Potassium Release Research Articles

PATTERN OF POTASSIUM RELEASE FROM SLOW RELEASE FERTILIZER POTASSIUM SULFATE-BENTONITE FERTILIZER

Potassium is a macro nutrient element that is needed by plants. Potassium plays a role in plant metabolism, maintains turgor, and forms stronger stems. Sadly. Potassium is easily lost through washing because it is easily soluble in water. This is what triggers plants to often experience a lack of potassium. Efficiency in the use of potassium fertilizers can be increased through the formulation of fertilizers made in the form of slow release (Slow Release Fertilizer), namely by controlling the solubility of the substance in water through fertilizer coating. The purpose of this study was to determine the potassium content obtained, the largest mass of SRF fertilizer, and the pattern of potassium release in the soil after being bound by acid-activated bentonite in the manufacture of potassium sulfate SRF. Coating of potassium sulfate with bentonite was carried out with a mass of 10 bentonite; 20; 30; 40; and 50 grams with a mass of 10 grams of potassium sulfate. Total potassium levels were analyzed by atomic absorption spectrophotometer. The results of the analysis of potassium levels obtained the levels of each SRF fertilizer with the code SRF 10: SRF 20: SRF 30: SRF 0; and SRF so respectively 4.41: 5.49: 6.06: 6.54; and 7.01 mg/g with the maximum concentration obtained from SRF sa fertilizer. Furthermore, the potassium release test was carried out using the percolation method with distilled water for potassium sulfate-bentonite SRF fertilizer with a ratio of 10:50. release test using time variation every 1 week period for 1 month. As a result, the average potassium level was obtained, namely 11.51; 38.33; 51.37; and 72.24% w/b. Based on the results of this release test it is known that potassium. experience a slow release pattern in the soil.

A rare case of tumour lysis syndrome in multiple myeloma

Tumour lysis syndrome (TLS) is a serious life-threatening complication of cancer chemotherapy which is a constellation of metabolic disturbances that typically occurs during therapy of bulky, rapidly proliferative tumours. TLS is an oncological emergency that causes a significant release of phosphate, potassium, uric acid, and nucleic acids into the blood stream. Incidence of TLS in multiple myeloma is rare. Here we present a case of multiple myeloma who later developed tumour lysis syndrome in its due course which was rare. A 67-year-old male was diagnosed with Multiple myeloma on the basis of M spike, osteolytic lesions and bone marrow analysis. First cycle of chemotherapy with lenalidomide, bortezomib and denosumab was initiated. During the course of follow up he presented to our casualty with complaints of chills and rigor. Based on the biochemical abnormalities a diagnosis of tumour lysis syndrome was made. He received I.V fluids, anti-hyperkalemic measures, allopurinol. He had neutropenic sepsis and went into septic shock and died after multiple resuscitative efforts.

Integrated interaction between Nano, conventional potassium fertilizer and Zeolite on kinetic K-release from calcareous soil

Calcareous soil suffers from deficiency in available of potassium due to its high contain of CaCO3. So, it is important to increase the availability of potassium. Potassium release rate constant is an important indicator for the ability of soil to supply potassium. A field experiments in sulaimani governorate was conducted to evaluate the effect of soil amendment with natural zeolite at rate of (0 and 2 t ha-1), three levels of Nano potassium fertilizer (0, 5 and 10 kg ha-1), three levels of conventional fertilizer K2SO4 (0, 100 and 200 kg ha-1 K2O) and their interactions on kinetic of potassium release within 55 days. Results revealed that there was significant effect of application Zeolite on cumulative K-release that increased by 13.27 % relative to the control treatment. the application Nano, conventional K fertilizer and their interaction with zeolite at level of 5 kg ha-1 Nano, 200 kg ha-1 K2O and 10 kg ha-1 Nano + 100 kg ha-1 K2O amendment with 2 t ha-1 zeolites increased the cumulative K-release from 33.55 to 35.35 and 42.45 mg kg-1 respectively as a compared with control (24.00 mg kg-1). Kinetic data were best described by parabolic diffusion, power function and Elovich models. The cumulative K-release rate constants for parabolic models indicated that all types of fertilizers applied to soil gave high and significant increase in rate of K release compared to the control treatment.

