Biofertilizer Production Research Articles

Beyond Sugar and Ethanol Production: Value Generation Opportunities Through Sugarcane Residues

Sugarcane is the most produced agricultural commodity in tropical and subtropical regions, where it is primarily used for the production of sugar and ethanol. The latter is mostly used to produce alcoholic beverages as well as low carbon biofuel. Despite well-established production chains, their respective residues and by-products present unexploited potentials for further product portfolio diversification. These fully or partially untapped product streams are a) sugarcane trash or straw that usually remain on the fields after mechanized harvest, b) ashes derived from bagasse combustion in cogeneration plants, c) filter cake from clarification of the sugarcane juice, d) vinasse which is the liquid residue after distillation of ethanol, and e) biogenic CO2 emitted during bagasse combustion and ethanol fermentation. The development of innovative cascading processes using these residual biomass fractions could significantly reduce final disposal costs, improve the energy output, reduce greenhouse gas emissions, and extend the product portfolio of sugarcane mills. This study reviews not only the state-of-the-art sugarcane biorefinery concepts, but also proposes innovative ways for further valorizing residual biomass. This study is therefore structured in four main areas, namely: i) Cascading use of organic residues for carboxylates, bioplastic, and bio-fertilizer production, ii) recovery of unexploited organic residues via anaerobic digestion to produce biogas, iii) valorization of biogenic CO2 sources, and iv) recovery of silicon from bagasse ashes.

Selected Rhizosphere Bacteria Help Tomato Plants Cope with Combined Phosphorus and Salt Stresses.

Plants are often challenged by multiple abiotic stresses simultaneously. The inoculation of beneficial bacteria is known to enhance plant growth under these stresses, such as phosphorus starvation or salt stress. Here, for the first time, we assessed the efficiency of selected beneficial bacterial strains in improving tomato plant growth to better cope with double stresses in salty and P-deficient soil conditions. Six strains of Arthrobacter and Bacillus with different reservoirs of plant growth-promoting traits were tested in vitro for their abilities to tolerate 2–16% (w/v) NaCl concentrations, and shown to retain their motility and phosphate-solubilizing capacity under salt stress conditions. Whether these selected bacteria promote tomato plant growth under combined P and salt stresses was investigated in greenhouse experiments. Bacterial isolates from Cameroonian soils mobilized P from different phosphate sources in shaking culture under both non-saline and saline conditions. They also enhanced plant growth in P-deficient and salt-affected soils by 47–115%, and their PGP effect was even increased in higher salt stress conditions. The results provide valuable information for prospective production of effective bio-fertilizers based on the combined application of local rock phosphate and halotolerant phosphate-solubilizing bacteria. This constitutes a promising strategy to improve plant growth in P-deficient and salt-affected soils.

Food Processing Industry Waste and Circular Economy

The continuous rise in world human population increases the demand for food supply thereby increasing food wastage throughout the supply chain which results in environmental pollution and scarcity of natural resources. In addition, food processing industries produce huge quantity of inedible food waste. Land filling and incineration are not the promising approaches of food waste management system for environmental sustainability and economic viability. Recycle and reuse are the major principles of circular economy which focus on the energy and resource recovery from food waste for sustainable environment. Food wastes are mostly rich in organic matters such as carbohydrates, proteins and lipids which can be used as a feed stock for production and/or recovery of bio fertilizers, biofuels, bio gas, valuable bioactive compounds, natural nutrients and industrial enzymes by adapting suitable technologies including composting, anaerobic digestion, and fermentation. In addition, an integrated biological approach for recovery of energy and resources from food waste with the concept of zero solid discharge is found to be economically viable. This review highlights the technological advances in management of food waste including processing methods and product recovery.

