Potash Research Articles (Page 1)

Millimeter-scale interactions of nitrogen and potassium on denitrification, anammox, and Feammox in soil fertilization zones.

Abstract Potassium (K) deficiency is a common yield‐limiting factor in cotton ( Gossypium hirsutum L.) production, requiring effective management to minimize yield losses and maintain fiber quality. We evaluated how K availability influences cotton lint yield and fiber quality. Ten fertilizer‐K rate (0–187 kg K ha −1 ) trials were conducted on silt loam soils with soil‐test K (STK) ranging from very low to above optimum during the 2023 and 2024 growing seasons. Cotton was planted in raised beds and furrow‐irrigated, and lint yield, turnout, and fiber quality (i.e., fiber length, micronaire, uniformity, strength, and elongation) were measured at maturity. Cotton lint yield was positively affected by fertilizer‐K rates ( p ≤ 0.10) at STK ≤ 114 mg K kg −1 . Yields were maximized at responsive sites with applications of 56 kg K ha −1 in long‐term trials and 37, 75, or 112 kg K ha −1 in single‐site‐year trials, showing yield increases of 20%, 53%, 47%, and 70% compared to the no‐K control, respectively. Lint turnout and fiber quality were affected by K availability. Overall, at yield‐maximizing fertilizer‐K rates, lint turnout was 2.4% greater across cultivars in relation to the control. Similarly, fiber elongation increased by 0.35%. At sites with Very Low STK, as little as 37 kg K ha −1 increased lint uniformity and strength up to 0.67% and 1.84 g tex −1 . Micronaire increased on average by 0.50, with greatest values occurring with 112 kg K ha −1 application. These findings suggest adequate K management is key to maximizing both cotton yield potential and fiber quality.

Lowland rice in humid Asian regions is prone to iron toxicity. High Fe2⁺ in the soil can reduce yield by 12–100% depending on genotype, stress severity, and soil fertility. Accordingly, two years of field experiment coined with split-plot design was conducted during the wet seasons of 2022 and 2023 at the Central Farm, Odisha University of Agriculture and Technology, Bhubaneswar. Where three replicated plots with five rice genotypes as main, while subplots received five K fertilizer levels with or without foliar kinetin (200 mg/L). Percent yield increased with both sole K application (62.42%–72.85%) and combined K with kinetin (86.39%–113.36(%), indicating that K alone was insufficient to overcome iron toxicity. Kinetin enhanced sink capacity and promoted efficient translocation of photosynthates into filled grains, improving grain weight per panicle. Increasing K doses with kinetin improved morphological traits, photosynthetic pigments, and translocation of proteins and carbohydrates from source to sink. The combined treatment alleviated Fe toxicity by limiting Fe uptake, reducing ROS, MDA, proline, and phenolics and regulating antioxidant enzyme activity. Tejaswini, treated with 100–120 kg K₂O/ha and two kinetin sprays, achieved the highest yield gains (110–113%), demonstrating its potential for sustainable rice production in iron-toxic lowlands.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-21573-7.

Nitrogen (N), phosphorus (P), and potassium (K) fertilization is widely used to enhance crop productivity. However, the synergistic effects of combined N, P, and K application on sweetpotato yield and nutrient use efficiency are not fully understood. To address this knowledge gap, a field experiment was conducted with five treatments: control (CK), no N (-N), no P (-P), no K (-K), and full NPK application (NPK). We systematically analyzed storage root yield, yield components, and nutrient accumulation characteristics. Additionally, fertilizer use efficiency and soil nutrient balance were evaluated. The NPK treatment significantly increased storage root yield by 34.8-53.1% compared with single nutrient deficiency treatments. The greatest yield reduction was observed under -P conditions, associated with low soil available P and a disordered N and K allocation ratio (5.10-14.40%). Phosphorus application resulted in high agronomic efficiency (187.79kg kg-1 P2O5) but low recovery efficiency (0.05-0.25kg kg-1 P2O5), whereas -N and -K treatments led to soil P surplus (50.25-63.06kg ha-1). A logistic model revealed that NPK treatment increased the maximum and average nutrient accumulation rates compared with deficient treatments. Pearson correlation analysis showed significant positive relationships between yield and yield components, as well as nutrient accumulation in storage roots and whole plants. Random forest regression identified P accumulation in storage roots as the most important predictor of yield. In conclusion, combined NPK fertilization enhances both storage root yield and nutrient use efficiency, with targeted P management playing a critical role in achieving high-yield and high-efficiency sweetpotato production.