Release of phosphorus from thermal conversion of phosphorus-rich biomass chars – Evidence for carbothermic reduction of phosphates

Biomass can be used to generate heat, power, or biofuels in thermal conversion processes such as combustion, gasification and pyrolysis. However, some types of biomass contain high levels of phosphorus, which can be released to the gas phase and cause operational or environmental problems. The mechanism(s) responsible for phosphorus release has not been convincingly established. Understanding the high-temperature phosphorus chemistry is also important in order to enable efficient recovery of phosphorus in residues from thermal conversion of biomass. In this work, the release of phosphorus from wheat bran char and sunflower seed char in different gas environments (100 % N2, 1–20 % O2, and 10 % CO2) and temperatures (900–1100 °C) was studied. The chars were converted in a horizontal tube reactor and characterized using ICP-OES, XRD, SEM-EDS, and 31P NMR. The release of ash-forming elements was determined using ICP-OES analysis of the char and sample residues, whereas the release of carbon was determined using CO and CO2 gas analysis. In both chars, phosphorus was present primarily together with potassium and magnesium, mainly as pyrophosphates in the wheat bran char, and largely as orthophosphates in the sunflower seed char. For wheat bran char, the release of phosphorus increased from 27 % at 900 °C to 71 % at 1100 °C in N2, whereas the release was at least 20 % lower in the oxidizing atmospheres (1–20 % O2, or 10 % CO2). The sunflower seed char reached a maximum release of 55 % at 1100 °C in N2. For wheat bran char, the molar ratio of released carbon/phosphorus was close to 2.5, which fits well with the theoretical value for carbothermic reduction of phosphates (P2O5(s, l) + 5C(s) → P2(g) + 5CO(g)). At 1100 °C, in N2, the release of phosphorus, potassium and sodium occurred mainly during the first 10 min. It was shown that KMgPO4, used as a model compound, could be reduced by carbon starting from 950 °C, but that some of the phosphorus remained in the condensed phase. The work provides a better understanding of phosphorus release and presents evidence showing that carbothermic reduction reactions can be an important phosphorus release mechanism for seed- and grain-based biomass char.

Temporal Dynamics of Potassium Release from Waste Mica as Influenced by Potassium Mobilizing Bacteria

Potassium mobilizing bacteria (KMB) strains have been isolated from waste mica mines in the Giridih district of Jharkhand, India, using Alexandrov media. These isolates were evaluated for their potential to dissolve water soluble-K from waste mica (muscovite and biotite). Identity was confirmed based on sequencing of 16S rDNA region of those isolates showing promising water soluble-K dissolving capacity. Strains were found to be different isolates of Bacillus cereus, two unconfirmed Bacillus species (strain- 6SB1 and GG6), and one each of B. velezensis and Paraburkholderia kururiensis. Finally, the four most efficient KMB were selected based on their K-mobilizing capability. The K5B (B. cereus) isolate showed the highest K-solubilising capacity in both muscovite and biotite enriched medium. Soil incubation study was conducted using soils of Giridih (Alfisol) with three gradient concentrations of both waste mica tailings and K-solubilising capacity of four KMB isolates (B. cereus, strain- K5B, K6, K15; and Bacillus sp. GG6- K12) were measured at 4, 7, 14 and 21 days intervals. The K release dynamics in incubated soils indicated that potassium was released from both types of micas to significantly higher water-soluble K (WS-K) and exchangeable K (Ex-K) pools due to the inoculation of KMB isolates. Apart from potassium solubilization, B. cereus strain K5B and Bacillus sp. GG6 showed capabilities to produce indole acetic acid (IAA) and gibberellic acid (GA). These results suggested that a combination of KMB strain and powdered mica tailings could be a suitable alternative to commercial chemical fertilizers and maintain soil nutrient status for plant uptake.

Numerical Study and Experimental Verification of Biomass Conversion and Potassium Release in a 140 kW Entrained Flow Gasifier.

