Biological Fertilizers Research Articles

Bio-priming Treatment with PGPB Strains in Cowpea Production Increases Grain Yield and Net Income

In the 21st century, the use of beneficial microorganisms as biological fertilizers has become a notable phenomenon, driven by the ongoing search for sustainable solutions due to environmental issues associated with synthetic fertilizer use. This study aimed to investigate the effect of bio-priming with plant growth-promoting bacteria (PGPB) strains comparing them with synthetic fertilizer and rhizobium inoculation in Siirt ecological conditions. The field experiment was laid out according to a completely randomized design with four replications in the arable land of Siirt University (Siirt, Türkiye) during the 2019 summer season. Three synthetic fertilizer doses as diammonium phosphate (SF1: 100 kg ha-1, SF2: 200 kg ha-1, SF3: 300 kg ha-1) and seven biological fertilizer treatments (B1: TV61C, B2: TV62C, B3: TV126C, B4: TV24C, B5: TV53D, BMIX: TV119E+TV126C, RZB: Bradyrhizobium sp.) were compared with control (no fertilization+hydro-priming) in the study. The research results indicated that 300 kg ha-1 DAP and PGPB consortia showed the best results on agronomic characteristics. However, particularly when applied in the form of a consortium, PGPB strains exhibited performance very close to synthetic fertilization. Moreover, it was determined that 300 kg ha-1 DAP and PGPB consortia increased grain yield over hydro-primed plants by 54.6% and 42.4%, while they provided a net income of $654 and $721.6, respectively. Thus, bio-priming with PGPB increased higher net income compared with synthetic fertilizer due to lower treatment costs. In conclusion, bio-priming with PGPB strains has the potential of useful, sustainable and cost-effective strategy in cowpea production.

Impact of biological manure substitution on grain yield, nitrogen recovery efficiency, and soil biochemical properties.

Fertilization plays a crucial role in ensuring global food security and ecological balance. This study investigated the impact of substituting innovative biological manure for chemical fertilization on rice (Oryza sativa L) productivity and soil biochemical properties based on a three-year experiment. Our results suggested rice yield and straw weight were increased under manure addition treatment. Specifically, 70% of total nitrogen (N) fertilizer substituted by biological manure derived from straw, animal waste and microbiome, led to a substantial 13.6% increase in rice yield and a remarkable 34.2% boost in straw weight. In comparison to the conventional local farmer practice of applying 165 kg N ha-1, adopting 70% of total N plus biological manure demonstrated superior outcomes, particularly in enhancing yield components and spike morphology. Fertilization treatments led to elevated levels of soil microbial biomass carbon and N. However, a nuanced comparison with local practices indicated that applying biological manure alongside urea resulted in a slight reduction in N content in vegetative and economic organs, along with decreases of 10.4%, 11.2%, and 6.1% in N recovery efficiency (NRE), respectively. Prudent N management through the judicious application of partial biological manure fertilizer in rice systems could be imperative for sustaining productivity and soil fertility in southern China.

Agroecological and economic assessment of organic crop rotation in Polissia zone

For the organic production of plant products on sod-podzolic soil, a biologized short-rotational grain rotation was put to study: sorghum–oats–oats– vicot–oats–barley. In conditions of shortage of manure, the optimization of the nutrition system is carried out due to the by-products of grain and leguminous crops, oil radish siderate, the use of foliar treatment of crops with preparations of biological origin (microfertilizer Avatar, biopreparation BiocomplexBTU and liquid biofertilizer Volynski humaty), including, in the background mineral fertilizers allowed in organic production (P40K60 — phosphorite flour and potassium sulfate). The goal of the task was to investigate the influence of the biological fertilization system on crop rotation productivity, grain quality, soil fertility, and the economic efficiency of crop cultivation. It was established that, on average, during the 2021–2023 research, the maximum grain yield indicators were obtained for all factors of influence: pea-oats — 2.25 t/ha, oats — 1.88, vetch-oats — 1.66 and barley — 1.61 t/ha, the total crop rotation productivity under these conditions was 2.28 t grain units. It was determined that the protein content of oat grains was 9.1–9.8%, barley — 10.8–11.7%, the protein content of flax seeds was at the level of 18.2–19.0%, vetch — 22.9–23.8%, the lowest indicators were noted in the control. It has been established that in biological crop rotation due to 50% saturation with leguminous crops against the background of straw and siderate, a deficit-free balance of humus and nutrients is achieved. Due to the by-products of crops, 175 kg of humus accumulates in the soil annually, which ensures a simple reproduction of its fertility, and the additional application of fertilizers of biological origin helps to increase the humus to 350 kg, which ensures an extended reproduction of the fertility of sod-podzolic soil. Nitrogen comes at the expense of oil radish siderate, with by-products of leguminous crops and is biologically fixed from the atmosphere. Removal of phosphorus and potassium by crops is compensated by the supply of these elements with straw and siderate. Due to the disparity of prices, the cultivation of grain crops was unprofitable under all factors of influence, the profitability of legumes was 19.6–64.4%. The level of profitability of the general crop rotation for the treatment of crops with drugs was 6.5–14.8%, and the costs incurred for the purchase and application of phosphorus-potassium fertilizers did not pay off with the growth of crop yields.