The present study was conducted to investigate the effect of potassium fertilization and foliar application of chamomile extract on the growth and active compounds of Portulaca oleracea L. The experiment was carried out at the College of Medicinal and Industrial Plants / University of Kirkuk in the Ronaki area in Kirkuk Governorate using anvils. Four levels of potassium fertilizer (0, 20, 40, 80) kg K ha-1 and three concentrations of chamomile extract (0, 3, 6 g L-1 of water) were used on the growth of the portulaca plant L. oleracea. The variety used in this study is the local variety. The study was carried out with a factorial experiment and a randomized complete block design (R.C.B.D) with three replicates. The results showed that the fertilizer level of 40 kg K ha-1 was significantly superior to the rest of the levels in giving the highest plant height, number of leaves, leaf area, and other studied traits. The results also showed that the concentration (6 g L-1) of chamomile led to a significant increase in all growth characteristics of the barberry plant, while the interaction between potassium fertilization and spraying with chamomile extract had a significant effect at the combination (40 kg K ha-1 + 6 g chamomile L-1 of water) on all the studied traits.

Co-application Nitrogen and Potassium Fertilizer Enhances Nutrient Uptake and Quality of Hylocereus Undulatus by Changing Soil Properties in Karst Regions

Potassium (K) is essential for grassland productivity, but soil K leaching can reduce fertiliser use efficiency, increasing environmental losses. International evidence suggests soil type and K fertiliser timing influence K leaching, yet limited data exist for Ireland’s diverse soil types. This study investigated the effects of K fertiliser timing (autumn, winter, and spring) and soil type on K leaching using a controlled lysimeter facility with five representative Irish soils sown with perennial ryegrass. Potassium fertiliser (125 kg K ha−1) was applied in October, December, or February, with leachate collected from October to April. Soil type affected cumulative K leaching (1.4–9.8 kg ha−1; p ≤ 0.001), with the greatest losses observed in sandy soils. Potassium and nitrogen uptake in spring-harvested grass were also influenced by soil type (p ≤ 0.05), with strong positive correlation between the two nutrients (R2 = 0.78; p ≤ 0.001). Temporally, significant interactions (p ≤ 0.05) between K application timing and sampling date were found for K leachate in three of the five soils tested. Autumn and winter applications tended to increase cumulative leaching risk, especially on coarser-textured soils such as the Oakpark soil (p ≤ 0.05). The study indicates that applying K in early spring will tend to reduce leaching K losses, particularly on sandy soils.

The interaction between groundwater and surface waterplays a crucialrole in regulating water resource availability and maintaining ecosystemstability, particularly through hydrochemical exchange processes.However, at the regional scale, the driving factors governing hydrochemicalinteractions between groundwater and surface water remain inadequatelyunderstood. This study aims to identify the dominant controlling factorsand ion sources influencing hydrochemical interactions in the middleand lower reaches of the Yellow River. A comprehensive literaturereview was conducted on the hydrochemical characteristics of groundwaterand surface water across China. Ultimately, 150 representative samplingsites located in the middle and lower Yellow River Basin were selected,encompassing 28,351 groundwater samples and 15,487 surface water samples.Sampling was conducted during both the rain and dry seasons, coveringdifferent hydrological periods. Hydrochemical characteristics wereanalyzed by using a combination of hydrogeochemical statistical methods,Piper diagrams, ion ratio relationships, Gibbs plots, and PrincipalComponent Analysis (PCA). Furthermore, the Absolute Principal ComponentScores–Multiple Linear Regression (APCS-MLR) model and PHREEQCgeochemical simulations were applied to quantify the contributionsof different ion sources and assess mineral dissolution and precipitationprocesses. The results show that the main ions in groundwater andsurface water mainly come from rock weathering, evaporation, and humanactivities. The dissolution of carbonates and gypsum is the sourceof Ca2+, Mg2+ and HCO3– in groundwater and surface water. In addition, the discharge ofindustrial wastewater and domestic sewage contributed significantlyto Cl–, SO42– and Na+. The K+ and NO3– ionsmight be due to the application of nitrogen and potassium fertilizers,although contributions from other sources (e.g., sewage, natural mineraldissolution) cannot be excluded. Moreover, the PCA and APCS-MLR analysesindicated that the hydrochemical interactions between groundwaterand surface water were predominantly controlled by geological conditions(48.979%), followed by agricultural activities (16.773%), industrialinfluences (12.276%), and unidentified factors (21.972%). Among these,geological factors and mineral dissolution processes emerged as themost significant controls. Unidentified factors may include unmeasuredvariables such as atmospheric deposition, localized anthropogenicinputs, or complex groundwater–surface water exchange dynamicsnot fully captured by the model. These findings provide a comprehensiveunderstanding of the mechanisms driving groundwater–surfacewater hydrochemical interactions and offer valuable insights for regionalwater resource management, sustainable utilization, and ecologicalenvironment conservation in the Yellow River Basin.