In this study, a Eulerian-Lagrangian model is used to study biomass gasification and release of potassium species in a 140 kW atmospheric entrained flow gasifier (EFG). Experimental measurements of water concentration and temperature inside the reactor, together with the gas composition at the gasifier outlet, are used to validate the model. For the first time, a detailed K-release model is used to predict the concentrations of gas-phase K species inside the gasifier, and the results are compared with experimental measurements from an optical port in the EFG. The prediction errors for atomic potassium (K), potassium chloride (KCl), potassium hydroxide (KOH), and total potassium are 1.4%, 9.8%, 5.5%, and 5.7%, respectively, which are within the uncertainty limits of the measurements. The numerical model is used to identify and study the main phenomena that occur in different zones of the gasifier. Five zones are identified in which drying, pyrolysis, combustion, recirculation, and gasification are active. The model was then used to study the transformation and release of different K species from biomass particles. It was found that, for the forest residue fuel that was used in the present study, the organic part of K is released at the shortest residence time, followed by the release of inorganic K at higher residence times. The release of inorganic salts starts by evaporation of KCl and continues by dissociation of K2CO3 and K2SO4, which forms gas-phase KOH. The major fraction of K is released around the combustion zone (around 0.7-1.3 m downstream of the inlet) due to the high H2O concentration and temperature. These conditions lead to rapid dissociation of K2CO3 and K2SO4, which increases the total K concentration from 336 to 510 ppm in the combustion zone. The dissociation of the inorganic salts and KOH formation continues in the gasification zone at a lower rate; hence, the total K concentration slowly increases from 510 ppm at 1.3 m to 561 ppm at the outlet.

The Effect of Wetting and Drying Cycles on Potassium Release in Three Soil Orders

The Effect of Wetting and Drying Cycles on Potassium Release in Three Soil Orders

Potassium Fixation and Release Characteristics in Acidic Soils of Three Different Soil Orders of West Bengal, India

Potassium Fixation and Release Characteristics in Acidic Soils of Three Different Soil Orders of West Bengal, India

Phonolite associated with organic compound and potassium solubilizing bacteria in tomato cultivation

The use of rock dust in Brazil has been studied and encouraged to reduce the Brazilian dependence on the foreign market for chemical fertilizers and as an alternative to organic agriculture. The objective of this research was to evaluate the effects of using phonolite rock powder and organic compound, associated with inoculation with the potassium solubilizing bacteria (KSB) of the genus Burkholderia on the chemical characteristics of the soil, macro and micronutrients in the aerial part, and tomato productivity. The experiment was installed in pots in a greenhouse, using a randomized block design in a 5 × 2 factorial arrangement, representing five doses of phonolite added in an organic compound, with the presence or absence of inoculation with the strain 100-13. The nutrient contents in the soil and the aerial part and the production of tomato were evaluated. Differences were observed between the doses of the organic compound and the phonolite associated with the inoculation. The treatments containing the highest doses of an organic compound provided better levels of nutrients in the soil and the aerial part, and in the tomato productivity. The inoculation with the bacterial strain improved the release of potassium from the powder of the phonolite rock.

Role of Aminated Derivatives of Natural Gum in Release Modulating Matrix System of Losartan Potassium

Objective: The investigation aimed to synthesize amino derivatives of various natural gums like Xanthan gum and Tamarind gum for using them as a release modulating polymer in the formulation of the hydrophilic matrix system of losartan potassium and to find the best amongst them. Developing oral sustained release matrix tablets for a drug with a constant release rate has always been a challenge to the pharmaceutical technologist. 
 Materials and Methods: Release modulating hydrophilic matrix tablets of losartan potassium were prepared by wet granulation method. A total number of 6 formulations of release modulating hydrophilic matrix tablets of losartan potassium were prepared using different polymeric ratios of Carbopol 934, aminated Tamarind gum and aminated Xanthan gum based on preliminary trial bathes. The formulated tablets were evaluated for both pre-compression and post-compression evaluation studies. 
 Results: Based on in vitro drug release study the effective formulations AXG 3 are shows a maximum similar release profile to other remains formulations with a theoretical drug release profile of losartan potassium for sustained release. Finally optimized formulation AXG 3 containing carbopol 934 (60 mg), aminated xanthan gum (40 mg), MCC (190 mg) and magnesium stearate (10 mg) showed 100±0.024 % drug release in 12 hr which is acceptable with theoretical drug release of losartan potassium for sustain release dose. Conclusion: Aminated derivatives of xanthan gum and Tamarind gum extend the drug release for 12 hr. Based on in vitro drug release studies of formulations, we concluded that the alteration in the concentration of carbopol 934 with an aminated derivative of xanthan gum in sustain release formulation development was more effective and economical.