A combination of biochemical fertilizers enhances plant nutrient absorption, water deficit tolerance, and yield of chickpea (Cicer arietinum L.) plants under irrigation regimes

Water shortage is the most critical abiotic stress and adversely impacts crop growth and productivity. Biofertilizers are an environmentally friendly method for sustainable agricultural development and improving plant water deficit tolerance. The effects of biological and chemical fertilizers on yield, yield components, and nutrient absorption of chickpea plants were studied in 2018 and 2019. The main plots were assigned to the irrigation levels [80% (I80) and 50% (I50)] and the subplot was assigned to 13 fertilizer combinations including free-living N-fixing bacteria (NB), potassium solubilizing bacteria (KB), phosphate solubilizing bacteria (PB), common chickpea nutrition program (F; NPK chemical fertilizer), and their combination. The results showed that shoot phosphorus content was increased by 80% when F + NPB (NPK chemical fertilizer and N + P biofertilizers) was applied at I80 compared with the control at I50. Furthermore, I80 and the application of PKB (P + K biofertilizers) and NPKB (N + P + K biofertilizers) obtained the highest shoot K and N concentrations, respectively. The NPKF + B-treated plants (N + P + K chemical fertilizer and N + P + K biofertilizers) demonstrated superior growth attributes such as plant height and the number of sub-branches at I80. The highest grain yield was obtained from the NPKF + B treatment at I80, which was 7.1-fold higher compared with the control at I50. In general, the combined application of biochemical fertilizers mitigated the adverse effect of water deficit and improved nutrient absorption and chickpea yield. The use of biochemical fertilizers can be efficient in reducing the consumption of chemical fertilizers and achieving sustainable agricultural goals.

Biofertilization with Liquid Vermicompost-Activated Biochar Enhances Microbial Activity and Soil Properties

Biochar (Bc) and liquid vermicompost extracts (LVEs) are increasingly being used as biofertilizers in agriculture to promote soil-microbe-crop interactions. However, although both these products can potentially act synergistically due to their complementary characteristics, their co-application in different soils has not yet been investigated. Therefore, firstly, an LVE-activated biochar (BLVE) was experimentally formulated and the persistence of LVE bacteria over a 60-day storage period was determined. The total number of LVE bacteria increased by 10-fold after 7 days and was stable throughout the entire biochar storage period. In addition, changes in the composition of the bacterial community were observed after 30 days of storage, indicating that taxa less represented in pure LVE may be advantaged upon biochar colonization. Secondly, a microcosm experiment was performed to evaluate whether the biological fertility and enzyme activities of two soils, differing in organic matter content, could be enhanced by the addition of LVE-activated biochar. In this experiment, three different doses of Bc, LVE, and BLVE against the carbon-related biological fertility index (i.e., biological fertility index, BFI) and three enzyme activities over a 21-day incubation period were tested. The BLVE treatment yielded the best results (i.e., BFI +32%, enzyme activities +38%). This indicates that Bc and LVEs can act synergistically to promote soil fertility, quality, and microbial activity. By integrating LVE-activated biochar into their soil management practices, farmers could achieve higher crop yields and healthier products.

Effect of common horsetail extract on growth characteristics, essential oil yield and chemical compositions of basil (Ocimum basilicum L.)