Corn stunt complex, transmitted by the corn leafhopper (Dalbulus maidis), poses significant yield risks to corn production. This study evaluated the effects of two corn hybrids and top-dressed nitrogen (N) and potassium (K) fertilization on D. maidis incidence and corn stunt symptom expression under field conditions. Eighteen treatments were tested in a randomized complete block design with six replications over two seasons. Leafhopper populations were monitored using yellow sticky traps, and symptom incidence and severity were assessed at R1 and R3 stages, respectively. While D. maidis populations varied substantially between seasons, neither N nor K fertilization, nor hybrid selection, significantly affected vector abundance. Importantly, symptom frequency and severity were not directly proportional to leafhopper density. Top-dressed fertilization, particularly with K, reduced the visual expression of corn stunt symptoms although it did not prevent infection. Hybrid responses to fertilization varied, with a genotype exhibiting greater symptom mitigation. Grain yield was not significantly influenced by nutrient rates or hybrid choice. These findings suggest that balanced N and K fertilization enhances crop resilience to corn stunt disease without directly suppressing vector populations. Integrating nutritional management with hybrid selection presents a promising strategy to add in corn stunt control and deepens our understanding of the environmental factors that mitigate severe symptoms.

This study evaluated the effect of potassium fertilization on the physical characteristics and certain antinutritional factors (oxalates, phytates, and tannins) of two pineapple varieties (Ananas comosus L. Merr.), MD2 and smooth cayenne, cultivated in Côte d’Ivoire and stored under conditions simulating export. A randomized block experimental design was established with four increasing doses of K₂O (20, 28, 34, and 40 g/plant). The parameters measured included fruit diameter, pulp core diameter, average weight, percentage of exportable fruits, as well as oxalate, phytate, and tannin contents. Results showed that an application of 34 g K₂O/plant optimized weight, size, and percentage of exportable fruits while reducing concentrations of antinutritional compounds, particularly tannins. The MD2 variety exhibited better physical performance and lower oxalate and phytate contents compared to smooth cayenne. Beyond the optimal dose, a slight decline in performance was observed, suggesting that excess potassium may induce nutritional imbalances. These findings confirm the importance of a rational management of potassium fertilization to reconcile yield, market quality, and nutritional value, thereby strengthening the competitiveness of the Ivorian pineapple sector in export markets.

The article presents data on the effects of individual and combined applications of mineral (NPK) and organic fertilizers on the biomass of roots, stubble residues, aboveground plant parts and grain yield of amaranth cultivated in sierozem-meadow soils of the Zeravshan Valley, Uzbekistan. The field experiments followed a two-phase design. First, the impact of different nitrogen fertilizer doses (N150-300) (combined with phosphorus and potassium fertilizers-P150K200) was evaluated. Second, the study examined the effects of separate versus joint applications of chemical and organic fertilizers on amaranth productivity. The application of nitrogen fertilizers against a background of phosphorus and potassium, as well as the combined use of mineral and organic fertilizers, significantly increased the mass of root and stubble residues, aboveground biomass and grain yield in amaranth plants. These findings indicate a deficiency of mobile nutrients in the soil, which limits optimal amaranth growth. Therefore, when applying nitrogen fertilizers against the background of P150K200, complete mineral fertilizers (NPK), 30 t/ha of cattle manure and combined use of 30 t/ha of manure with different NPK rates, the yield of grain and biomass of the aboveground and underground parts of amaranth increases significantly. For example, nitrogen fertilizers at rates from 150 kg/ha to 300 kg/ha against the background of P150K200 increased the amaranth yield by 4.26-27.04 c/ha or by 46.46-94.87 c/ha. The application of complete mineral fertilizers (NPK) compared to the control without fertilizers - by 8.87-20.14 c/ha or 50.06-113.66 %, 30 t/ha of cattle manure - 14.01 c/ha or 79.06 %. The combined application of 30 t/ha of manure with different rates of mineral fertilizers increased the amaranth grain yield by 16.56-20.65 c/ha or 93.45-116.53 %. However, when the rate of nitrogen fertilizers increased from 250 kg/ha to 300 kg/ha, the amaranth yield did not increase significantly. The same pattern was observed when the rate of mineral fertilizers increased from N250P175K125 to N300P210K150. Increasing the rate of mineral fertilizers against the background of 30 t/ha of manure from N100P70K50 to N150P105K75 and to N200P140K100 did not have a significant effect on the amaranth yield. However, there was a significant difference in the amaranth yield between the N100P70K50+30 t/ha of manure and N200P140K100+30 t/ha of manure variants. The best results were obtained in the variants where 30 t/ha of manure+N200P140K100 and 250 kg/ha of nitrogen were added against the background of phosphorus and potassium fertilizers (P150K200). Thus, mineral and organic fertilizers improve the nutrition, growth and development of amaranth plants and significantly increase the biomass and grain yield of amaranth in the conditions of sierozem -meadow soils of the Zeravshan valley.

