Phosphate Solubilizing Bacteria Research Articles

Phosphate-solubilizing bacteria improve the antioxidant enzyme activity of Potamogeton crispus L. and enhance the remediation effect on Cd-contaminated sediment

Phosphorus-solubilizing bacteria (PSB) assisted phytoremediation of cadmium (Cd) pollution is an effective method, but the mechanism of PSB-enhanced in-situ remediation of Cd contaminated sediment by submerged plants is still rare. In this study, PSB (Leclercia adecarboxylata L1-5) was inoculated in the rhizosphere of Potamogeton crispus L. (P. crispus) to explore the effect of PSB on phytoremediation. The results showed that the inoculation of PSB effectively improved the Cd extraction by P. crispus under different Cd pollution and the Cd content in the aboveground and underground parts of P. crispus all increased. The μ-XRF images showed that most of the Cd was enriched in the roots of P. crispus. PSB especially showed positive effects on root development and chlorophyll synthesis. The root length of P. crispus increased by 51.7%, 80.5% and 74.2% under different Cd pollution, and the Ca/Cb increased by 38.9%, 15.2% and 8.6%, respectively. Furthermore, PSB enhanced the tolerance of P. crispus to Cd. The contents of soluble protein, MDA and H2O2 in 5mg·kg-1 and 7mg·kg-1 Cd content groups were decreased and the activities of antioxidant enzymes were increased after adding PSB. The results showed that the application of PSB was beneficial to the in-situ remediation of submerged plants. Environment implicationHeavy metal pollution in sediment has a potential threat to the quality of water environment, and it is necessary to repair it. In-situ extraction of submerged plants is a green, low-cost and sustainable technology, but this technology has the problem of low plant biomass.In this study, a method of phosphate-solubilizing bacteria combined with submerged plant restoration was proposed, and the factors of phosphate-solubilizing bacteria promoting the growth of submerged plants and enhancing cadmium tolerance were analyzed. It provides a new idea for in-situ remediation of heavy metal pollution in sediment.

Growth, nutrient removal, and lipid productivity promotion of Chlorella sorokiniana by phosphate solubilizing bacteria Bacillus megatherium in swine wastewater: Performances and mechanisms

Effects of a phosphorus-solubilizing bacteria (PSB) Bacillus megatherium on growth and lipid production of Chlorella sorokiniana were investigated in synthesized swine wastewater with dissolved inorganic phosphorus (DIP), insoluble inorganic phosphorus (IIP), and organic phosphorus (OP). The results showed that the PSB significantly promoted the algal growth in OP and IIP, by 1.10 and 1.78-fold, respectively. The algal lipid accumulation was also greatly triggered, respectively by 4.39, 1.68, and 1.38-fold in DIP, IIP, and OP. Moreover, compared with DIP, OP improved the oxidation stability of algal lipid by increasing the proportion of saturated fatty acids (43.8 % vs 27.9 %), while the PSB tended to adjust it to moderate ranges (30.2–41.6 %). Further, the transcriptome analysis verified the OP and/or PSB-induced up-regulated genes involving photosynthesis, lipid metabolism, signal transduction, etc. This study provided novel insights to enhance microalgae-based nutrient removal combined with biofuel production in practical wastewater, especially with complex forms of phosphorus.

Role of Hazelnut Husk Compost and Phosphate Solubilizing Bacteria in Improving Productivity and Quality Parameters of Wheat (Triticum aestivum L.) and Their Effects on Some Soil Biological Properties

ABSTRACT Implementing compost can assist in improving soil structure and enable nutrient mobilization to plants that initiate an appropriate soil balance. In a greenhouse experiment, the influence of hazelnut husk compost (HHC), both in single and in combination with the phosphate solubilizing bacteria (PSB) on the wheat yield, yield parameters, and soil biological properties were investigated. A significant increase in yield and its quality parameters was recorded when the soil was treated with different doses of compost and bacteria. It was observed copious improvements in the soil biological properties with these applications. The microbial biomass carbon and total organic carbon ratios (Cmic:Corg) ranged from 1.51 to 2.09, were also remarkable in the organic amended soils. However, in all the treatments, the co-inoculation of bacteria with compost enhanced all the parameters significantly more than their individual applications. The highest yield increase over control (22.12%) was recorded from the integrated application of organic source and bio-fertilizer. This reflects a synergistic relationship between the compost and bacteria that eventually enhanced wheat production. It is therefore concluded that using HHC and PSB in soil can unfold promising possibilities for better soil health, which in the long run can contribute to sustainable food production.