To investigate the effect of horsetail extract containing high silicon on morphological traits, growth, content, and compositions of essential oil of sweet basil (Ocimum basilicum L.) an experiment turned into carried out in the shape of a randomized complete block design with three replications. Foliar treatment of horsetail extract with zero, 0.5, 1, and 2% concentrations was applied on 6–8 leaf plants. The assessed traits include plant height, number of leaves per plant, number of sub-branches, leaf area index, plant fresh weight, plant dry weight, total anthocyanin, the content of total phenol and total flavonoid, antioxidant activity, essential oil content, and compounds were measured. The findings demonstrated that the increase of silicon-containing horsetail extract enhanced the improved increase in growth and phytochemical trait values. The use of horsetail extract in the 2% treatment increased plant height, the number of leaves per plant, the number of sub-branches, leaf area index, fresh weight, and dry weight of the plant by 49.79, 45.61, 91.09, 99.78, 52.78 and 109.25%, respectively, compared to the control. The highest content of total phenol (2.12 mg GAE/g DW), total flavonoid (1.73 mg RE/g DW), total anthocyanin (0.83 mg C3G/g DW), and antioxidant activity (184.3 µg/ml) was observed in the 2% extract treatment. The content of essential oil increased with increasing the concentration of horsetail extract, so the highest amount of essential oil was obtained at the concentration of 2%, which increased by 134.78% compared to the control. By using GC–MS, the essential oil was analyzed. The main components of the essential oil include methyl eugenol (12.93–25.93%), eugenol (17.63–27.51%), 1,8-cineole (15.63–20.84%), linalool (8.31–19.63%) and (Z)-caryophyllene (6.02–14.93%). Increasing the concentration of horsetail extract increased the compounds of eugenol, 1,8-cineole, and linalool in essential oil compared to the control, but decreased the compounds of methyl eugenol and (Z)-caryophyllene. Foliar spraying of horsetail extract, which contains high amounts of silicon, as a stimulant and biological fertilizer, can be a beneficial ingredient in increasing the yield and production of medicinal plants, especially in organic essential oil production.

Effects of Bacillus subtilis on Cucumber Seedling Growth and Photosynthetic System under Different Potassium Ion Levels.

Potassium deficiency is one of the important factors restricting cucumber growth and development. This experiment mainly explored the effect of Bacillus subtilis (B. subtilis) on cucumber seedling growth and the photosynthetic system under different potassium levels, and the rhizosphere bacteria (PGPR) that promote plant growth were used to solubilize potassium in soil, providing theoretical support for a further investigation of the effect of biological bacteria fertilizer on cucumber growth and potassium absorption. "Xinjin No. 4" was used as the test material for the pot experiment, and a two-factor experiment was designed. The first factor was potassium application treatment, and the second factor was bacterial application treatment. The effects of different treatments on cucumber seedling growth, photosynthetic characteristics, root morphology, and chlorophyll fluorescence parameters were studied. The results showed that potassium and B. subtilis had obvious promotion effects on the cucumber seedling growth and the photosynthesis of leaves. Compared with the blank control, the B. subtilis treatment had obvious effects on the cucumber seedling height, stem diameter, leaf area, total root length, total root surface area, total root volume, branch number, crossing number, gs, WUE, Ci, and A; the dry weight of the shoot and root increased significantly (p ≤ 0.05). Potassium application could significantly promote cucumber growth, and the effect of B. subtilis and potassium application was greater than that of potassium application alone, and the best effect was when 0.2 g/pot and B. subtilis were applied. In conclusion, potassium combined with B. subtilis could enhance the photosynthesis of cucumber leaves and promote the growth of cucumber.

Drought stress tolerance and metabolomics of Medicago sativa induced by Bacillus amyloliquefaciens DGL1.

This study used Bacillus amyloliquefaciens DGL1 isolated from the arid sandy land of the Qinghai-Tibetan Plateau as the research strain and investigated the effects of DGL1 on the biomass, physiology, and metabolites of Medicago sativa under different intensities of drought stress to provide a high-quality bacterial source and a theoretical basis for the research and development of biological fertilizer suitable for arid areas. The exopolysaccharides (EPS), 1-Aminocyclopropane-1-carboxylate deaminase (ACC), and phosphorus solubilizing capacity of DGL1 were determined. The effects of a DGL1 suspension on alfalfa biomass, physiological indexes, degree of peroxidation of cell membranes, and activity of antioxidant enzymes were determined after irrigating roots under drought stress. The effects on soil physicochemical properties were also evaluated, and metabolomics analysis was performed to explore the effect of DGL1 on the metabolites of alfalfa under drought stress. Strain DGL1 produced extracellular polysaccharide EPS and ACC deaminase and was capable of phosphorus solubilization. Treatment with DGL1 increased the biomass of alfalfa under different degrees of drought stress, significantly increased the activities of alfalfa antioxidant enzymes Super Oxide Dismutase (SOD), Peroxidase (POD), and catalase (CAT), reduced the content of MDA and H2O2, and increased the content of quick-acting phosphorus, quick-acting potassium, ammonium nitrogen, and nitrate nitrogen in the soil, thus improving soil fertility. Through metabolomics analysis, DGL1 was shown to affect amino acid metabolic pathways, such as arginine, leucine, glutamate, and tyrosine, as well as the levels of energy-providing polysaccharides and lipids, in alfalfa under 15% PEG-6000 drought stress, enhancing alfalfa's capacity to resist drought stress. Strain DGL1 enhances the drought suitability of alfalfa and has the potential for dryland development as a biological agent.

