Potassium Balance Research Articles

Determine the Balance of Nitrogen, Potassium, and Silicon Fertilization for the Control of Rice Tungro Disease Using Response Surface Methodology

This study evaluates the efficacy of combined N, K, and Si treatments to find the balance of these three elements for tungro disease control and rice grain production. The study was conducted in a pot under a glasshouse. These elements were chosen as several findings have indicated the positive benefits of nitrogen (N), potassium (K), and silicon (Si) fertilization on plant development, yield, and biotic stress relief. The methods used were central composite design and response surface methodology. Complete and balanced nutrition has always been the first line of defense for plants due to the direct involvement of mineral elements in plant protection. The results showed that rice tungro disease could be controlled with 138:42:62:200 (N:P2O5:K2O:Si). A high rate of nitrogen is needed to reduce disease development. The results on N may explain that not all conditions of rice plants are at risk with high N rates. Adding Si fertilizer contributes to plant defense mechanisms and plays a role in yield formation. In contrast, the balance of fertilizer for maximizing grain yield per plant was found to be not dependent on nitrogen but needed either low K (62 kg K2O/ha) or high K (80 kg K2O/ha) but with moderate Si (150 kg Si/ha). Prioritizing tungro disease control and adopting the rate of N:K2O:Si (138:62:200), it was found that there was a yield reduction of an average of 7.7%.

Consumption of a Branched-Chain Amino Acids-Containing Sports Beverage During 21 km of Running Reduces Dehydration, Lowers Muscle Damage, and Prevents a Decline in Lower Limb Strength

Objectives: The purpose of this study was to examine the acute effects of branched-chain amino acids (BCAAs)-containing electrolyte beverage (AE) on water–electrolyte balance, muscle damage, time to finish the final 5 km, and muscle strength compared to a standard commercially available carbohydrate–electrolyte sports beverage (CE), pure water (W), and no rehydration (N). Methods: Fourteen trained male participants (20 ± 2 years old) completed four randomized 21 km running trials. The participants were instructed to consume their drink (150 mL W, 150 mL CE, or 150 mL AE) or no rehydration (N) at 5 km, 10 km, and 15 km. Body mass and muscle strength were assessed, and blood samples were collected before and after exercise. Perceptual scales were administered during and after running. Blood electrolyte levels (sodium, potassium, and chloride) and creatine kinase (CK) concentration were analyzed. Results: The change in plasma volume with AE was significantly smaller than that with N (p < 0.05). Consuming AE maintained the best potassium balance (p < 0.05). Twenty-four hours after exercise, serum CK concentrations significantly elevated in N, W, and CE (p < 0.05), but did not reach statistical significance in the AE group (p > 0.05). Compared to N, consuming AE resulted in significantly less soreness 24 h after exercise (p < 0.05). There was no difference in time to finish the final 5 km (p > 0.05). Maximal voluntary isometric force output was significantly lower after exercise with N and W (p < 0.05) but not with CE or AE (p > 0.05). Conclusions: Consuming a BCAAs-containing sports beverage during a 21 km run can help reduce dehydration, maintain potassium balance, lower muscle damage, and prevent the decline in lower limb strength after 21 km running.

Effect of Different Irrigated Crop Successions on Soil Carbon and Nitrogen–Phosphorus–Potassium Budget Under Mediterranean Conditions

Sustainability in agroecosystems relies on the optimized use of resources to achieve consistent yields while maintaining or improving soil health. The monitoring of soil quality is crucial when changes from rainfall-fed to irrigated crop systems occur. The objective of this study was to assess the impact of different crop successions in the Mediterranean area under irrigation and different technical practices. The soil nitrogen–phosphorous–potassium (NPK) and soil organic carbon (SOC) balances were observed in four fields with irrigated annual crops in a two-year succession timeframe, namely, sunflower–maize (P1), sunflower–clover (P2), maize–sunflower (P3), and alfalfa–alfalfa (P4). The SOC and nutrient balance, integrating the total irrigation, mineral fertilizers, and exported yield, was calculated for each farm. Except for maize–sunflower succession (P3), all fields presented a negative SOC balance at the end of the two-year crop succession, indicating losses from 2.84 to 4.91 Mg SOC ha−1 y−1. While in N-fixing plants the soil N decreased, in the remaining crops a surplus was observed, possibly leading to future N losses. The continuous depletion of soil P revealed a potential underestimation of this nutrient. Soil K appears to be related to specific crop management practices, namely, crop residue incorporation after harvest. In annual irrigated crops under Mediterranean conditions, crop succession can induce soil fertility degradation if conservation practices are absent.