English

Indole-3-acetic acid (IAA) is an important plant growth regulator. As the very first endeavor, the study is aimed at extracting and quantifying IAA from seedlings of Bambusa tulda and evaluating its bioactivity. The extraction of IAA was performed in organic solvent followed by sample evaporation and TLC with a mobile phase composed of chloroform, methanol and formic acid (77:22:1 v/v) in isocratic mode. The extract obtained from preparatory TLC was subjected to HPLC with acetic acid and methanol (75:25 v/v) as the mobile phase in isocratic mode at a flow rate of 0.8 ml/min and operation pressure of 54 MPa at 30°C, and detection was monitored at 280 nm. Bioassay of the extracted IAA was carried out in Abelmoschus esculentus seedlings. The similar Rf value (0.412) of the extract during TLC analysis and similar peak of HPLC chromatogram with retention time 28.71 min to that of standard IAA indicated the presence of IAA in B. tulda seedling extract. The extracted IAA was quantified to be 10.28 µg/ml. In bioassay experiment, the extracted IAA significantly enhanced root length, root fresh weight, root dry weight, shoot length, shoot fresh weight, shoot dry weight and significant increase of total chlorophyll and protein in A. esculentus leaves. Therefore, B. tulda seedlings could be a potential source of IAA, and it can be utilized for production of bio-fertilizer at a commercial scale. Key words: Abelmoschus esculentus, Bamboo, High performance liquid chromatography, indole-3 acetic acid.

Quorum Sensing System Affects the Plant Growth Promotion Traits of Serratia fonticola GS2.

Quorum sensing (QS) enables bacteria to organize gene expression programs, thereby coordinating collective behaviors. It involves the production, release, and population-wide detection of extracellular signaling molecules. The cellular processes regulated by QS in bacteria are diverse and may be used in mutualistic coordination or in response to changing environmental conditions. Here, we focused on the influence of the QS-dependent genes of our model bacterial strain Serratia fonticola GS2 on potential plant growth promoting (PGP) activities including indole-3-acetic acid (IAA) production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, and biofilm formation. Based on genomic and phenotypic experimental data we identified and investigated the function of QS genes in the genome of the model strain. Our gene deletion study confirmed the biological functionality of the QS auto-inducer (gloI) and receptor (gloR) on potential PGP activities of GS2. A transcriptomic approach was also undertaken to understand the role of QS genes in regulation of genes primarily involved in PGP activities (IAA, ACC deaminase activity, and biofilm formation). Both transcriptomic and phenotypic data revealed that the QS-deletion mutants had considerably less PGP activities, as compared to the wild type. In addition, in vivo plant experiments showed that plants treated with GS2 had significantly higher growth rates than plants treated with the QS-deletion mutants. Overall, our results showed how QS-dependent genes regulate the potential PGP activities of GS2. This information may be helpful in understanding the relationship between QS-dependent genes and the PGP activity of bacteria, which aid in the production of practical bio-fertilizers for plant growth promotion.

Use of Spent Mushroom Substrate as an Inoculant Carrier and an Organic Fertilizer and Their Impacts on Roselle Growth (Hibiscus sabdariffa L.) and Soil Quality

The potential of using spent mushroom substrate (SMS) as inoculant carrier and organic amendment on the growth of Hibiscus sabdariffa was evaluated. SMS, peat and vermiculite were mixed with plant growth promoting bacteria (PGPB) isolate Bacillus amyloliquefaciens. Different treatments were applied in the cultivation of H. sabdariffa. We found that application of NPK fertilizer, SMS based inoculant, and peat based inoculant significantly promoted plant growth and chlorophyll content compared to other treatments. SMS based inoculant was the best treatment for increasing biomass and chlorophyll content, followed by NPK fertilizer. In addition, application of SMS inoculant or only SMS as soil amendment showed a significant improvement in soil properties including soil NPK, organic matter, soil PGPB and soil enzyme (i.e. soil fluorescein diacetate and dehydrogenase) as well as peat inoculant application. Our results suggested that SMS could be considered as an alternative low-cost, potential carrier in biofertilizer production or soil amendment for providing soil nutrients and recovering soil fertility in farming.

Day and blue light modify growth, cell physiology and indole-3-acetic acid production of Azospirillum brasilense Az39 under planktonic growth conditions.

In this work, we evaluated the effects of light on growth, cell physiology and stress response of Azospirillum brasilense Az39, a non-photosynthetic rhizobacteria, under planktonic growth conditions. Exponential cultures of Az39 were exposed to blue (BL), red (RL) and daylight (DL) or maintained in darkness for 24, 48 and 72h. The biomass production and indole 3-acetic acid (IAA) biosynthesis increased by exposition to DL. Conversely, BL decreased IAA concentration through a direct effect on the molecule. The DL increased superoxide dismutase activity, hydrogen peroxide and thiobarbituric acid reactive substances levels, but the last one was also increased by BL. Both DL and BL increased cell aggregation but only BL increased biofilm formation. We demonstrated that both BL and DL are stress effectors for A. brasilense Az39 under planktonic growth conditions. The DL increased biomass production, IAA biosynthesis and bacterial response to stress, whereas BL induced cell aggregation and biofilms formation, but decreased the IAA concentration by photooxidation. Blue light and DL changes growth capacity, cell physiology and plant growth promotion ability of A. brasilense Az39 and these changes could be considered to improve the production and functionality of biofertilizers.