Combined Effect of Biological and Organic Fertilizers on Agrobiochemical Traits of Corn (Zea mays L.) under Wastewater Irrigation.

Corn (Zea mays L.) is an important annual grain that is cultivated as a food staple around the world. The current study examined the effect of wastewater and a combination of biological and organic fertilizers on the morphological and phytochemical traits of corn, using a factorial experiment based on a randomized complete block design with three replications. The first factor was biological and organic fertilizers at seven levels, including the control (no fertilization), bacterial biological fertilizers (NPK) along with iron and zinc Barvar biofertilizers, fungal biofertilizers made from Mycorrhiza and Trichoderma, biochar, a combination of bacterial and fungal biofertilizers, and a combination of bacterial and fungal biofertilizers with biochar. The second factor was irrigation at two levels (conventional irrigation and irrigation with wastewater). The traits studied included the morphological yield, phenols, flavonoids, polyphenols, glomalin, cadmium content in plant parts, and translocation factor (TF). The results disclosed that the best treatment in regard to the morphological traits was related to conventional water + biochar + mycorrhiza + Trichoderma + NPK. The highest phenol and flavonoid content were observed when biochar + mycorrhiza + Trichoderma + NPK treatments were used in both water treatments. Also, the wastewater + biochar + mycorrhiza + Trichoderma + NPK treatment demonstrated the highest total glomalin and phenylalanine ammonia-lyase (PAL) activity. The obtained results demonstrate that combined biological and organic fertilizer use on corn plants can effectively alleviate the deleterious effects of cadmium present in wastewater.

Plant growth-promoting rhizobacteria (PGPR) improve the growth and quality of several crops

Plant growth-promoting rhizobacteria (PGPR) are known to have the effect of promoting plant growth. In this paper, three PGPR strains were selected from the previous work, which had plant growth-promoting activities such as phosphate solubilization, nitrogen fixation, phosphorus mobilization, etc. These strains named FJS-3(Burkholderia pyromania), FJS-7(Pseudomonas rhodesiae), and FJS-16(Pseudomonas baetica), respectively, were prepared into solid biological agents. Three widely planted commercial crops (tea plant, tobacco, and chili pepper) were selected for PGPR growth promotion verification. The results showed that the new shoots of tea seedlings under PGPR treatment were much more than the control. We also used tobacco, another important crop in Guizhou, to test the growth-promoting effect of individual bacteria, and the results showed that each of them could promote the growth of tobacco plants, and FJS-3(Burkholderia pyrrocinia) had the best effect. In addition, we carried out experiments on tobacco and pepper using multi-strain PGPR, the tobacco plants' height, fresh, and root weight increased by 30.15 %, 37.36 %, and 54.5 %, respectively, and the pepper plants' increased by 30.10 %, 56.38 % and 43.18 %, respectively, which both showed significantly better effects than that of a single strain. To further test the field performance, field trials were carried out in a mature Longjing43 tea plantation in Guizhou. There were four treatments: no fertilization (T1), combined application of PGPR biological agent and compound fertilizer (T2), only application of PGPR (T3), and only application of compound fertilizer (T4). In terms of yield, grouped with or without PGPR, there was a 15.38 % (T2:T4) and 92.31 % (T3:T1) increase between them, respectively. The tea's yield and tea flavor substances such as tea polyphenols, caffeine, and theanine were detected, and the T2 showed the most significant positive effect on both sides. Especially, an important indicator of Matcha green tea is the color, chlorophyll content was then tested, and PGPR application increased it and improved the appearance. All these results demonstrated that the PGPR we screened could significantly promote plant growth and quality improvement, and had good application potential in crop planting, which could contribute to environmental protection and economic growth.