Effects of organic amendments, biofertilisers and biodynamic preparations on soil properties and leaf nutrient concentrations in grapevine

ABSTRACT Excessive and unbalanced use of chemical fertilisers can lead to depletion of physical and chemical properties of the soil and have negative impacts on the environment. This investigation was conducted at Mizoram University, Aizawl, Mizoram, India and aimed to evaluate effects of organic amendments, biofertilisers and biodynamic preparations on soil properties and leaf nutrient status of grapevine. The experiment was laid out in randomised block design with 14 treatments consisting of different combinations of organic amendments, biofertilisers and biodynamic preparations viz. farmyard manure (FYM), vermicompost (VC), pig manure (PIM), neem cake (NC), Azospirillum, phosphate solubilising bacteria (PSB), potash solubilising bacteria (KSB), Trichoderma harzianum, cow pat pit (CPP) and biodynamic preparations BD500 and BD501. The results demonstrated that the use of organic amendments in combination with biofertilisers and biodynamic preparations enhanced leaf nutrient status as well soil properties in the vineyard. Among all the tested combinations, the highest concentrations of Mn, Zn, chlorophyll a, b and total chlorophyll in the leaves and concentrations of soil organic carbon, inorganic carbon, total carbon, total N, available N, P, K, Mn and Zn, cation exchange capacity (CEC) and abundance of bacteria and Actinomycetes in the soil were recorded with application of PIM + Azospirillum + PSB + KSB + T. harzianum + CPP + BD 500 + BD 501. This treatment was therefore recommended as a suitable option to meet the demand for long-term maintenance of soil fertility as well agroecosystem conservation and sustainability.

Relationships between soil compaction and soil physical-chemical-biological characteristics: A case study from volcanic agricultural soils of Entisol and Ultisol in North Maluku Province of Indonesia

Soil compaction has been recognized as a form of soil degradation that mostly deteriorates agricultural soil health worldwide from various climatic conditions and soil management. Heavy compaction can occur in agricultural soils due to intensive tillage, where its effects on soil properties have been the focus of many studies. The present study was undertaken to assess whether soil compaction occurs in agricultural soils adopting no-tillage systems and how the link between soil compaction and chemical-biological characteristics could be. A field investigation was carried out in two different locations that have different soil types, Entisol in Maitara Island and Ultisol in Halmahera Island, North Maluku Province. Sixteen undisturbed and disturbed soil samples were collected from each location grown with cassava and taken to the laboratory for analysis. Soil components observed included soil texture, bulk density, particle density, total porosity, soil permeability, soil organic matter (SOM), total nitrogen (N), phosphorous (P) availability, and phosphate-solubilizing bacteria (PSB). The findings revealed linear relationships between soil compaction and sand fraction, SOM, PSB, and available P, but none were found in soil total N. These results confirmed the importance of soil compaction management in food crop agricultural systems, particularly when soil carbon is low, to promote soil health. As the inconsistent correlation of soil compaction and chemical-biological properties was found in these two soil types, further investigation is necessary.