Sex differences in the adrenal circadian clock: A role for BMAL1 in the regulation of urinary aldosterone excretion and renal electrolyte balance in mice.

Brain and muscle ARNT-Like 1 (BMAL1) is a circadian clock transcription factor that regulates physiological functions. Male adrenal-specific Bmal1 (ASCre/+::Bmal1) KO mice displayed blunted serum corticosterone rhythms, altered blood pressure rhythm, and altered timing of eating, but there is a lack of knowledge in females. This study investigates the role of adrenal BMAL1 in renal electrolyte handling and urinary aldosterone levels in response to low salt in male and female mice. Mice were placed in metabolic cages to measure 12-hour urinary aldosterone after a standard diet and 7 days low salt diet, as well as daily body weight, 12-hour food and water intake, and renal sodium and potassium balance. Adrenal glands and kidneys were collected at ZT0 or ZT12 to measure expression of aldosterone synthesis genes and clock genes. Compared to littermate controls, ASCre/+::Bmal1 KO male and female mice displayed increased urinary aldosterone in response to a low salt diet, although mRNA expression of aldosterone synthesis genes was decreased. Timing of food intake was altered in ASCre/+::Bmal1 KO male and female mice, with a blunted night/day ratio. ASCre/+::Bmal1 KO female mice displayed decreases in renal sodium excretion in response to low salt, but both male and female KO mice had changes in sodium balance that were time-of-day-dependent. In addition, sex differences were found in adrenal and kidney clock gene expression. Notably, this study highlights sex differences in clock gene expression that could contribute to sex differences in physiological functions.

Subsoil testing required to detect the rundown of soil potassium to deficient levels for wheat production on loam-textured soils

Context Long-term negative potassium (K) balances in crop production have depleted soil K levels in Western Australia (WA). Previous research has focussed on sand-textured soils, but recently, monitoring of crops grown on loam-textured soils has shown deficient or marginal shoot K concentrations where Colwell K 0–10 cm is above current critical levels. Aims The aims were to examine whether grain yield responses to fertiliser K can be detected on loam-textured soils and if soil test calibration curves can be identified for these soils. Methods Eight field trials were conducted with wheat on loam-textured soils. The same experimental design was used at all sites; six levels of K applied at sowing, from 0 to 200 kg K ha−1 with one treatment including a split application. Soil and plant test calibration curves were modelled using measurements from the trials. Key results Grain yield responses of 0.69 to 1.37 t ha−1 to fertiliser K (P < 0.05) occurred in 4 of 8 trials. Relative yield was closely related to soil exchangeable K and the goodness of fit of the soil test calibration curves increased as the depth of sampling increased. The best soil test calibration curve was for sampling 0–40 cm. Conclusions This research confirms that on some loam-textured soils, yield loss is occurring to K deficiency if no K fertiliser is applied. Implications As soil K reserves are run down, soil sampling at 0–40 cm on loam-textured soils will provide the most accurate monitoring of soil K deficiency for wheat production.

Budgeting of Primary Nutrients in Soil under Rice-cowpea Cropping Sequences in Alfisols