Pemanfaatan Limbah Kulit Pisang dan Kulit Nanas sebagai Bahan Baku Pembuatan Pupuk Organic Cair (POC)

Organic fertilizers are defined as fertilizers derived from plants or animals that have gone through an engineering process to improve soil biological, physical, and chemical properties. Organic fertilizers in this study were made from basic ingredients in the form of waste banana peels and pineapple peels. Pineapple and banana peels are often found in the form of waste from food and beverage processing facilities that are collected and not used. Therefore, in this study we made liquid organic fertilizer (POC) from banana and pineapple peel waste. The purpose of this study was to examine the quality of liquid organic fertilizer (POC) products with parameters of pH, temperature, and C-Organic content compared with quality standards according to the Decree of the Minister of Agriculture of the Republic of Indonesia No. 261 / KPTS / SR.310 / M / 4/ 2019 concerning Minimum Technical Requirements for Organic Fertilizers, Biological Fertilizers and Soil Improvements. The production of POC in this study was carried out using the anaerobic method, where the fermentation process itself was carried out for 14 days using Effective Microorganisms (EM4) as a bioactivator. The results of this study indicate that the highest temperature in POC made from banana peels was obtained during the initial fermentation time of 33 oC and the lowest temperature was obtained during the 3-day fermentation time of 25 oC, while in POC made from pineapple peel, the highest temperature was obtained during the initial fermentation time. of 33.5 oC and the lowest temperature was obtained during the 9-day fermentation time of 26 oC. The initial pH value for POC made from banana peels is 5 and the final pH is 4. While for POC pineapple peel, the initial pH value is 3 and the final pH is 4. For the C-Organic content in the initial POC peel the results are 0.095% and final C-Organic content of 0.021%. Meanwhile, the initial C-Organic content in the POC of pineapple peel was 0.037% and the final C-Organic content was 0.013%. The final value of the pH parameter is in accordance with the quality standard, which is 4-9 for pH, while the final value of the C-Organic parameter is not in accordance with the quality standard where the C-Organic content according to the quality standard is a minimum of 10%.

ENVIRONMENTAL SAFETY OF THE TECHNOLOGY OF HANDLING DIGESTATE OF DIFFERENT GENESIS

In the modern world, biogas technology is gaining momentum as an ecological alternative to the production of biofertilizer after anaerobic fermentation of various types of waste. Due to the large amount of organic, nutrient and biologically active substances, biogas digestates are often applied directly to the soil as an organic fertilizer to improve soil quality and increase yield. The purpose of the article is to determine the ecological safety of the digestate obtained after anaerobic fermentation of chicken litter and sewage sludge, as part of a biocomposite for soil purification from heavy metals. The methodological basis of this study are experiments on the phytotoxicity of digestate samples based on the results of the germination of pepper seeds in Petri dishes using aqueous solutions of untreated digestate and digestate treated with phosphogypsum. The expediency of choosing a phosphogypsum treatment method was due not only to the possibility of reducing the presence of pathogens in digestates, but also to obtain a biocomposite capable of adsorbing harmful elements from the soil and feeding it with necessary substances. Using the germination index, the level of phytotoxicity of digestate based on various organic wastes was assessed, the effectiveness of the use of digestate as a biological fertilizer was substantiated. It was determined that digestate based on sewage sludge became an ecologically safe substrate for the germination of pepper seeds. Digestate from chicken litter treated with phosphogypsum on the 20th day of anaerobic fermentation showed a phytotoxic effect on pepper seeds. Indicators of the germination index increased on the 30th day of anaerobic fermentation, which indicates a decrease in the toxicity of the material after the end of the anaerobic fermentation process. In general, a germination index higher than 50% was observed in all samples of untreated digestate and a greater number of samples of treated digestate for both substrates. The article provides recommendations for evaluating the maturity of digestate using the seed germination index as a quick indicator for determining the phytotoxicity of substrates and, accordingly, the level of environmental safety of the material for soil and plants.