Response of green gram [Vigna radiata (L) Wilczek] to application of biofertilizers and phosphorus

The present study was carried out at the Crop Research Centre, Carrier Point University, Kota (Rajasthan), during the kharif season of 2020 and 2021 to assess the effect of phosphorus, rhizobium and phosphate solubilizing bacteria on growth and yield attributes of green gram. Significantly increase in growth, yield attributes and yield of green gram were recorded with the application of phosphorus 50 kg P2 O5 /ha. In case of biofertilizers (PSB, Rhizobium and PSB + Rhizobium), all growth and yield attributes and yield were increased significantly. However, among treatment combinations, the maximum values of these parameters were observed with 50 kg P2 O5 /ha + biofertilizers (PSB + Rhizobium) in comparison to all other treatment combinations. The net returns and B: C ratio were also higher under 50 kg P2 O5 /ha + biofertilizers (PSB + Rhizobium).

Comparison of bio-beads combined with Pseudomonas edaphica and three phosphate materials for lead immobilization: Performance, mechanism and plant growth

Phosphate materials (PMs) combine with phosphate solubilizing bacteria play an essential roles in lead (Pb) immobilization, but their resulting ability to reduce Pb bioavailability may vary depending on PMs used. In this study, Pseudomonas edaphica GAU-665 and three PMs: tricalcium phosphate, calcium phytate and nano-hydroxyapatite were respectively encapsulated into bio-beads by sodium alginate, which immobilization efficiency of Pb2+ were 99.11%, 97.76% and 99.02% at initial Pb2+ concentration of 200 mg L−1, respectively. The Pb2+ immobilization performance of bio-beads under different conditions and their organic acids secreted were examined. Most Pb2+ was immobilized by bio-beads through combined functions of adsorption, precipitation, ion exchange and biomineralization, accompanied by the formation of more stable compounds such as Pb3(PO4)2, Pb5(PO4)3OH and Pb5(PO4)3Cl. Meanwhile, pot experimental results indicated that the inoculation of CPhy (calcium phytate) bio-beads with PSB have highest biomass and root growth of oat (Avena sativa L.) in Pb-stressed compared with CK, which increased the content of chlorophyll b (167.51%) in shoot. In addition, the CPhy bio-beads enhance the peroxidase, catalase activities and reduce the malondialdehyde content to alleviating lead physiological toxicity in oat, which reductions the Pb accumulation in shoot (52.06%) and root (81.04%), and increased the residual fraction of Pb by 165.80% in soil. These findings suggest the bio-beads combined with P. edaphica GAU-665 and calcium phytate is an efficient Pb immobilization material and provided feasible way to improve safety agricultural production and Pb-contaminated soil remediation.

Integrated nutrient module: an efficient tool for sustainable farming of cape gooseberry (Physalis peruviana L.)

Cape gooseberry is a nutrient loving crop. But excessive use of inorganic fertilizers may leads to health hazards, ecological vulnerabilities and diminution of soil physico-chemical characteristics. Hence, a trial was conducted for substituting inorganic fertilizers with biofertilizer in cape gooseberry to maintain the yield potential with soil fertility status too. The experimental plants were treated with azotobacter, phosphate and potash solubilizing bacteria (PSB and KSB) at 10 g plant-1 each with reduced dose of recommended fertilizer (RDF) (100- 60%) for two consecutive growing season. Total harvestable fruit plant-1 with highest yield was recorded in 90% RDF + Azotobacter, PSB and KSB treatment with par value in 60% RDF + Azotobacter, PSB and KSB treatment. Quality of ripped fruit with respect to TSS (15.90 °B), total sugar  (11.29%), ascorbic acid (60.03 mg 100 g-1) and carotenoid content (49.25 µg 100 g-1) was also improved significantly in 60% RDF + Azotobacter, PSB and KSB treatment. Soil physico-chemical properties of the field was not varied significantly over initial reading. However, microbial population viz. bacteria, fungi and actinomycetes count was improved significantly in all the nutrient modules. Hence, it can be concluded that integrated nutrient module comprising 60% RDF of NPK + Azotobacter, PSB and KSB at 10 g plant-1 is the best treatment module for improving the production system of cape gooseberry in sustainable manner for long run without hampering the soil health and quality. Bangladesh J. Bot. 53(1): 83-90, 2024 (March)

Seed Coating Treatments and Foliar Spray of Micronutrients Enhance Quality of Harvested Seeds in Garden Pea (Pisum sativum L.)