Enriched biogas and biofertilizer production from Eichhornia weed biomass in cow dung biochar-amended anaerobic digestion system

The effect of cow dung biochar on water hyacinth anaerobic digestion with control setup (without biochar (T0) was investigated using a batch scale setup (at 35 °C). Biochar was applied in three doses (v/v) 0.5% (T0.5), 1% (T1), and 1.5% (T1.5) in anaerobic digestion setups and daily and cumulative biogas formation was recorded in all setups. Results revealed that biochar addition reduced the lag phase from 3 d to 1 d but extended in a higher dose (1.5%). The cumulative biogas production was fund to be 2721 mL in T1 followed by, 2388 mL (T0.5), 1940 mL (T1.5), and 1153 mL (T0) (p<0.001 for all) by the end of 35 days of the AD process. The maximum biogas production improved by 40.6–57.6%, in biochar setups than T0. Spent slurry was analyzed for its possible use as biomanure for plant production and results revealed a considerable amount (g kg−1) of total nitrogen (14.07–16.69), total phosphorous (15.76–17.8), total potassium (21.56–24.12) in spent slurry from biochar-amended setups. Carbon-to-nitrogen ratio (14.2–19.6), NH4 +/NO3-N (<0.16 g Kg−1) ratio, and germination index of spent slurry was also in the acceptable limit as decided for biomanure, indicating its possible utility in plant production. Biochar addition (up to 1%) improves the biomethane contents (4.4–11%) in biogas and nutritional value of spent slurry. This study indicates that weed Eichhornia biomass could be managed effectively by anaerobic digestion for methane-rich biogas and biofertilizer production simultaneously under the circular economy model.

Composting of byproducts from the orange (&lt;i&gt;Citrus sinensis&lt;/i&gt; (L.) Osbeck) and sugarcane (&lt;i&gt;Saccharum&lt;/i&gt; spp. hybrids) agroindustries

There is a global problem involving the generation, management, disposal, and treatment of agro-industrial waste, since it requires technologies for its transformation into the sustainable production of food, fodder, biofuels, fibers, bioproducts, and biofertilizers. The citrus and sugarcane agroindustries generate waste or byproducts that require a special treatment to be reused. Sugarcane byproducts already have an established but unsustainable use. In the case of citrus fruits, 50-60% of the organic waste has an acidic pH (3-4), 95% organic matter, and 80-90% moisture. The objective of this research was to evaluate and model the pile composting method applied to byproducts of the orange and sugarcane agroindustries to obtain compost with competitive physicochemical parameters for use as a soil improver. The pile was designed with a pyramidal rectangular arrangement, and 9 points were established for temperature sampling in three different sections during composting. An average of 55 °C and a pH of 9,1 were obtained at the end of the process. Compared to the regional control, the C/N ratio (27,5), organic matter (65,5%), and macro- and microelements show improved characteristics for use in food production in agroecological agriculture.

Pseudomonas sp. TK35-L enhances tobacco root development and growth by inducing HRGPnt3 expression in plant lateral root formation

Rhizosphere colonization is a key requirement for the application of plant growth-promoting rhizobacteria (PGPR) as a biofertilizer. Signaling molecules are often exchanged between PGPR and plants, and genes in plants may respond to the action of PGPR. Here, the luciferase luxAB gene was electrotransformed into Pseudomonas sp. strain TK35, a PGPR with an affinity for tobacco, and the labelled TK35 (TK35-L) was used to monitor colonization dynamics in the tobacco rhizosphere and evaluate the effects of colonization on tobacco growth and root development. The transcript levels of the hydroxyproline-rich glycoprotein HRGPnt3 gene, a lateral root induction indicator, in tobacco roots were examined by qPCR. The results showed that TK35-L could survive for long periods in the tobacco rhizosphere and colonize new spaces in the tobacco rhizosphere following tobacco root extension, exhibiting significant increases in root development, seedling growth and potassium accumulation in tobacco plants. The upregulation of HRGPnt3 transcription in the inoculated tobacco suggested that TK35-L can promote tobacco root development by upregulating the transcript levels of the HRGPnt3 gene, which promotes tobacco seedling growth. These findings lay a foundation for future studies on the molecular mechanism underlying the plant growth-promoting activities of PGPR. Furthermore, this work provided an ideal potential strain for biofertilizer production.