Effects of Different Organic Fertilizer Substitutions for Chemical Nitrogen Fertilizer on Soil Fertility and Nitrogen Use Efficiency of Foxtail Millet

Conventional fertilizer management can destroy the structure of soil. Replacing chemical fertilizers with organic fertilizers can improve soil quality and nitrogen use efficiency. We aimed to study the effects of organic fertilizer substitutions for chemical nitrogen fertilizer on soil fertility and nitrogen use efficiency in order to clarify the effectiveness of the available nutrient management measures in improving soil quality and increasing foxtail millet yield. A field experiment was carried out over two consecutive years, and a total of six treatments were set up: no fertilizer (CK), chemical nitrogen fertilizer alone (N), the substitution of 25% of chemical nitrogen fertilizer with bio-organic fertilizer (N25A1), the substitution of 25% of chemical nitrogen fertilizer with fermented mealworm manure (N25B1), the substitution of 50% of chemical nitrogen fertilizer with bio-organic fertilizer (N50A2), and the substitution of 50% of chemical nitrogen fertilizer with fermented mealworm manure (N50B2). The results of this study show the following: (1) Compared with chemical nitrogen fertilizer, the substitution of organic fertilizer for nitrogen fertilizer reduced the bulk density and solid phase of the soil, and it increased the total porosity, water content, liquid phase, and gas phase of the soil. (2) Compared with nitrogen fertilizer, the use of an organic fertilizer increased the contents of nitrate nitrogen, ammonium nitrogen, and total nitrogen in the soil by 13.59~52.56%, 4.47~18.27%, and 4.40~12.09%, respectively. The content of alkaline nitrogen increased by 1.70~32.37%, and the contents of soil available potassium, available phosphorus, and organic matter also increased. (3) The activities of sucrase, urease, glutaminase, and asparaginase were improved by replacing chemical nitrogen fertilizer with organic fertilizer. The N25 treatments performed better than the N50 treatments, and fermented mealworm manure performed better than biological organic fertilizer. (4) A moderate application of organic fertilizer (N25) can increase the grain yield, ear weight, grain weight, and 1000-grain weight of foxtail millet, whereas excessive application of organic fertilizer (N50) can reduce foxtail millet yield. (5) Replacing chemical nitrogen fertilizer with organic fertilizer can improve the agronomic use efficiency, physiological efficiency, biased productivity, harvest index, and apparent use efficiency of nitrogen fertilizer. In this study, the substitution of 25% of chemical nitrogen fertilizer with fermented mealworm manure was the best combination for restoring crop productivity and soil quality.

The effect of mycorrhizal biofertilizer with the addition of rice washing water and eggshells on the growth of cayenne pepper plant (Capsicum frutescens L.)

Cayenne pepper is a leading horticultural commodity in Indonesia. The need for cayenne pepper is constantly increasing, but it is not balanced with its production because there are obstacles, especially in areas that are less fertile or have low nutrients. This study aims to find out the effect of applying mycorrhizal biological fertilizer by adding rice washing water and eggshells on the growth of cayenne pepper plants. This study used the Complete Randomized Design method. The data were analyzed using One Way Anova (significant level of 5%) and an alternative test Kruskal-Wallis H. The results showed mycorrhizal biological fertilizer 5 gr + rice washing water 200 ml and eggshells 20 gr optimally affecting the number of leaves, branches, and roots, dry weight of the crown. Mycorrhizal biofertilizer 10 gr + rice washing water 150 ml and eggshell 15 gr have an optimal effect on wet weight of the crown and the roots. Mycorrhizal biofertilizer 15 gr + rice washing water 200 ml and eggshell 20 gr have an optimal effect on root length. Mycorrhizal biofertilizer 2 gr + rice washing water 150 ml and eggshell 15 gr have an optimal effect on dry weight of roots.

Co-inoculation of fungi and desert cyanobacteria facilitates biological soil crust formation and soil fertility.

The inoculation of cyanobacteria for enriching soil nutrients and forming biological soil crusts (BSCs) is considered an effective means to restore degraded soil. However, there are limited studies on the application of co-inoculation of fungi and cyanobacteria for degraded soil remediation. In this study, a high exopolysaccharide-secreting fungi Zh2 was isolated from lichen BSCs in Hobq Desert, and co-inoculated with a cyanobacterial strain identified as Phormidium tenue in different proportions to form BSCs on sand during a 35 days incubation period. Results revealed significant differences in crust biomass and soil properties among crusts with different cyanobacterial/fungal inoculation ratios. Microbial biomass, soil nutrient content and enzyme activities in crusts co-inoculated with cyanobacteria and fungi were higher than those inoculated with cyanobacteria and fungi alone. The inoculation of cyanobacteria contributed to the fulvic-like accumulation, and the inoculated fungi significantly increased the humic-like content and soil humification. Redundancy analysis showed that the inoculation of cyanobacteria was positively correlated with the activities of urease and phosphatase, and the content of fulvic-like. Meanwhile, the inoculation of fungi was positively correlated with the contents of total carbon, total nitrogen and humic-like, the activities of catalase and sucrase. Cyanobacteria and fungi play distinct roles in improving soil fertility and accumulating dissolved organic matter. This study provides new insights into the effects of cyanobacteria and fungi inoculations on the formation and development of cyanobacterial-fungus complex crusts, offering a novel method for accelerating induced crust formation on the surface of sand.