To study the effect of different seed coating treatments and foliar application of micronutrients on quality seed production in pea, analysis of harvested seed was done at laboratory of the Department of Seed Science and Technology, Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan (HP). Seeds from field experiment were harvested and were evaluated in the laboratory conditions based on the different parameters. In field experiment, there were seven different treatments comprising, seed coating with Rhizobium, Phosphate solubilizing bacteria, iron, zinc, carbendazim along with control and foliar application of micronutrients. From the investigation, it was observed that seed coating with Rhizobium @ 30 g + PSB @ 30 ml kg-1 seed and two foliar sprays of ZnSO4 @ 0.3 % + FeSO4 @ 0.3 % at 50 per cent flowering and 15 days later, significantly improved the germination (96.00 %), seedling length (19.29 cm), seedling dry weight (34.80 mg), SVI-I (1851.62), SVI-II (3341.38), germination in accelerated ageing test and in cold test (77.75 % and 80 %, respectively) and resulted in the lowest EC (16.75 μS cm-1) of harvested seeds. Hence, it was concluded that seed coating with Rhizobium @ 30 g + PSB @ 30 ml kg-1 seed and two foliar sprays of ZnSO4 @ 0.3 % + FeSO4 @ 0.3 % performed best among all the treatments tested for quality seed production and it could be recommended for getting quality seeds in garden pea.

Microbial dynamics and dehydrogenase activity in tomato (Lycopersicon esculentum Mill.) rhizospheres: Impacts on growth and soil health across different soil types

Abstract The dehydrogenase activity (DHA) in the rhizospheres of tomatoes grown in different soil types – Khor Abu-Habil (KA), Bara (B), and Greenhouse (Gr) – in North Kordofan, Sudan, was determined. In addition, the abundance of soil microbes in the tomato rhizospheres during the two growth stages, after 45 and 90 days (short and long term), was analyzed. The KA site (clay soil) showed the highest DHA (81.79 CFUs/g) followed by the B site (63.76 CFUs/g) (sandy loam) after 90 days of sowing, and the Gr site showed the lowest DHA (44.50 CFUs/g) (loamy sand soil) after 45 days. Moreover, the presence of high microbial activity (total density counts, total fungi, phosphate-solubilizing bacteria, Streptomycetes sp., Azotobacter sp., Azospirillum sp., and Pseudomonas sp. density counts) after 90 days and minimum microbial abundance after 45 days were identified at all sites. The measured growth parameters of fresh and dry weight, in addition to the root-to-shoot ratio, increased significantly at the same KA site dominated by a higher microbial density after 90 days. During the long term, the growth stage was positively affected by the abundance of adapted microbials that improve and enhance plant growth.

Effect of Bio-Fertilizer Application on Agronomic Traits, Yield, and Nutrient Uptake of Barley (Hordeum vulgare) in Saline Soil.

Under salinity conditions, growth and productivity of grain crops decrease, leading to inhibition and limited absorption of water and elements necessary for plant growth, osmotic imbalance, ionic stress, and oxidative stress. Microorganisms in bio-fertilizers have several mechanisms to provide benefits to crop plants and reduce the harmful effect of salinity. They can be effective in dissolving phosphate, fixing nitrogen, promoting plant growth, and can have a combination of all these qualities. During two successful agricultural seasons, two field experiments were conducted to evaluate the effect of bio-fertilizer applications, including phosphate solubilizing bacteria (PSB), nitrogen fixation bacteria and a mix of phosphate-solubilizing bacteria and nitrogen fixation bacteria with three rates, 50, 75 and 100% NPK, of the recommended dose of minimal fertilizer on agronomic traits, yield and nutrient uptake of barley (Hordeum vulgare) under saline condition in Village 13, Farafra Oasis, New Valley Governorate, Egypt. The results showed that the application of Microbein + 75% NPK recorded the highest values of plant height, spike length, number of spikes/m2, grain yield (Mg ha-1), straw yield (Mg ha-1), biological yield (Mg ha-1), protein content %, nitrogen (N), phosphorus (P), potassium (K) uptakes in grain and straw (kg ha-1), available nitrogen (mg/kg soil), available phosphorus (mg/kg soil), total microbial count of soil, antioxidant activity of soil (AOA), dehydrogenase, nitrogen fixers, and PSB counts. The application of bio-fertilizers led to an increase in plant tolerance to salt stress, plant growth, grain yield, and straw yield, in addition to the application of the bio-fertilizers, which resulted in a 25% saving in the cost of mineral fertilizers used in barley production.