A multi-step predictive model for the release and transformation of K-Cl-S-containing species from biomass

The release of inorganic elements, especially K, Cl, and S, can cause severe damage to biomass conversion devices, such as slagging, fouling, or corrosion. A predictive model for the release of K-Cl-S elements can be used to enhance the design and operating conditions of biomass conversion devices. In this study, a detailed model is developed that includes 12 solid species and 13 reactions, which can represent the main pathways of the release of K-Cl-S from the particle. The model is coupled to a particle model to predict the release of potassium from different types of biomass at various operating conditions. First, the types and solubility of the potassium after pyrolysis and combustion at different temperatures are compared with the experimental data from the literature. The model predictions of the H2O-soluble, NH4AC-soluble, stable, and total potassium are comparable to the experimental data. Second, the K, Cl, and S in two types of biomass with high and low Si content are studied and compared with the experimental data. The model is used to explain different stages of potassium, sulfur, and chlorine release, which were observed in the experiments. Finally, the concentration of gas-phase potassium-containing species, i.e., atomic K, KCl, and KOH, downstream of burning biomass particles at different temperatures are investigated and compared with experimental measurement. The model can capture the release behavior of these species at different temperatures with good accuracy. The model results are summarized to create a clearer picture of the pathways of K-Cl-S-release from biomass and their interactions with other ash elements.

Sugarcane bagasse derived phosphorylated cellulose as substrates for potassium release induced by phosphates surface and drying methods

Encapsulation and controlled release of potassium by phosphorylated cellulose (P-cell) was systematically demonstrated by drying of aqueous P-cell suspensions with potassium chloride (KCl) in varied stoichiometric K+/Cell-O-HPO3- ratios of 1:1, 2:1, and 4:1, and dried into powder-like fibrous fluffs, paper-like films, and three-dimensional porous structures by spray-, oven-, and freeze-drying. Cellulose isolated from sugarcane bagasse as agricultural waste was optimally phosphorylated at 1:0.5:2 anhydroglucose (AHG)/(NH4)2HPO4/CO(NH2)2 as 14.6 µm wide, ca. 366 µm long, highly crystalline (72%) microfibers with 2.4 mmol g−1 charge. Oven drying led to more crystalline (73%) and thermally stable (252.1 °C) films than spray-dried powders (67%, 250.5 °C) and freeze-dried porous bulk (71%, 249.8 °C). The release of highly water-soluble KCl from these three P-cell substrates was highest from the fibrous (90.4–97.3%), three-dimensional porous structure solids (73.5–81.7%), then films (60.4–74.5%), thus could be tuned by varying the anionic/cationic loadings along with drying methods.

In-situ measurement of combustion characteristics and potassium release concentration during torrefied biomass burning based on spontaneous emission spectroscopy