Phosphorus Dynamics in Stressed Soil Systems: Is There a Chemical and Biological Compensating Effect?

Here, we hypothesized the occurrence of a compensatory relationship between the application of P and different microbial communities in the soil, specifically in relation to the chemical and biological effects in the soil–plant–microorganisms’ interaction. We aimed to evaluate the plant–microbiota responses in plants grown in soils hosting distinct microbial communities and rates of P availability. Two experiments were carried out in a greenhouse. The first experiment evaluated four manipulated soil microbiome compositions, four P rates, and two plant species. Manipulated soil systems were obtained by the following: (i) autoclaving soil for 1 h at 121 °C (AS); (ii) inoculating AS with soil suspension dilution (AS + 10−3); (iii) heating natural soil at 80 °C for 1 h (NH80); or (iv) using natural soil (NS) without manipulation. The P rates added were 0, 20, 40, and 60 mg kg−1, and the two plant species tested were grass (brachiaria) and leguminous (crotalaria). Inorganic labile P (PAER), microbial P (PMIC), acid phosphatase activity (APASE), and shoot P uptake (PUPT) were assessed for each system. Brachiaria presented a compensatory effect for PUPT, whereby the addition of P under conditions of low microbial community enhanced P absorption capacity from the soil. However, in a system characterized by low P input, the increase in the soil biodiversity was insufficient to enhance brachiaria PUPT. Likewise, crotalaria showed a higher PUPT under high P application and low microbial community. The second experiment used three manipulated microbiome compositions: AS + 10−3; NH80; and NS and three P rates added: 0, 20, and 40 mg kg−1. In addition, two treatments were set: without and with mycorrhiza inoculation. Brachiaria showed an increase in the PUPT under low microbial communities (AS + 10−3; NH80) with P addition (20 and 40 mg kg−1 of P), but no mycorrhization was observed. In the undisturbed microbial community (NS), under no P input (0 mg kg−1 of P), brachiaria showed low mycorrhization and low PUPT. Finally, NS and the recommended P input (40 mg kg−1 of P) represented a balance between chemical and biological fertility, promoting the equilibrium between mycorrhization and PUPT.

Using soil amendments and mycorrhiza to improve chemical properties of degraded calcareous soil and yield of sorghum in dryland

Optimized use of calcareous soil in dryland areas needs to begin with rehabilitation efforts using soil amendments, including organic fertilizer and biochar. This study sought to determine whether kinds of soil amendments and mycorrhizal biofertilizers may enhance the chemical quality of calcareous soils and increase the yield of sorghum on dry land. The study was conducted at the experimental garden of the Agricultural Extension Center located in Oelnasi Village from April to August of 2023. Two criteria included in the study were the kind of soil amendment and mycorrhizal biological fertilizer, both of which were arranged in a randomized block design. The parameters observed were soil chemical properties, plant N and P nutrient uptake, and sorghum yield. The research results showed that the application of three types of soil amendments (P1 = cow dung, P2 = rice straw compost, and P3 = corncob biochar) improved the chemical quality of calcareous soil. This application of corncob biochar could significantly reduce soil pH from 7.85 (slightly alkaline) to 7.19 (neutral) and increase soil organic C to 2.55% C, followed by treatment with cow dung and rice straw compost. Other soil chemical properties, i.e., N, P, K, and soil CEC, also improved, which differed from the control treatment. The mycorrhizal biofertilizer provided could also improve the chemical properties of calcareous soil. Providing mycorrhizal biofertilizer could increase the N and P nutrient uptake of sorghum plants by 3.79% dry weight-1 and 2.18% dry weight-1, respectively, as well as increased sorghum yields, respectively by 4.04 t ha-1, 3.97 t ha-1 and 3.87 t ha-1 dry beans, higher than the control which only achieved 2.32 t ha-1 dry beans.

Effect of Plant Growth-Promoting Bacteria (PGPB) on the Development of Pea crop (Pisum sativum L.)