Phosphate bio-solubilization and cadmium tolerance interplay in the root-microbe interface and consequences on root P absorption in wheat

Functional soil microbial communities, including phosphate solubilizing bacteria (PSB), are known for their ability to enhance P availability along with additional properties such as the immobilization of trace elements like cadmium (Cd). Bacterial P solubilization and tolerance to Cd are important biological processes that might occur simultaneously with positive influence on plant growth, thus physiological mechanisms controlling both processes need to be deciphered. This interplay was investigated in three PSB isolates (Bacillus siamensis "B. Siam", Rahnella aceris "R. Acer" and Bacillus cereus "B. Cer") and their consortium (PSBCs) with contrasting P solubilizing capacities (high-medium-low), through bacterial culture-based and plant inoculation experiments under increasing Cd concentrations and low P availability conditions (Tri-calcium P "TCP" and Rock P "RP"). Results show that PSB, particularly R. Acer and PSBCs, significantly increased P bioavailability (from TCP) under increasing Cd2+ concentrations (33 ppm “Cd33”, 67 ppm “Cd67”, 134 ppm “Cd134” and 201 ppm “Cd201”). The enhanced bioavailable P strongly correlated (B. Siam and PSBCs) with Cd bioaccumulation capacity, phosphatase enzyme activity, and organic acids (OA) production. Co-application of RP and PSB inoculation under Cd2+ stress (Cd8 and Cd16) improved wheat seedling root growth, P acquisition, and root hairs density in the piliferous zone and root cap. Moreover, inoculation with B. Cer significantly improved root inorganic P (Pi) (384 and 752%) and root acid phosphatases (176 and 131%) under Cd8 and Cd16 compared to uninoculated Cd-stressed seedlings. Such a beneficial root adaptation mechanism could be explained by the significant correlations (mainly under Cd16) between Pi content and morphological traits of wheat roots. Findings from this study demonstrate that P solubilization and Cd tolerance are likely interconnected rhizosphere processes triggered by inoculation that presumably induced the elongation of root hairs and likely the rigidity of the root cell wall to reduce Cd entrance while increasing P acquisition.

Endophytic Bacillus vallismortis and Bacillus tequilensis bacteria isolated from medicinal plants enhance phosphorus acquisition and fortify Brassica napus L. vegetative growth and metabolic content.

Phosphorus fertilization imposes critical limitations on crop productivity and soil health. The aim of the present work is to explore the potential of two phosphate solubilizing bacteria (PSB) species in phosphorus supplementation of canola (Brassica napus L.). Out of 38 bacterial isolates obtained from nine medicinal plants, two bacterial strains (20P and 28P) were proved as the most potent for the in-vitro tricalcium phosphate solubilization test. These isolates verified their activity toward different enzymes as nitrogenase and alkaline phosphatase. Also, 20P and 28P gave a high amount of indole-3-acetic acid, 34.16 μg/ml and 35.20 μg/ml, respectively, and were positive for siderophores production as they detected moderate affinity for iron chelation. Molecular identification confirmed that strain 20P was Bacillus vallismortis and strain 28P was Bacillus tequilensis. A pot experiment was conducted to study the effect of four different phosphorus concentrations (0%, 50%, 75%, and 100% P) each alone and/or in combination with B. vallismortis, B. tequilensis, or both bacterial isolates on the vegetative growth and some physiological parameters of canola. The combined treatment of 50% phosphorus + (B. vallismortis + B. tequilensis) was generally the most effective with respect to shoot height, shoot dry mass, leaf area, photosynthetic pigment fractions, total sugar content, and accumulated NPK content. In contrast, the rhizosphere pH reached the minimum value under the same treatment. These findings highlighted the potential use of PSB (B. vallismortis and B. tequilensis) along with phosphorus fertilization as a safe sustainable tactic.