A field experiment was undertaken at University of Agricultural Sciences, GKVK, Bengaluru, Karnataka, India to study the primary nutrients budgeting in rice-cowpea cropping system in an alfisols. Hybrid rice was tested under aerobic condition during Kharif 2015-16 and 2016-17 with 16 treatments replicated thrice in randomized block design. Notably maximum grain (62.98 q ha-1) and straw (85.26 q ha-1) yield of rice was registered in treatment, which received 100% STCR dose through WSF at 8 DI. Rice has exhibited a notably higher total uptake of N, P, and K in the treatment with 100% STCR dose through WSF at 8 DI (220.68, 44.97, and 137.41 kg N, P, and K ha-1, respectively). In fertigation with 100% RDF through WSF at 8 DI, a significantly greater seed yield (12.94 q ha-1) and haulm yield (26.17 q ha-1) of cowpea were observed. At 4 DI, 100% RDF through WSF showed a closely higher total uptake of N, P, and K by cowpea (68.94, 14.67, and 61.39 kg N, P, and K ha-1, respectively). The maximum net positive balance (148.42 kg N ha-1) was noticed in 100% RDF applied through WSF at 8 DI and minimum net positive balance 53.86 kg N ha-1 was recorded in 100% RDF-CF. During 2016-17, after the completion of second year residual crop cowpea, the maximum net positive balance (148.42 kg N ha-1) was noticed in 100% RDF applied through WSF at 8 DI and minimum net positive balance 53.86 kg N ha-1 was recorded in 100% RDF-CF. The maximum net positive balance (38.27 kg P2O5ha-1) was recorded in 100% STCR dose -WSF 8 DI and minimum net negative balance (15.70 kg P2O5 ha-1) was recorded in 100% RDF-CF. The maximum net positive balance of potassium (98.27 kg K2O ha-1) was recorded in 100% RDF-WSF 4 DI and minimum net positive balance (24.61 kg K2O ha-1) was recorded in 100% RDF-CF 8 DI treatment.

Modulating reactive oxygen species and ion homeostasis for combined salt and cadmium stress tolerance in Brassica campestris: The role of beneficial microbes

The land areas and crop species adversely impacted by salinity and heavy metals are growing rapidly. Current research indicates that plant growth-promoting microorganisms offer an environmentally friendly option for improving physiological and biochemical processes in plants growing under stress conditions. The aim of the present study was to investigate the potential mitigation of simultaneous salinity and cadmium (Cd) stress in rapeseed (Brassica campestris cv. BARI Sarisha-17) by the application of Azospirillum sp. (Az), phosphate solubilizing bacteria (PSB), potassium mobilizing bacteria (KMB), and vesicular arbuscular mycorrhiza (VAM). Seeds were treated with PSB or KMB prior to sowing, whereas Az, PSB, KMB, or VAM were added as supplements during soil preparation. At 21 days after sowing, the plants were treated with a combination of salt (100 mM NaCl) and Cd (0.25 mM CdCl2), with several applications at 7-day intervals. The combination of salt and Cd stress decreased plant growth and biomass, relative water content, and photosynthetic pigment levels, while also increased electrolyte leakage, lipid peroxidation, and the generation of excess reactive oxygen species (ROS). Salt and Cd stress also impaired plant ion balances of sodium, potassium and nitrate, antioxidant defenses, and glyoxalase system activity. Application of Az, PSB, or KMB restored these parameters to unstressed levels by facilitating the scavenging of ROS, maintaining water status, restoring ion balances, enhancing plant antioxidant defenses, and increasing glyoxalase enzyme activity, while reducing methylglyoxal toxicity and improving photosynthetic activity. The application of KMB was the most effective; however, all microbe supplementations showed the ability to alleviate the damage caused by stress in rapeseed. These findings highlight the ability of soil microorganisms with plant growth-promoting properties to improve the physiological and biochemical functions of rapeseed under Cd and salt stress.

Disorders of potassium homeostasis after kidney transplantation.

Disturbances of potassium balance are often encountered when managing kidney transplant recipients (KTR). Both hyperkalemia and hypokalemia may present either as medical emergencies or chronic outpatient abnormalities. Despite the high incidence of hyperkalemia and its potential life-threatening implications, consensus on its management in KTR is lacking. Hypokalemia in KTR is also well-described, although it is given less attention by clinicians compared to hyperkalemia. This article discusses the etiology, pathophysiology and management of both types of potassium disorders in KTR. Once any emergent situation has been corrected, treatment approaches include correcting insulin deficiency if present, adjusting non-immunosuppressive and immunosuppressive medications, eliminating or supplementing potassium as needed, and dietary counselling. Although commonly of multifactorial etiology, ascertaining the specific cause in a particular patient will help guide successful management. Monitoring KTR through regular laboratory testing is essential to detect serious disturbances in potassium balance since patients are often asymptomatic.