Microorganisms are of great importance in agriculture in terms of plant nutrients by reducing the need for chemical fertilization. In recent years, plant growth-promoting bacteria (PGPB) have been widely used as biological fertilizers (BF) in agriculture. This study was conducted to determine the effect of plant growth-promoting bacteria on the development of pea plants. Firstly the phosphate solubilization and nitrogen fixation potentials of the bacteria used in this study were determined. In the study, the effects of 4 different combinations, F1 [(Rhizobium sp. (FR-13) and Pseudomonas alcaligenes (FDG121)], F2 [(Pseudomonas fluorescens biotype F (FDG-7), Rhizobium sp. (FR-18) and Bacillus-megaterium-GC subgroup B(FDG-134)], F3 [Arthrobacter oxydans (FDG-72), Bacillus-megaterium-GC subgroup B (FDG-146), Rhizobium sp. (FR-11)] and F4 [Acinetobacter genospecies 9 (FDG-116), Brevibacillus agri (FDG-118), Methylobacterium zatmanii (FDG-123) and Bacillus-megaterium-GC subgroup A (FDG-153)] were investigated. Formulations made with bacteria that were found to be the best in terms of the properties specified among these strains were tested against pea plants under greenhouse conditions and their effects on the plant's total fresh and dry weight were investigated. The study was set up to have 3 replications. As a result of the statistical analysis made with the data obtained, the formulations used compared to the control; F2, F3 and F1 applications were important in total fresh weight, respectively, and F2 and F3 applications were important in total dry weight. As a result, these 3 formulations are especially effective on the yield of pea plants and can be used as potential biofertilizers.

Effect of Paitan Compost Fertilizer and Corn Rooting Rhizobakteri on the Growth and Yield of Glutinous Corn (Zea mays L. ceratina)

Glutinous rice corn crops in Java show low productivity despite their potential. Agricultural land issues in Indonesia, such as soil fertility and excessive use of inorganic fertilizers, persist. Tithonia diversifolia plants are utilized for composting to address these concerns. Additionally, corn root microorganisms act as biological fertilizer, enhancing plant growth. This study aims to investigate the interaction between Tithonia compost dosage and corn root Rhizobacteria on glutinous corn growth and yield. Conducted in two locations—laboratory for Rhizobacteria isolates and field for composting and planting—the research employed a Divided Plot Design with 36 treatment combinations. Observations included plant height, stem diameter, leaf area, cob count, cob diameter, cob weight, and cob length. Results indicate interaction effects between Rhizobacteria and compost dosage on leaf area growth at 28 days post-planting. Additionally, there's an impact on stem blight intensity at 42 days post-planting. Rhizobacteria dosage didn't significantly affect plant growth or cob yield parameters. However, paitan compost dosage influenced plant height, stem diameter, and cob count, with the best response seen at 14 tons/ha dosage.

Multiple omics revealed the growth-promoting mechanism of Bacillus velezensis strains on ramie.

Beneficial bacteria that promote plant growth can shield plants from negative effects. Yet, the specific biological processes that drive the relationships between soil microbes and plant metabolism are still not fully understood. To investigate this further, we utilized a combination of microbiology and non-targeted metabolomics techniques to analyze the impact of plant growth-promoting bacteria on both the soil microbial communities and the metabolic functions within ramie (Boehmeria nivea) tissues. The findings indicated that the yield and traits of ramie plants are enhanced after treatment with Bacillus velezensis (B. velezensis). These B. velezensis strains exhibit a range of plant growth-promoting properties, including phosphate solubilization and ammonia production. Furthermore, strain YS1 also demonstrates characteristics of IAA production. The presence of B. velezensis resulted in a decrease in soil bacteria diversity, resulting in significant changes in the overall structure and composition of soil bacteria communities. Metabolomics showed that B. velezensis significantly altered the ramie metabolite spectrum, and the differential metabolites were notably enriched (P < 0.05) in five main metabolic pathways: lipid metabolism, nucleotide metabolism, amino acid metabolism, plant secondary metabolites biosynthesis, and plant hormones biosynthesis. Seven common differential metabolites were identified. Correlation analysis showed that the microorganisms were closely related to metabolite accumulation and yield index. In the B. velezensis YS1 and B. velezensis Y4-6-1 treatment groups, the relative abundances of BIrii41 and Bauldia were significantly positively correlated with sphingosine, 9,10,13-TriHOME, fresh weight, and root weight, indicating that these microorganisms regulate the formation of various metabolites, promoting the growth and development of ramie. Conclusively, B. velezensis (particularly YS1) played an important role in regulating soil microbial structure and promoting plant metabolism, growth, and development. The application of the four types of bacteria in promoting ramie growth provides a good basis for future application of biological fertilizers and bio-accelerators.