Effect of Organic and Inorganic Sources of Nutrients on Growth and Yield of Timely Sown Wheat (Triticum aestivum L.)

A comprehensive study examining the effects of organic and inorganic nutrient sources on the growth and yield of wheat was carried out during the Rabi season of 2020-21 at the Student's Instructional Farm, C.S. Azad University of Agriculture and Technology, Kanpur. The experimental design was a Randomized Block Design, with each treatment replicated three times across eight different treatments: Control (T1), 100% Recommended Dose of Fertilizers (RDF) (120:60:40 NPK kg/ha) (T2), RDF + Azotobacter (T3), RDF + Azotobacter + Farmyard Manure (FYM) @ 2.0 tons/ha + Phosphate Solubilizing Bacteria (PSB) @ 6.0 kg/ha + Trichoderma @ 5.0 kg/ha (T4), RDF + Vermicompost @ 2.5 tons/ha (T5), RDF + FYM @ 2.0 tons/ha + Vermicompost @ 1.0 ton/ha + Trichoderma @ 5.0 kg/ha (T6), RDF + FYM @ 2.0 tons/ha + Vermicompost @ 1.0 ton/ha + PSB @ 6.0 kg/ha + Azotobacter (T7), and RDF + FYM @ 2.0 tons/ha + Vermicompost @ 1.0 ton/ha + Azotobacter + PSB @ 6.0 kg/ha + Zinc @ 5.0 kg/ha + Sulphur @ 25 kg/ha (T8). The soil type was sandy loam with a pH of 8.13. The wheat variety Shekhar (K-1006) was planted on November 30, 2020, with a seed rate of 100 kg/ha and row spacing of 20 cm. The results indicated that the T8 treatment, which combined RDF, FYM, Vermicompost, Azotobacter, PSB, Zinc, and Sulphur, significantly improved plant growth characteristics such as height, fresh weight, dry weight, and number of tillers per plant, as well as yield-contributing factors including spike length, number of grains per spike, and test weight, compared to all other treatments. Specifically, the T8 treatment produced the highest grain yield, straw yield, and biological yield, recording 52.77, 67.55, and 120.32 quintals per hectare, respectively, which was significantly higher than the yields in treatments T1, T2, T3, and T4, and comparable to those in treatments T5, T6, and T7. Moreover, the T8 treatment achieved the highest gross income (Rs. 143,076.00), net income (Rs. 86,300.00), and benefit-cost ratio (2.52) when compared to all other treatments.

Phosphate-solubilizing bacteria increase maize phosphorus uptake from magnesium-enriched poultry manure biochar

Phosphate-solubilizing bacteria increase maize phosphorus uptake from magnesium-enriched poultry manure biochar

Ameriolations with VAM and PSB Inoculation of Growth and yield attributes in Pea (Pisum sativum L.) cv. Arkel

