conducted under controlled conditions, show benefits. However, the value of commercial humate application in the field is less certain. This review attempts to answer the question: How effective are commercial humates in the field? Commercial humates, especially K humate, are used widely in agriculture today as “soil conditioners”. A wide range of benefits is claimed, including growth of beneficial soil microbes; deactivation of toxic metals; improvements in soil structure including water retention capacity, enhanced nutrient and micronutrient uptake and photosynthesis; resistance to abiotic stress, including salinity; and increased growth, yield and product quality. Despite this, there is a surprising lack of solid evidence for their on-farm effectiveness and findings are often inconsistent. The industry relies largely on anecdotal case studies to promote humates, which are often applied at unrealistically low levels. It is recommended that products should be well characterised, physically and chemically, and that careful field studies be conducted on foliar humate application and pelletised humates at realistic rates, targeted to the seedling rhizosphere, for a variety of crops in a range of soils, including low C sandy and saline soils.

Use of biochar-compost to improve properties and productivity of the degraded coastal soil in the Yellow River Delta, China

Nutrient deficiency and salt stress (sodium, Na+) strongly limited the productivity of the degraded coastal soils in the Yellow River Delta. Biochar-based functional materials have been considered as a promising amendment to solving the problem of global soil security (e.g., erosion, fertility loss, acidification, and salinization). Therefore, this study aimed to explore the potential of using a biochar-compost amendment (BCA) to improve the coastal soil properties and productivity. The BCA was produced from composting of biochar and additives including seafood shell powder, peanut shell, commercial humate, and inorganic nutrients. Two halophytes, sesbania (Sesbania canabina (Retz.) Pers) and seashore mallow (Kosteletzkya virginica), were chosen as the tested plants in a 52-day pot experiment. BCA was added as the rates of 0, 1.5, 5, and 10 % (w/w). At the end of the incubation, the shoot height, biomass, and root morphological parameters including length, tips, and surface area were measured, as well as the properties (e.g., soil organic matter (SOM) content and cation exchange capacity (CEC)) of the rhizosphere and non-rhizosphere soils. The BCA application at 1.5 % enhanced the growth of sesbania and seashore mallow and increased their total biomass by 309 and 70.8 %, respectively, while significantly inhibited both the halophyte growths at 10 %. Similarly, both the halophyte root morphologies (e.g., length and tips) significantly increased by BCA addition at 1.5 %. The promoting growth of the both halophytes could be resulted from the improvement of soil properties such as the increased SOM and CEC, the decreased amount of the exchangeable sodium (Ex-Na) and exchangeable sodium percentage (ESP), and the rhizosphere effect (e.g., decreased soil pH). The higher rate of BCA addition (e.g., 10 %) sharply increased soil salinity, responsible for the inhibition of both the halophyte growths. Although BCA addition may directly supply much nitrogen (N) for the soils, N bioavailability for both halophytes was not largely improved. The short-term laboratory pot experiments revealed that producing the biochar-compost with desired properties (e.g., BCA) could be a feasible alternative to remediate the degraded coastal soil in the Yellow River Delta. Moreover, the addition of BCA should be kept at an optimal level, which may produce expected positive results. Our results will be helpful for supporting the strategy of designing right biochar-compost for the right soil.

Investigation of the effect of humic acids using luminescent bacteria test

The effect of commercial humates and preparations of humic substances isolated from different sources on microbial cells was investigated with the luminescent bacteria test. The saturated solutions of humic substances inhibited luminescence of the test objects, and, at the same time, these preparations decreased the detrimental effect of Cu2+ on live cells.

Modeling priming effects on microbial consumption of dissolved organic carbon in rivers

AbstractRivers receive and process large quantities of terrestrial dissolved organic carbon (DOC). Biologically available (unstable) DOC leached from primary producers may stimulate (i.e., prime) the consumption of more stable terrestrially derived DOC by heterotrophic microbes. We measured microbial DOC consumption (i.e., decay rates) from contrasting C sources in 10 rivers in the western and Midwestern United States using short‐term bioassays of river water, soil and algal leachates, glucose, and commercial humate. We added inorganic nutrients (ammonium and phosphorus) to a subset of bioassays. We also amended a subset of river, soil, and commercial humate bioassays with glucose or algal leachates to test the hypothesis that unstable DOC primes consumption of more stable DOC. We used prior measurements of source‐specific DOC bioavailability, linked with a Bayesian process model, to estimate means and posterior probability distributions for source‐specific DOC decay rates in multisource bioassays. Modeled priming effects ranged from a −130 to +370% change in more stable DOC decay when incubated with unstable DOC. Glucose increased modeled river DOC decay by an average of 87% among all rivers. Glucose and algal leachates increased soil leachate and commercial humate decay by an average of 25% above background rates. Inorganic nutrient additions did not have consistent effects on DOC decay, likely because most of the study rivers had high ambient background nutrients. Our results demonstrate that the priming effect can augment DOC decay in rivers. In addition, Bayesian models can be used to estimate mechanisms driving aquatic ecosystem processes that are difficult to measure directly.