Extraction of Keratin from Human hair with Production of Biofertilizer from Waste Liquid of Hair Extraction and its Efficient Application on Growth Yield of Abelmoschus esculentus L

Extraction of Keratin from Human hair with Production of Biofertilizer from Waste Liquid of Hair Extraction and its Efficient Application on Growth Yield of Abelmoschus esculentus L

Comparative assessment of single-stage and two-stage anaerobic digestion for biogas production from high moisture municipal solid waste.

BackgroundAnaerobic digestion (AD) is a suitable process for treating high moisture MSW with biogas and biofertilizer production. However, the low stability of AD performance and low methane production results from high moisture MSW due to the fast acidify of carbohydrate fermentation. The effects of organic loading and incineration fly ash addition as a pH adjustment on methane production from high moisture MSW in the single-stage AD and two-stage AD processes were investigated.ResultsSuitable initial organic loading of the single-stage AD process was 17 gVS L−1 at incineration fly ash (IFA) addition of 0.5% with methane yield of 287 mL CH4 g−1 VS. Suitable initial organic loading of the two-stage AD process was 43 gVS L−1 at IFA addition of 1% with hydrogen and methane yield of 47.4 ml H2 g−1 VS and 363 mL CH4 g−1 VS, respectively. The highest hydrogen and methane production of 8.7 m3 H2 ton−1 of high moisture MSW and 66.6 m3 CH4 ton−1 of high moisture MSW was achieved at organic loading of 43 gVS L−1 at IFA addition of 1% by two-stage AD process. Biogas production by the two-stage AD process enabled 18.5% higher energy recovery than single-stage AD. The 1% addition of IFA into high moisture MSW was useful for controlling pH of the two-stage AD process with enhanced biogas production between 87–92% when compared to without IFA addition. Electricity production and energy recovery from MSW using the coupled incineration with biogas production by two-stage AD process were 9,874 MJ ton−1 MSW and 89%, respectively.ConclusionsThe two-stage AD process with IFA addition for pH adjustment could improve biogas production from high moisture MSW, as well as reduce lag phase and enhance biodegradability efficiency. The coupled incineration process with biogas production using the two-stage AD process was suitable for the management of MSW with low area requirement, low greenhouse gas emissions, and high energy recovery.

Exploring Biogas and Biofertilizer Production from Abattoir Wastes in Nigeria Using a Multi-Criteria Assessment Approach

Management of waste streams from abattoirs is a major challenge in developing countries. Harnessing these wastes as resources for the production of biogas and biofertilizer could contribute to curbing the environmental menace and to addressing the problems of energy and food deficits in Nigeria. However, large scale uptake of the technology is faced with techno-socio-economic and the lack of data required for effective investment decisions. In this study, the potential use of waste generated in the north central region of Nigerian abattoirs, representing approximately 12% of the land and 6% of the population, were evaluated for suitability for biogas and biofertilizer production. Data acquired from the study sites were used for computational estimation and integrated into strengths, weaknesses, opportunities, and threats (SWOT) analysis to give a detailed overview of the prospects and the limiting factors. The study revealed that high investment costs and public subsidies for fossil fuels are the key limiting factors while the prospects of tapping into the unexploited carbon markets and multiple socio-economic and environmental benefits favors investment. Public supports in the form of national policy reforms leading to intervention programs are required for progress.

Wastewater nutrient recovery using twin-layer microalgae technology for biofertilizer production.

This study evaluates the feasibility of advanced biofilm microalgae cultivation in a twin layer (TL) system for nutrient removal (N and P) as the tertiary treatment in small wastewater treatment plants (WWTPs) located in sensitive areas. Furthermore, the potential valorisation of microalgae biomass as a component of bio-based fertilizers is assessed. Scenedesmus sp. was chosen among 33 microalgae strains for inoculation of TL due to its high growth rate and its nutrient uptake capacity. The tests carried out in the prototype were markedly efficient for total soluble and ammoniacal nitrogen removal (up to 66 and 94%, respectively). In terms of potential valorisation of microalgae, the nutrient content was 5.5% N (over 40% protein), 8.8% P2O5 and 1.5% K2O, high enzymatic activity, very low levels of heavy metals and no detectable pathogen presence. However, in the formulation of solid-state bio-based fertilizers, the microalgae proportions in blends of over 2% of microalgae led to negative effects on ryegrass (Lolium perenne L. ssp.) and barley (Hordeum vulgare ssp.). The obtained results demonstrate that TL represents a promising technology, which allows efficient tertiary treatment of urban wastewater and the production of high-quality bio-based fertilizer.