Substatiating the Ecological Ways of Potassium Balance Regulating in Soil

Substatiating the Ecological Ways of Potassium Balance Regulating in Soil

Iron toxicity in lowland rice influenced by application of high potassic fertilizer with suitable cultivars enhanced productivity and climate resilience

Iron poisoning in low-land rice in India develops gradually and is primarily caused by anaerobic conditions in submerged rice fields. A high concentration of ferrous ions in the soil solution disrupts the potassium balance in rice plants, leading to adverse effects on crop growth. In the 2021–2022 period, an experiment was conducted in non-saline, iron-rich soil (pH–4.82, Fe–458.6 mg kg–1) to mitigate iron toxicity in rice cultivars through potassium nutrition. The experiment involved 4 potassium application doses (K-40, K-80, K-100 and K-120) and 32 rice cultivars, replicated twice using a split-plot design. Higher potassium doses led to increased tiller counts, but gradually decreased root length. Notably, cultivars like Kanchan, Indravati, Jagabandhu, Santepheap and Salibahan exhibited the lowest iron concentration in their grains compared to susceptible cultivars. Administering K-120 resulted in a yield increase of over 36.70 q ha-1. Grain yield increased with higher K dosage, although it did not affect total iron content. However, K doses did influence specific fractions of iron in the soil. Hence, potassium nutrition appears crucial in managing iron toxicity in inceptisols, especially when paired with cultivars tolerant to iron toxicity.

Fluid and electrolyte balance following consumption of skimmed milk and a plant-based soya beverage at rest in euhydrated males

PurposeCow’s milk is one of the most hydrating beverages, but many individuals choose not to consume dairy in their diet due to intolerance, allergy, or dietary preference. Milk is commonly replaced with plant-based beverages, including soya which has the most comparable protein content, but little is known about their hydration potential. This study compared fluid and electrolyte balance responses between a soya beverage and skimmed cow’s milk.MethodsTen healthy males [age 27 (6) y; body mass index 24.6 (2.3) kg/m2] completed two randomised counterbalanced trials, involving consuming 1000 mL water from approximately isocaloric amounts of skimmed cow’s milk (MILK) or a sweetened soya beverage (SOYA), in four aliquots over 30 min in a euhydrated fasted state. Volume, specific gravity, and electrolyte (sodium, potassium, chloride) concentrations were determined in total-void urine samples collected pre-/post-beverage ingestion, and hourly for 180 min thereafter. Hunger, thirst, nausea and stomach fullness were rated proximal to urine samples.ResultsTotal urine mass (MILK, 986 ± 254 g; SOYA, 950 ± 248 g; P = 0.435) and urine specific gravity (P = 0.156) did not differ between trials. Potassium balance was greater in SOYA 0–180 min post-beverage (P ≤ 0.013), whilst chloride balance was greater in MILK 0–120 min post-beverage (P ≤ 0.036). Sodium balance (P = 0.258), total electrolyte balance (P = 0.258), and subjective measures (P ≥ 0.139) were not different between trials.ConclusionReplacing cow’s milk with a soya beverage did not negatively impact fluid balance in healthy young males, making it a viable option for those who choose not to consume dairy in their diet.

#2707 Prediction of plasma sodium changes in hypernatremic patients: the role of tissue sodium content