Background: Pea (Pisum sativum L.) is one of the most important legume grown all over the world with its varied uses as vegetables and other processed products. Its production and productivity in recent times have witnessed a diminishing graph due to numerous biotic and abiotic stresses. With unexploited use of synthetics in legume crops number of nodule formation have reduced to lowest levels. VAM (Vesicular Arbuscular Mycorrhiza) and PSB (Phosphate Solubilizing Bacteria) inoculation in soil have been observed in enhancing number of nodules, levels of NPK uptake and yield in pea. Methods: Considering the importance of above facts and experiment was laid in 2022 with RBD with three replications containing 7 treatments viz. T1 (Control), T2 (75% RDF + 25% PSB), T3 (50% RDF + 50% PSB), T4 (75% RDF + 25% VAM), T5 (50% RDF + 50% VAM), T6 (75% RDF + 12.5% VAM + 12.5% PSB) and T7 (50% RDF + 25% VAM + 25% PSB). Result: Investigations indicated that the treatment T7 (50% RDF + 25 % VAM + 25% PSB) showed significantly high growth, yield and quality like plant height (113.90 cm), number of leaves (87.09), number of branches (20.2), number of nodules (90.56), numbers of pod/plant (19.1), pod length (8.97 cm), number of seeds per pod (8.23), green pod yield/plot (4.80 kg), green pod yield/ha (80.12 q) compared to control. Hence, T7 (50% RDF + 25% VAM + 25% PSB) evidently exhibited a conglomeration of bio nutrient uptake enhancers resulting in maximum yield and quality.

Mitigating the effects of water-deficit stress on potato growth and photosynthesis using mycorrhizal fungi and phosphate-solubilizing bacteria

Abstract Biofertilizers, such as arbuscular mycorrhiza fungi and phosphate-solubilizing bacteria (PSB), have been reported to enhance plant growth under water stress conditions. This study aimed to investigate the effect of different biofertilizers on potato photosynthesis and growth under water deficit stress. The experiment was conducted over two crop years (2019 and 2020) using a randomized complete block design with three replications. Four irrigation intervals (70, 90, 110 and 130 mm of cumulative evaporation) and six biofertilizer treatments (PSB, Funneliformis mosseae [FM], Rhizoglomus fasciculatum [RF], PSB + FM, PSB + RF and no use) were applied. Severe moisture stress (130 mm evaporation) compared to no stress (70 mm evaporation) increased substomatal carbon dioxide concentration. The application of biofertilizers improved tuber yield under severe moisture stress, with FM showing the highest increase (62.9%), followed by RF (59.8%) and PSB (48.4%). The use of PSB along with mycorrhizae led to a significant decrease in mycorrhizal colonization percentage at all irrigation levels. The highest percentage of colonization and net photosynthesis was obtained from the application of both mycorrhizal species under irrigation conditions after 70 mm of evaporation. The application of PSB alone resulted in a 14.6% increase in the transpiration rate, additionally, the use of mycorrhiza led to an 18.7% increase in stomatal conductivity compared to no-biofertilizer. The results suggest that the simultaneous use of PSB and mycorrhizae can be effective in mild moisture stress, but in severe moisture stress, the use of mycorrhizal species alone is more effective.

Millets based alternative sustainable cost-effective culture media for microbial growth

Millets are a rich source of starch, proteins, lipids, and other nutrients. This study aimed to assess whether millets can be used to formulate sustainable and economically viable culture media, thus potentially replacing the expensive traditional media used for growing microorganisms. Millet samples from Maharashtra, Rajasthan, and Tamil Nadu were assayed for their protein and lipid content. Sorghum vulgare (Jowar), Pennisetum glaucum (Bajra), and Eleusine coracana (Ragi) demonstrated high protein content ranging from 0.63–0.78 mg/ml. Using Thin Layer Chromatography, lipids extracted with hexane were fractionated into several bands and compared against standard fatty acids and cholesterol. Panicum miliaceum (Proso) and Setaria italica (Kang) showed the maximum levels of free fatty acids and cholesterol. Based on the protein, lipid, and nutrient content, millets were used in different compositions to formulate media for growing bacteria and fungi. A mixture of Ragi and Bajra, which serves as calcium and phosphate sources respectively, exhibited zones of phosphate solubilization, thus confirming its potential as an alternative to Pikovskaya medium, which is used to cultivate phosphate- solubilizing bacteria. A mixture of Varai and Rajgira, which serves as carbohydrate and protein sources respectively, showed luxurious growth of fungi, thus confirming its potential as an alternative to Sabouraud’s Agar medium. Phosphate-solubilising bacteria are utilized in biofertilizer formation, thereby contributing to increased agricultural productivity. Besides proving a sustainable, environmentally friendly, and cost-effective alternative, the use of millets for media preparation can boost the agriculture sector and the economy of farmers as well.