Cultivation of microalgae for biofuel production: coupling with sugarcane-processing factories

BackgroundDespite their potential as biofuel resources, large-scale production of biofuels from microalgae is still uncertain primarily due to a lack of feasibility of the process and that it proves to be capital and energy intensive. Therefore, an integration of microalgal cultivation with other processes for achieving an inexpensive nutrient and energy use is an important issue. In the present study, the potential of the flue gas and the wastewater of a sugar factory to support microalgae growth for biofuel and bio-fertilizer production is evaluated.MethodsThe study was carried out by following a case study approach; an Ethiopian sugarcane-processing factory, Metahara sugar and ethanol production factory, was selected for this purpose. Conceptual microalgal biofuel production was integrated with the real sugarcane-processing factory, and the process was evaluated with regard to the product outputs and energy requirements.ResultsThe integrated process model shows that three products, biodiesel, upgraded biogas, and bio-fertilizer with production capacities of 188 tons/year, 1,974,882 m3/year and 42 tons/year, respectively, were produced. For the production of these products, the electricity and thermal energy demand of the integrated process amounted to 1822.13 and 3244.99 MWh/year, respectively. A sensitivity analysis shows that the oil content of the algae, the nitrogen content of the waste, the oil extraction efficiency, and the transesterification efficiency are the main factors which affect the biodiesel production capacity of the integrated process.ConclusionsThis case study approach investigated the potential of a future possible bio-refinery and environmental pollution reduction concept by integrating microalgae biomass production with sugarcane-processing factory wastes and by-products. It was found that the factory wastes and by-products have a significant potential for a viable biofuel production from microalgae.

Importance of Substrate and Microbes in Bio Fertilizer Production

Importance of Substrate and Microbes in Bio Fertilizer Production

Utilization of Microbial Diversity as Biofertilizers

Biofertilizers are the material which contains living microorganisms. When applied to plant surfaces, they promote plant growth by increasing the supply of primary nutrients to the host plants. Tremendous population increase put a pressure and high demand in agricultural productivity. This results in use of chemical fertilizers, pesticides as well as insecticides at large scale. Though it help in production of crops at a little higher rate but has adversely affected soil fertility. With the use of these chemical fertilizers soil is continuously losing its fertility and essential minerals. The best remedy to overcome this problem is to enhance production and use of biofertilizers. Biofertilizers result is slow in comparison to chemical fertilizers but is soothing and long lasting for soil and host plant. It is also cost effective when compared to chemical fertilizers. Microorganisms like bacteria, fungi and blue green algae are used as biofertilizers. They are effective in enhancing plant growth by several activities such as decomposition of organic materials, nitrogen fixation, suppression of plant diseases, increased nutrient availability, synthesis of antibiotics, phytostimulation, production of phytohormones etc. Biofertilizers include Plant Growth Promoting Rhizobacteria (PGPR), Arbuscular Mycorrhizal Fungi (AMF) and also Rhizobial Biofertilizers. The review provides comprehensive knowledge about the use of microbial diversity as Biofertilizers and its applications.

Bioremediation of Aquaculture Wastewater with Algal-Bacterial Biofilm Combined with the Production of Selenium Rich Biofertilizer