Abstract Background and Aims Hypo- and hypernatremia are frequently encountered electrolyte disturbances in clinical practice. Rapid correction of these dysnatremias can result in severe neurological complications. Therefore, various formulas have been developed to predict changes in plasma sodium concentration ([Na+]) after treatment. However, these kidney-centered formulas have been shown to be inaccurate. A potential explanation for the discrepancy between predicted and measured plasma [Na+] is the accumulation of sodium in the skin, which is not explicitly taken into account in these formulas. The purpose of this post-hoc analysis is to evaluate the association between factors related to tissue sodium accumulation and the discrepancy between measured and predicted plasma [Na+]. Method We used data from a hypernatremic intensive care unit (ICU) cohort with 66 patients and 1,034 ICU days with complete data on sodium, potassium and water balance. We excluded ICU days with incomplete balances, dialysis and severe diarrhea. The predicted plasma [Na+] was calculated using the Barsoum-Levine (BL) and the Nguyen-Kurtz (NK) formula. Then, we calculated the discrepancy between predicted and measured plasma [Na+] (∆[Na+]). We fitted a linear mixed-effect model to investigate the association between factors related to tissue sodium content and ∆[Na+]. Age, sex, blood pressure, eGFR, CRP, plasma albumin, total body water (TBW), baseline plasma [Na+] and changes in plasma [Na+] were incorporated as fixed effects in the model, while the subjects were introduced as a random effect. TBW was estimated as 60% of body weight for males and 50% of body weight for females, corrected for fluid balances on subsequent ICU days. Results A total of 613 ICU days of 66 patients were included in our analysis. The mean age was 58 ± 15 years and 38% was female. The mean plasma [Na+] at inclusion day was 145 ± 9 mmol/L and mean eGFR CKD-EPI was 52 ± 28 ml/min/1.73 m2. On average, the deviation between predicted and measured plasma [Na+] was 3.8 ± 3.3 mmol/L for the BL formula and 3.9 ± 3.4 mmol/L for the NK formula. For both formulas, TBW (p = 0.01), baseline plasma [Na+] (p < 0.001) and plasma [Na+] change (p < 0.001) were significantly associated with the discrepancy between predicted and measured plasma [Na+] (Table 1). Plasma albumin (p = 0.02) was also significantly associated with this discrepancy when the NK formula was used. Conclusion In a hypernatremic ICU cohort, baseline plasma [Na+], estimated TBW and plasma [Na+] changes are associated with the inaccurateness of plasma [Na+] prediction. As baseline plasma [Na+] and estimated TBW are available when initiating treatment, incorporation of these variables in the currently available formulas may improve the prediction of plasma [Na+].

Balancing sodium and potassium: Implication of mTORC2-mediated ENaC activation in DCT2 and early CNT for potassium balance in high dietary potassium

Background: The activity of the epithelial sodium ion channel, ENaC, and ENaC-dependent potassium (K+) secretion through ROMK are influenced by both aldosterone-dependent and independent mechanisms in response to dietary potassium (K+). While ENaC activity in the late connecting tubule (CNT) and cortical collecting duct (CCD) depends on aldosterone, it is aldosterone-independent in the late distal convoluted tubule (DCT2) and early CNT (eCNT). Aldosterone-stimulated ENaC activity relies on SGK1, transcriptionally upregulated by aldosterone and subsequently phosphorylated and activated by mTOR complex-2 (mTORC2). Recent evidence suggests that high potassium can rapidly activate mTORC2/SGK1 signaling to stimulate ENaC. In this study, we explore mTORC2’s role in K+ secretion and aldosterone-independent ENaC regulation. Methods: Rictor, a core component of mTORC2, was selectively knocked out (KO'd) in DCT2, CNT and CD by utilizing Calbindin as Cre-driver (CRKO mice) or late CNT and CD, by employing AQP2 as the Cre-driver (ARKO mice). Both wild-type (WT) and KO mice were subjected to a high potassium (HK) diet for short-term (4 hours) or medium-term (48 hours) periods, enabling the monitoring of both the early response and prolonged adaptation to the HK diet. Parameters assessed include urinary and blood electrolyte levels, renal transporter expression, activity and localization, and mTORC2 target phosphorylation. Results: On a normal K+ diet, both KO mice maintained Na+ and K+ balance but CRKO mice had elevated aldosterone levels. After short-term (4-hour) HK intake, CRKO mice had disrupted Na+ and K+ balance, reduced K+ excretion and hyperkalemia. In contrast, ARKO mice maintained Na+ and K+ balance with elevated aldosterone. On a prolonged HK diet (48 hours), CRKO mice had severe hyperkalemia, reduced GFR and significantly elevated aldosterone level. Immunofluorescence studies indicated markedly reduced apical localization of active ENaC in DCT2/eCNT of CRKO mice. Conversely, ENaC apical localization in the late CNT and CCD was mostly unaffected. Phosphorylation of mTORC2 targets involved in ENaC regulation, such as SGK1, and SGK1’s target, Nedd4-2, was also reduced in CRKO mice. ARKO mice maintained ion balance with normal K+ levels but significantly increased aldosterone levels and maintained ENaC apical localization in the late CNT and CCD. Conclusions: The data suggest that high aldosterone can compensate mTORC2 deficiency and maintain ENaC activity in the late CNT and CCD. However, mTORC2 activity is crucial for maintaining ENaC activity in the late DCT and early CNT (aldosterone-independent) and preserving potassium balance during high dietary potassium intake. National Institutes of Health (R01- DK56695), James Hilton Manning and Emma Austin Manning Foundation. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Оптимизиране на калиевото торене при ранно и средноранно производство на домати за устойчиви добиви и икономическа рентабилност