Humic preparations and the assessment of their biological activity for certification purposes

The diversity of responses of test organisms (higher plants, microalgae, protozoa, crustaceans, bacteria, and mammal cell cultures in vitro) to the action of humates produced industrially from different raw materials was discussed in relation to the urgent problem of the certification of structural and functional properties of commercial humates. It was proposed to include higher plants (for assessing the effect of stimulation) and a set of biotests using test organisms of different trophic levels (for determining toxic concentrations) in the program of assessing the biological activity of humic preparations by laboratory testing methods.

Earthworms as modifiers of the structure and biological activity of humic acids

Passage of humic acids (HAs) through the digestive tract of the earthworm, Eiseniafetida andrei, resulted in a decrease in molecular masses of the HAs. The effect of earthworm-modified HAs on individual bacteria and on bacterial communities as a whole is different from the effect of native HAs. Modified HA probably induces and regulates microbial successions in soils and composts in a different manner than the native HA, suppressing or stimulating different groups of microorganisms. These results may explain why the positive effects of commercial humates in real soil ecosystems, unlike model communities, attenuate rapidly.

Influence of Humic Products on Soil Health and Potato Production

Since 1900, soil organic matter (SOM) in farmlands worldwide has declined drastically as a result of carbon turnover and cropping systems. Over the past 17 years, research trials were established to evaluate the efficacy of different commercial humates products on potato production. Data from humic acid (HA) trials showed that different cropping systems responded differently to different products in relation to yield and quality. Important qualifying factors included: source; concentration; processing; chelating or complexing capacity of the humic acid products; functional groups (Carboxyl; Phenol; Hydroxyl; Ketone; Ester; Ether; Amine), rotation and soil quality factors; consistency of the product in enhancing yield and quality of potato crops; mineralization effect; and influence on fertilizer use efficiency. Properties of humic substances, major constituents of soil organic matter, include chelation, mineralization, buffer effect, clay mineral-organic interaction, and cation exchange. Humates increase phosphorus availability by complexing ions into stable compounds, allowing the phosphorus ion to remain exchangeable for plants’ uptake. Collectively, the consistent use of good quality products in our replicated research plots in different years resulted in a yield increase from 11.4% to the maximum of 22.3%. Over the past decade, there has been a major increase in the quality of research and development of organic and humic acid products by some well-established manufacturers. Our experimentations with these commercial products showed an increase in the yield and quality of crops.

Gro-Mate Soil Amendment Improves Growth of Greenhouse-grown `Chardonnay' Grapevines

Own-rooted, glasshouse-grown `Chardonnay' vines (Vitis vinifera L.) were planted in a sand medium to which was added one of five levels of granular Gro-Mate (GM), a commercial humate (0, 8, 16, 32, 64 g/pot; 0 to 35 g a.i./pot). Two other treatments consisted of weekly (1× W) or twice-weekly (2× W) applications of liquid GM, whose cumulative addition over the 28 weeks of the experiment totaled 6.7 and 13.4 g a.i., respectively. Shoot length responded to increasing level of GM in a predominantly cubic fashion, with 32 g/pot resulting in the longest shoots. Fresh and dry weights of leaves, shoots, and roots, as well as leaf count and area, exhibited increasing linear or quadratic trends in response to increased level of granular GM. GM increased soil organic matter, K, Ca, Mg, Fe, Mn, Cu, Na, and S and also increased petiole Fe and lamina P, K, and Fe. Liquid treatment resulted in lower soil pH, organic matter, bulk density, and Fe and higher soil conductivity, NO3, P, K, Mg, Cu, Zn, Na, and S than the granular treatments, as well as higher petiole and lamina N and K, lower petiole and lamina P, and lower petiole Zn. Compared to the 1× W treatment, the 2× W produced lower soil bulk density and higher P, lower lamina K, Mn, and Fe; lower petiole Mn; and higher petiole Cu. Plant tissues contained extremely high levels of Mn irrespective of treatment, whereas liquid treatments resulted in high soil NO3 levels. Although liquid GM cannot be recommended for young grapevines under an application regime such as described here, preplant applications of granular GM may have potential for improving growth of young vines in coarse-textured soils. High granular or excessive liquid applications may result in leaf necrosis and retarded growth.