The discharge of aquaculture wastewater and the excessive selenium in aquaculture effluent caused by selenium addition to aquatic feed are posing a serious risk for the marine environment. In this study, batch tests were carried out to investigate the feasibility of utilizing algal–bacterial biofilm for the treatment of selenium-rich aquaculture wastewater. The effects of four different types of commercial biofilm carriers on the attached growth of biofilms and the contaminant removal capacity were examined. The braided cotton biofilm carrier had the best performance on biofilm growth, while in an exponential growth period the dry weight density of the biofilm was above 2.0 g L−1. By utilizing the braided cotton carrier with a hydraulic retention time (HRT) of 6 days, the removal rate of N and P from the raw aquaculture wastewater was 88.5 ± 6.2% and 99.8 ± 0.2%, respectively. After that, the effects of different initial wastewater load ratios (IWLR) and HRT on the effluent quality of the treatment process were studied. The decrease in IWLR and the extension of HRT could improve the treatment performance. The effluent N, P and Se concentrations in the group with 50% IWLR and 6-day HRT were 0.75 ± 0.10 mg L−1, 0.015 ± 0.02 mg L−1, 35.2 ± 3.2 μg L−1, respectively, indicating an effective removal of the main contaminants. The algal–bacterial biofilm harvested from the batch test was rich in N, P and Se, where the Se content was 21.8 ± 3.4 mg kg−1, which has the potential to be used as an Se-rich biofertilizer.

Assessment of biomass potentials of microalgal communities in open pond raceways using mass cultivation.

Metagenome studies have provided us with insights into the complex interactions of microorganisms with their environments and hosts. Few studies have focused on microalgae-associated metagenomes, and no study has addressed aquatic microalgae and their bacterial communities in open pond raceways (OPRs). This study explored the possibility of using microalgal biomasses from OPRs for biodiesel and biofertilizer production. The fatty acid profiles of the biomasses and the physical and chemical properties of derived fuels were evaluated. In addition, the phenotype-based environmental adaptation ability of soybean plants was assessed. The growth rate, biomass, and lipid productivity of microalgae were also examined during mass cultivation from April to November 2017. Metagenomics analysis using MiSeq identified ∼127 eukaryotic phylotypes following mass cultivation with (OPR 1) or without (OPR 3) a semitransparent film. Of these, ∼80 phylotypes were found in both OPRs, while 23 and 24 phylotypes were identified in OPRs 1 and 3, respectively. The phylotypes belonged to various genera, such as Desmodesmus, Pseudopediastrum, Tetradesmus, and Chlorella, of which, the dominant microalgal species was Desmodesmus sp. On average, OPRs 1 and 3 produced ∼8.6 and 9.9 g m−2 d−1 (0.307 and 0.309 DW L−1) of total biomass, respectively, of which 14.0 and 13.3 wt% respectively, was lipid content. Fatty acid profiling revealed that total saturated fatty acids (mainly C16:0) of biodiesel obtained from the microalgal biomasses in OPRs 1 and 3 were 34.93% and 32.85%, respectively; total monounsaturated fatty acids (C16:1 and C18:1) were 32.40% and 31.64%, respectively; and polyunsaturated fatty acids (including C18:3) were 32.68% and 35.50%, respectively. Fuel properties determined by empirical equations were within the limits of biodiesel standards ASTM D6751 and EN 14214. Culture solutions with or without microalgal biomasses enhanced the environmental adaptation ability of soybean plants, increasing their seed production. Therefore, microalgal biomass produced through mass cultivation is excellent feedstock for producing high-quality biodiesel and biofertilizer.

Corn Response to an Integrated Plant Nutrition System (IPNS) With Humic Acid and Biofertilizers

Sustainable agriculture production depends on the development of methods that optimize nutrient cycling, minimize use of external inputs, and maximize input use efficiency according to the conditions of each region. The principle of an integrated plant nutrition system (IPNS) is to tailor plant nutrition and soil fertility management, taking advantage of the combined and harmonious use of inorganic, organic and biological resources. This greenhouse study investigated the individual and combined use of inorganic, organic and biological fertilizer resources for corn (Zea mays L.). We evaluated the effects of commercial synthetic fertilizer, humic acid products, compost/manure teas and bioinoculant as inorganic, organic and biological resources, respectively, and their synergy on corn growth and soil respiration parameters under a period of water stress. The pots were laid out in completely randomized design and the total of sixteen treatment combinations were replicated four times. In general, when comparing to the control values, the use of humic acid (HA), biofertilizers and the integration of both compounds generated significantly greater early season plant height, chlorophyll content, photosynthetic efficiency and shoot/root dry biomass. The soil substrate induced respiration was affected by only one biofertilizer product at two different rates. Though all pots received adequate synthetic fertilizer, the control plants were generally smaller and less vigorous compared to the plants receiving either HA or biofertilizer treatments, but no additive benefit was observed for the integrated practice compared to individual applications. Further studies addressing different types and levels of stress along with greater stress duration should be conducted to validate these findings.