Split potassium fertilization is emerging as an effective technique for the prolonged assimilation of significant amounts of accessible potassium during the vegetation, with the aim of establishing a positive potassium balance in the soil and achieving increased yields of quality produce. The aim of this study was to determine the economic efficiency of the partitioning and split application of potassium doses in the cultivation of tomatoes, both in the early and mid-early production. The results showed that tomato plants demonstrate improved potassium utilization through split application, resulting in increased yields and total production revenues. Split fertilization alternatives proved to be economically viable, with N24Р12К8+8+8 approach being particularly beneficial in early tomato production. This study underlines the importance of optimizing fertilization practices in agriculture, highlighting the potential to increase economic efficiency and profitability for farmers and to ensure the sustainable use of soil resources.

Unveiling geniposide from Paederia foetida as a potential antihypertensive treatment: an integrated approach involving in vivo and computational methods

BackgroundHypertension is one of the burning topics in today’s world. Natural product can open a new window in the treatment as they are lesser side effect compared to synthetic compounds. Paederia foetida a naturally occurring plant has proven its biological importance in many aspects. In this present study, the ethanolic extract of Paederia foetida has effectively proven its antihypertensive activity against Amphetamine-induced hypertension.ResultsThe study was carried out for 4 weeks with five different groups where the groups receiving Paederia foetida (400 mg/kg) for 4 weeks result in decrease in blood pressure and was found helpful in maintaining the sodium and potassium balance in rat’s serum. Amphetamine induces decreasing sodium level that can be countered by Paederia foetida whole plant extract. Geniposide, an active ingredient present in this plant, is having antihypertensive activity, so it was docked against different PDB IDs (3OLL, 3OLS, 5DX3, 5DXE & 6PIT), to find its anti-hypertension effectiveness through computational chemistry. The docking investigations identified that estrogen receptor (PDB ID: 3OLS) exhibited the highest possibility to be the site of action. Docking score of Geniposide with 3OLS was -8.91 which is quit comparable with the internal ligand Estradiol.ConclusionTo assess the binding affinity of Geniposide with the estrogen receptor, an additional molecular dynamics simulation was conducted. The result strongly suggests that Geniposide has the potential to function as an activator of estrogen receptor through of β-ligand binding. This key finding reveals that Geniposide may serve as a potential in the treatment of hypertension by modulating the activity of the estrogen receptor.

Membrane damage by MBP-1 is mediated by pore formation and amplified by mtDNA

Eosinophils play a crucial role in host defense while also contributing to immunopathology through the release of inflammatory mediators. Characterized by distinctive cytoplasmic granules, eosinophils securely store and rapidly release various proteins exhibiting high toxicity upon extracellular release. Among these, major basic protein 1 (MBP-1) emerges as an important mediator in eosinophil function against pathogens and in eosinophil-associated diseases. While MBP-1 targets both microorganisms and host cells, its precise mechanism remains elusive. We demonstrate that formation of small pores by MBP-1 in lipid bilayers induces membrane permeabilization and disrupts potassium balance. Additionally, we reveal that mitochondrial DNA (mtDNA) present in eosinophil extracellular traps (EETs) amplifies MBP-1 toxic effects, underscoring the pivotal role of mtDNA in EETs. Furthermore, we present evidence indicating that absence of CpG methylation in mtDNA contributes to the regulation of MBP-1-mediated toxicity. Taken together, our data suggest that the mtDNA scaffold within extracellular traps promotes MBP-1 toxicity.