Knowledge Level of Farmers on Utilization of Biofertilizers in Annamayya District of Andhra Pradesh

Indian agriculture has changed since the green revolution era. The major thrust of the green revolution is to ensure maximizing food grain production through a package of practices, ensuring assured irrigation and applying higher doses of chemical fertilizers to tap the potential of high-yielding varieties. Biofertilizers are safer for soil health as well as for the ecosystem. Biofertilizers are defined as preparations containing living cells or latent cells of efficient strains of microorganisms that help crop plants uptake nutrients by their interactions in the rhizosphere when applied through seed or soil. Thus, the present study was conducted to evaluate the knowledge level of farmers on utilizing biofertilizers in Annamayya district of Andhra Pradesh. A total of 60 farmers were purposively selected for the study. Ex-post-facto research design was followed. Data were collected with the help of an interview schedule, and the collected data were analyzed with the help of statistical measures like frequency, percentage, mean, and standard deviation. The results of the study revealed that 88.33 of respondents were using biofertilizers without mixing with chemical fertilizers, 80.00 of respondents have knowledge on the expiry date of powder form of biofertilizers, regarding source of availability, 66.66 reported that they avail biofertilizers from research stations, 61.66 per cent of respondents have knowledge on Phosphate Solubilizing Bacteria (PSB) among the type of biofertilizers used. The major constraints faced by the respondents in utilizing the biofertilizers were Lack of separate marketing facilities for crops produced using biofertilizers (71.66%) and Non-availability of biofertilizers locally at times when needed (66.67%) and suggestions were Provision of better marketing facilities for crops produced using biofertilizers (86.66%) and Biofertilizers should be available in time at local level (76.66%).

Divergent responses of phosphorus solubilizing bacteria with P-laden biochar for enhancing nutrient recovery, growth, and yield of canola (Brassica napus L.)

The growing global population has led to a heightened need for food production, and this rise in agricultural activity is closely tied to the application of phosphorus-based fertilizers, which contributes to the depletion of rock phosphate (RP) reserves. Considering the limited P reserves, different approaches were conducted previously for P removal from waste streams, while the adsorption of ions is a novel strategy with more applicability. In this study, a comprehensive method was employed to recover phosphorus from wastewater by utilizing biochar engineered with minerals such as calcium, magnesium, and iron. Elemental analysis of the wastewater following a batch experiment indicated the efficiency of the engineered biochar as an adsorbent. Subsequently, the phosphorus-enriched biochar, hereinafter (PL-BCsb), obtained from the wastewater, underwent further analysis through FTIR, XRD, and nutritional assessments. The results revealed that the PL-BCsb contained four times higher (1.82%) P contents which further reused as a fertilizer supplementation for Brassica napus L growth. PL-BCsb showed citric acid (34.03%), Olsen solution (10.99%), and water soluble (1.74%) P desorption. Additionally, phosphorous solubilizing bacteria (PSB) were incorporated with PL-BCsb along two P fertilizer levels P45 (45 kg ha−1) and P90 (90 kg ha−1) for evaluation of phosphorus reuse efficiency. Integrated application of PL-BCsb with half of the suggested amount of P45 (45 kg ha−1) and PSB increased growth, production, physiological, biochemical, and nutritional qualities of canola by almost two folds when compared to control. Similarly, it also improved soil microbial biomass carbon up to four times, alkaline and acid phosphatases activities both by one and half times respectively as compared to control P (0). Furthermore, this investigation demonstrated that waste-to-fertilizer technology enhanced the phosphorus fertilizer use efficiency by 55–60% while reducing phosphorus losses into water streams by 90%. These results have significant implications for reducing eutrophication, making it a promising approach for mitigating environmental pollution and addressing climate change.