The orthogonal experiment designed in this paper investigated the effect of changes in experimental parameters such as biomass species, torrefaction temperature, torrefaction time, torrefaction oxygen concentration on the physicochemical properties and combustion characteristics of the torrefaction products. Two optical fiber spectrometers were used to capture the spontaneous emission spectra of the combustion flame of compressed pellets of torrefied biomass, and the in-situ measurement of pellet combustion temperature and K release concentration at high heating rate was realized by multi-spectral analysis algorithm. The experimental results indicate that for biomass, torrefaction will lead to a decrease of volatile and moisture content and an increase of fixed carbon and ash content in components, a decrease of O and H and an increase of C content in elements, a certain loss of biomass quality, an increase of high heat value, and each indicator move closer to coal. The effects of various experimental parameters on the volatile content, mass yield, high heat value increase rate and energy yield in biomass torrefaction products have similar laws, i.e., biomass species / torrefaction oxygen concentration > torrefaction temperature > torrefaction time. The mild torrefaction product pellets have a shorter ignition delay, increased volatile combustion flame height and peak temperature, longer volatile and char combustion duration, but lower peak char combustion temperature, among which the selected torrefaction products of rice straw and pine wood showed an increase in peak temperature of 0.56 % (11 K) and 0.61 % (12 K) for the volatile stage respectively, and a decrease of and 1.29 % (20 K) and 1.29 % (21 K) for the char stage respectively. In addition, the peak K release concentration during combustion of the mild torrefaction product pellets was reduced, among which the peak K release concentrations during the volatile and char stage were reduced by 43.22 % (3.89 ppm) and 52.93 % (51.55 ppm) of the rice straw torrefaction product respectively, and by 73.14 % (1.28 ppm) and 62.08 % (15.01 ppm) for the pine wood torrefaction product respectively. Biomass torrefaction products have fuel properties closer to coal, less K released from the combustion process, which have the potential to become an alternative to coal.

Physicochemical surrogates for in vitro toxicity assessment of liposomal amphotericin B

Pharmaceutical toxicity evaluations often use in vitro systems involving primary cells, cell lines or red blood cells (RBCs). Cell-based analyses (‘bioassays’) can be cumbersome and typically rely on hard-to-standardize biological materials. Amphotericin B (AmB) toxicity evaluations are primarily based on potassium release from RBCs and share these limitations. This study evaluates the potential substitution of two physicochemical AmB toxicity approaches for the bioassay: Ultraviolet–visible spectroscopy (UV–vis) and in vitro drug release kinetics. UV–vis spectral analyses indicated that liposomal AmB’s (L-AmB) main peak position (λmax) and peak ratio (OD346/OD322) are potential toxicity surrogates. Similarly, two first-order release parameters derived from USP-4 in vitro drug release analyses also provided linear relationships with toxicity. These were the initial, overall drug release rate and the ratio of loose to tight AmB pools. Positive slopes and high correlation coefficients (R2 > 0.9) characterized all interrelations between physicochemical parameters and toxicity. These tests converted the manufacturing variables' nonlinear (i.e., curvilinear) relationships with in vitro toxicity to linear responses. Three different toxicity attenuation approaches (2 manufacturing, 1 formulation), covering formulation composition and process aspects, support this approach’s universality. These data suggest that one or more spectral and kinetic physicochemical tests can be surrogates for L-AmB in vitro toxicity testing.

Reinventing the Penumbra - the Emerging Clockwork of a Multi-modal Mechanistic Paradigm.

The concept of the ischemic penumbra was originally defined as the area around a necrotic stroke core and seen as the tissue at imminent risk of further damage. Today, the penumbra is generally considered as time-sensitive hypoperfused brain tissue with decreased oxygen and glucose availability, salvageable tissue as treated by intervention, and the potential target for neuroprotection in focal stroke. The original concept entailed electrical failure and potassium release but one short of neuronal cell death and was based on experimental stroke models, later confirmed in clinical imaging studies. However, even though the basic mechanisms have translated well, conferring brain protection, and improving neurological outcome after stroke based on the pathophysiological mechanisms in the penumbra has yet to be achieved.Recent findings shape the modern understanding of the penumbra revealing a plethora of molecular and cellular pathophysiological mechanisms. We now propose a new model of the penumbra, one which we hope will lay the foundation for future translational success. We focus on the availability of glucose, the brain's central source of energy, and bioenergetic failure as core pathophysiological concepts. We discuss the relation of mitochondrial function in different cell types to bioenergetics and apoptotic cell death mechanisms, autophagy, and neuroinflammation, to glucose metabolism in what is a dynamic ischemic penumbra.