Chemical characteristics and microbial degradation of humate

Abstract Humates are often used in agriculture as a source of organic matter. This study was conducted to characterize a commercial humate and to evaluate its chemical and decomposition characteristics. Characterization methods included fractionization of humic and fulvic acids of the humate, based on their alkali/acid insolubility; elemental analysis; acidic functional group analysis; and E4/E6 ratio determinations. The humate consisted of the following: 58% organic matter, 32% ash, and 10% moisture. Humic fraction was mostly humic acid (76%), with some fulvic acid (18%). Organic elemental composition [59% carbon (C), 5% hydrogen (H), and 36% oxygen (O)] also suggests a humic‐acid nature. Inorganic elemental content of this humate, which was primarily aluminum (Al) [4.9%] and iron (Fe) [0.46%], reflects its spodic origin. Much of the Al present, however, results from the flocculant (alum) used at the mining site to precipitate the humate. The relatively low total acidity of this humate (250 cmol/kg) suggests the blockage of some of its functional groups by Al, Fe, and associated clay minerals. After purification, total acidity increased to 510 cmol/kg and acidity associated with carboxyl groups increased to 280 cmol/kg. Results of E4/E6 determinations for the humate (2.5) and the humic‐acid fraction (4.8) also suggested that the organic fraction was predominately humic acid. Decomposition of the humate was estimated by measuring the quantity of carbon dioxide (CO2) evolved during a four‐week incubation. Results suggested a relative resistance to microbial degradation. However, results also suggested the presence of some readily decomposable C compounds associated with humate. Agricultural use of this humate reguires some modifications to produce a more reactive material. This may include a change of flocculant and a lowering of its ash content.

The significance of solid‐state 13C NMR spectroscopy of whole soil in the characterization of humic matter

Abstract Differences in characteristics of humic matter were investigated by solid‐state CP/MAS 13C NMR spectroscopy of whole (nontreated) materials and their extracted humic fractions. Samples used in the analysis were lignite, a commercial humate AG, and the Bh horizons of a Mascotte and a Lawnwood soil. Humic fractions were extracted by the 0.1 M NaOH or Na4P2O7 (pH 9.8) method. The humic (HA) and fulvic acid (FA) obtained were weighed and analysed for total acidity, carboxyl and phenolic‐OH group contents. Whole lignite, humate AG and soil samples, and the HA and FA fractions were analyzed by solid state CP MAS 13C NMR and infrared spectroscopy. Carbon, H, and N contents were determined by chemical analysis. NMR spectra of the combined HA+FA extracts resembled the spectra of the whole materials. No additional signals were detected, indicating that alien compounds were not produced during the extraction. The best spectra were obtained with HA samples produced by the NaOH method. These spectra closely r...

The geochemical nature and agricultural importance of commercial humic matter

The use of commercial humates in agriculture has been received with mixed reactions. Differences in origin between commercial humates and soil humic acids together with a lack of scientific data on the former are perhaps contributing to the controversy. Therefore, this investigation was conducted to determine the geochemical characteristics and effect on plant growth of humic acid (HA) and fulvic acid (FA) isolated from selected commercial humates derived from lignite and non-lignite deposits. Analysis were performed for C, H, N, carbohydrate, aromatic and carboxyl group contents. Spectral characteristics were determined by 13C-NMR and infrared (IR) spectroscopy, whereas effect on plant growth was studied in the greenhouse with corn ( Zea mays L.) plants growing in the presence of commercial humates. The commercial humates were composed mostly of HA, and only very small amounts of FA were extracted. The HA fractions from the commercial humates were similar in C and H contents, but HA from lignite humate was higher in N content than HA isolated from non-lignite humate. Lignite-HA was also characterized by a higher carbohydrate content that non-lignite HA. The latter was more aromatic in nature. The IR spectra supported the presence of higher aromatic contents in HA from non-lignite than that from lignite deposits. Commercial humates were comparable with soil HA in their effect on increasing the growth of corn plants. It can be concluded, that the data suggested that HA from lignite deposits resembled HA in Mollisols, whereas HA from the non-lignite deposits was more related to HA from the Bh horizon of Spodosols.

Detection and quantitation of trace levels of low molecular weight halocarbons (LMHs) associated with commercial sodium humate

Examination of vapor above commercial sodium humate and above 10wt% aqueous humate solution by gas chromatography (GC) revealed the presence of chloroform and trichloroethylene. Further examination of the aqueous humate by the purge and trap procedure confirmed the association of chloroform and trichloroethylene with the humate. GC/mass spectrometry analyses of methylene chloride extract of the humate established the association of LMHs with the humate. Improved headspace capillary GC technique showed that the humate contained not only chloroform, trichloroethylene but several other LMHs in the range 190 to 4000ng·kg‐1.

Commercial humates for agriculture and the fertilizer industry

The humate content of soils must be maintained for optimum productivity. Skilled agriculturists are aware of this and accomplish it by indirect and costly methods. The same can be achieved through the use of humate concentrates, which are salts of the humic acids obtainable from natural sources, that can be added directly to soils along with regular commercial fertilizers.