Land use change from paddy rice to sugarcane under long-term no-till conditions: increase P balance, soil organic matter and sugarcane productivity

ABSTRACT Expanding sugarcane (SC) cultivation at the expense of paddy rice (PRC) areas led to soil nutrient cycling changes. The study hypothesized that SC straw return and fertilizer application after land use change (LUC) from PRC to SC cropping would increase the soil-crop systems nutrient balance, ultimately enhancing growth, yield, and nutrient use efficiency of SC. In a field study involving a 17-year chronosequence of sugarcane 6 (SC6), 13 (SC13), and 17 (SC17) years after LUC, the nutrient balance dynamics of SC were monitored in comparison with those of PRC. A phosphorus (P) balance increase of 62–102% after LUC increased soil available P (Pav) from 5.2 to 13.6–16.0 mg kg−1. A potassium (K) balance decrease of 47–55% after LUC led to a decrease in soil exchangeable K (Kex) from 102.5 to 96.2–56.8 mg kg−1. Moreover, LUC increased the % sand, soil organic matter (SOM), total mineral nitrogen (N), and total N. In contrast, the % clay, bulk density, cation exchange capacity (CECpH7), and exchangeable calcium (Caex) decreased after LUC. An increase in soil nutrients increased cane yield and nutrient use efficiency with time after LUC. However, further research in different locations and management practices is required for the LUC investigation.

Conservation agriculture improves yield and potassium balance in intensive rice systems

Conservation agriculture improves yield and potassium balance in intensive rice systems

Biochemical and allelopathic features of Adonis vernalis, Allium ursinum, and Leucojum vernum in the M.M. Gryshko National Botanical Garden of the NAS of Ukraine

The article presents the results of a study on the content and dynamics of the accumulation of biogenic elements and brassinolides in plants of Adonis vernalis, Allium ursinum, and Leucojum vernum in Kyiv, Ukraine. Data is provided on allelopathic activity, content of macro- and microelements, phenolic compounds, and laccase activity in plants and the rhizosphere soil under the conditions of the M.M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine (NBG). The plants from the collection of the NBG were used as objects of study in field experiments. The content of biogenic elements in plant tissues and soil was analyzed using an inductively coupled plasma spectrometer. The allelopathic analysis of soil was conducted using a direct bioassay method with Lepidium sativum seedlings as the test object. Phenolic compounds were extracted from the soil using the ion exchange (desorption) method. The content of brassinosteroids was measured spectrophotometrically at a wavelength of 450 nm. The content of laccase was measured spectrophotometrically at a wavelength of 530 nm.The results demonstrate that model plant species employ a wide range of physiological mechanisms throughout the vegetation period to enhance their resistance to abiotic factors. These mechanisms include maintaining potassium and calcium balance and utilizing hormonal compounds. Plants have been proven to have compensatory mechanisms in response to stress factors, substituting one biochemical marker of resistance with another. Both, brassinosteroids and silicon, contribute to the adaptive capacity of organisms.

Association between sodium-to-potassium ratio in spot urine and hospitalization due to heart failure in high-risk Japanese patients

BackgroundIn Japanese cardiovascular (CV) high-risk patients, the ESPRIT (Evaluation of Sodium Intake for the Prediction of Cardiovascular Events in Japanese High-risk Patients) study showed that high sodium excretion (≥4.0 g/day) was associated with a composite CV events of heart failure (HF) hospitalization, acute coronary syndrome, cerebrovascular events, and CV deaths. In this context, the sodium-to-creatinine (Na/Cr) ratio in spot urine was found to be significantly associated with HF hospitalizations. Since a stable potassium balance plays a particularly relevant role for CV patients, this post-hoc study was designed to investigate the extent to which consideration of the sodium-to-potassium (Na/K) ratio represents a better predictor of HF hospitalizations in the ESPRIT study population. MethodsThis is a post-hoc analysis of a previously reported ESPRIT study (n = 520, 60 HF hospitalizations). ResultsReceiver operating curve analysis yielded optimal Na/K ratio cut-off value of 2.9 for detecting HF hospitalization. Kaplan–Meier curve showed that high Na/K ratio in spot urine was associated with increased HF hospitalization (p < 0.001). Cox proportional hazards model analysis revealed that high Na/K ratio was associated with HF hospitalization with a hazard ratio of 2.97 (confidence interval: 1.67–5.61). An association between high Na/K ratio and HF hospitalization remained after adjustments for Na/Cr ratio in spot urine or the use of diuretics. ConclusionThe Na/K ratio in spot urine is associated with HF hospitalization in high-risk Japanese patients.