NUTRIENT DYNAMICS IN SOIL ASSOCIATED WITH LEAF LITTER OF Shorea robusta Gaertn. f. IN MADHUPUR SAL FOREST OF BANGLADESH

Litter plays an important role in nutrient cycling in forest ecosystem. Nutrients are released from litter through leaching, and decomposition process and readily available nutrients are obtained through leaching process. Shorea robusta forest is a tropical deciduous forest and shed their leaves during the dry season. In the vicinity, poor people usually collect this litter from the forest to meet household demand for fuel. Thus, a considerable amount of nutrients is lost from this system.However, some nutrients from those leaves is possible to harvest through leaching technique before use as fuel. Therefore, to quantify this nutrient Leaf litter production and leaf litter standing crop were estimated in the Modhupur Sal forest. In addition, mass loss and nutrients (nitrogen, potassium and phosphorus) release through leaching were observed over 192 hours through leaching process in the laboratory. Mean leaf litter production was found 12.94 ± 0.65 g/m2/day during the litter shedding period was estimated to and the mean leaf litter standing crop was found 89.20 ± 9.77g/m2. About 10% of initial mass was lost after 48 hours of leaching process. Moreover, initial concentration of nitrogen and phosphorus was sharply decreased to 65 µg/g and 42 µg/g respectively after 24 hours and initial concentration (38 µg/g) of potassium was sharply decreased to 5 µg/g after 12 hours. About 25%, 45% and 92% of initial N, P and K content, respectively can be extracted through leaching process.

Nanoparticle Emulsions Enhance the Inhibition of NLRP3.

Antibacterial delivery emulsions are potential materials for treating bacterial infections. Few studies have focused on the role and mechanism of emulsions in inflammation relief. Therefore, based on our previous analysis, in which the novel and natural Pickering emulsions stabilized by antimicrobial peptide nanoparticles were prepared, the regulation effect of emulsion on inflammasome was explored in silico, in vitro and in vivo. Firstly, the interactions between inflammasome components and parasin I or Pickering emulsion were predicted by molecular docking. Then, the inflammasome stimulation by different doses of the emulsion was tested in RAW 264.7 and THP-1 cells. Finally, in Kunming mice with peritonitis, NLRP3 and IL-1β expression in the peritoneum were evaluated. The results showed that the Pickering emulsion could combine with ALK, casp-1, NEK7, or NLRP3 to affect the assembly of the NLRP3 and further relieve inflammation. LPNE showed a dose–dependent inhibition effect on the release of IL-1β and casp-1. With the concentration of parasin I increased from 1.5 mg/mL to 3 mg/mL, the LDH activity decreased in the chitosan peptide-embedded nanoparticles emulsion (CPENE) and lipid/peptide nanoparticles emulsion (LPNE) groups. However, from 1.5 to 6 mg/mL, LPNE had a dose–dependent effect on the release of casp-1. The CPENE and parasin I-conjugated chitosan nanoparticles emulsion (PCNE) may decrease the release of potassium and chloride ions. Therefore, it can be concluded that the LPNE may inhibit the activation of the inflammasome by decreasing LDH activity, potassium and chloride ions through binding with compositions of NLRP3.

Insight into KOH and KCl release behavior of burning wood and straw pellets using quantitative in situ optical measurements

Two-dimensional laser-induced photofragmentation fluorescence (LIPF) was employed to quantitatively visualize the potassium hydroxide (KOH) and potassium chloride (KCl) vapor in the plume above burning wood and straw pellets. In the LIPF measurement, two excitation lasers at 266 and 193 nm were adopted to discriminate KOH and KCl. Meanwhile, tunable diode laser absorption spectroscopy (TDLAS), laser-induced breakdown spectroscopy (LIBS) and two-color pyrometry were used to measure the atomic potassium concentration, total elemental potassium concentration and surface temperature of the burning pellets, respectively. The combustion environment had a temperature of 1550 K and an oxygen concentration of 4.6 vol.%. Two peaks were observed from the temporal potassium release profile of the burning wood, corresponding to the devolatilization and char oxidation stage, while only a single release peak was observed from the burning straw attributed to its high ash content. During the char oxidation and ash cooking stages, KOH was observed to be the dominant potassium species released from the wood, while only KCl was observed for the straw which had a high content of chlorine. About 45% of the total potassium in the wood samples and about 10% in the straw samples were measured to be released during the combustion process. The high content of silicon in the straw retained a considerable amount of potassium in the ash. The wood had the potassium release mainly in the char oxidation stage (∼53% of the total release), while the straw had the main release during the ash cooking stage (∼49% of the total release). During the char oxidation and ash cooking stages, about 32% of Cl was released from the straw pellets in KCl, while the other part of Cl was considered to be released during the devolatilization stage in other Cl species form, such as HCl.

Effect of Chromium Species and Plant Growth Promoting Microorganisms on Growth Parameters of Amaranthus gangeticus

In agricultural regions close to industrial areas, especially at the vicinity of tannery industry, chromium contamination poses a serious environmental risk. A pot experiment was carried out in the current study to assess the impact of hexavalent and trivalent chromium under the influence of microorganisms on Amaranthus gangeticus growth characteristics. Nine different concentrations of chromium (Cr) were used which consists of 0, 50, 100, 150, and 200 mg/kg Cr+6 as K2Cr2O7 and 50, 100, 150, and 200 mg/kg Cr+3 as KCr(SO4)2, in conjunction with four different levels of microorganisms, consisting of control, Azospirillum, Phosphate solublizing Bacteria (PSB), and Potassium Releasing Bacteria (KRB). The study revealed that when Cr concentrations increased, steady decline was observed in shoot, root length, leaf length, leaf breadth, number of leaves, and fresh weight. But when supplemented with KRB, the treatments had an ameliorative impact on chromium and, in comparison, enhanced the growth characteristics.

Potassium Source and Biofertilizer Influence K Release and Fruit Yield of Mango (Mangifera indica L.): A Three-Year Field Study in Sandy Soils

Arid degraded soils have a coarse texture and poor organic matter content, which reduces the activity of microorganisms and soil enzymes, and thus the soil quality, plant yield and quality decrease. Potassium solubilizing bacteria (KSB) have been suggested to increase the activity of soil enzymes and increase the release of potassium from natural K-feldspar in the arid degraded soil, and thus potentially reduce the rates of the application of chemical fertilizers. Field studies were conducted for three successive growing seasons in an organic farming system to investigate the effects of K-feldspar and KSB (Bacillus cereus) on K release, soil fertility, and fruit yield of mango plants (Mangifera indica L.). The maximum growth of mango plants was found in the treatments inoculated with KSB. KSB increased soil available N, P, K, and the activity of dehydrogenase and alkaline phosphatase enzymes by 10, 7, 18, 54, and 52%, respectively. KSB increased the fruit yield of mango by 23, 27, and 23% in the first, second, and third growing seasons, respectively. The partial (up to 50%) substitution of chemical K-fertilizer with K-feldspar gave fruit yield and quality very close to that fertilized with the full chemical K-fertilizer. The release rate of K (over all the treatments) varied between 0.18 and 0.64 mg kg−1 of soil per day. KSB significantly increased the K release rate. The application of chemical K-fertilizer gave the highest K release, while substitution with K-feldspar reduced the release of K. Natural K-feldspar contains 8.2% K but is poorly soluble when applied alone. KSB increased the soil quality parameters and enhanced the growth and quality of mango fruit. The fruit yield of mango, under KSB inoculation and fertilization with different K sources, ranged between 9.14 to 17.14 t ha−1. The replacement of 50% of chemical K-fertilizer with natural K-feldspar caused a decrease in the fruit yield by 17, 8, and 2.7% in the first, second, and third years, respectively. The substitution of chemical K-fertilizer with K-feldspar up to 50% with KSB is a good strategy to reduce the excessive use of chemical K-fertilizer. B. cereus and natural K-feldspar have the potential to improve soil health and mango plant productivity in low fertile arid soils.