Soil is a fundamental factor influencing agricultural productivity, as it determines nutrient availability, water retention, and the long-term sustainability of farming systems. The Bareng Wonosalam District of Jombang Regency is a significant agricultural area with varied topography and intensive land use; however, comprehensive soil characterization in this region remains limited. This study aimed to analyze the physical and chemical characteristics of soils in plantation lands and classify them taxonomically to inform sustainable management. A representative plantation site in Pulosari Dua was selected using land-use and slope overlays. Five soil horizons (Ap, AB, Bt1, Bt2, BC) were described. Samples were analyzed for moisture content, texture, bulk density, pH (H₂O, KCl), electrical conductivity, organic carbon, total nitrogen, available phosphorus (Olsen, Bray), exchangeable cations (K, Na, Ca, Mg), cation exchange capacity (CEC), and base saturation (BS). Results showed moisture content of 6.2–20.8%, bulk density of 1.23–1.52 g/cm³, pH of 5.35–5.99, and organic carbon of 0.77–3.61%. Exchangeable K and Na were low (<0.60 cmol·kg⁻¹), while Ca ranged from 3.69–7.06 cmol·kg⁻¹. Textures were silty clay and clay, with BS of 53.5–117.1% and CEC of 9.15–12.93 cmol·kg⁻¹. The soils were classified as Typic Hapludalfs. Recommended practices include dolomite liming, potassium fertilization, structural amendments, and terracing. These actions are expected to enhance soil fertility, water retention, and plantation productivity by enabling targeted soil amendments, balanced nutrient application, and erosion control measures that directly address the identified limitations.

The Inner Mongolian Plateau is a critical region for the development of herbivorous animal husbandry in China. However, its harsh climate and poor soil quality have constrained the sustainable growth of the alfalfa industry. This 3-year field study investigated the effects of potassium (K) fertilizer on the productivity and forage quality of alfalfa (Medicago sativa L. cv. ‘WL168’) in such specific conditions of the region. Five rates of K fertilizer (0 (CK), 100, 200, 300, and 400 kg ha−1 of K2O) were applied in three split applications. Forage harvests occurred three times annually in 2023 and 2024, and yield, yield components, and forage quality were determined. The results showed that the forage yield of alfalfa increased initially and then decreased with the rising K application rates, which paralleled the changes in the plant density, and plant height, especially the mass shoot−1; forage yield was mainly correlated with mass shoot−1. Appropriate K fertilizer improved forage quality, especially in 2024. With increasing application, crude protein (CP) and total digestible nutrients (TDNs) first rose then declined, whereas neutral detergent fiber (NDF) and acid detergent fiber (ADF) decreased steadily, leading to a consistent rise in the relative feeding value (RFV). Comprehensively considering both yield and quality under such condition, a K fertilizer application rate of 273.2 kg ha−1 of K2O is suggested as a reference for this region.

11 years of controlled-release potassium fertilization reshaped maize ecosystems and drove sustainable soil quality: insights from physical-chemical-biological interactions.

Abstract A factorial field experiment was implemented in the 2023-2024 winter season in the Research Station of Field Crops Department, College of Agriculture, University of Anbar, to detect the influences of three potassium fertilization rates (0, 75, and 150 kg K₂O ha⁻¹) on the growth and yield of four flax cultivars: Sakha 3, Sakha 5, Sakha 6, and Geza. A randomized complete block design (RCBD) with three replications was utilized. The results indicated that Sakha 3 outperformed the other cultivars in the more of the evaluated parameters, while Sakha 5 recorded the highest mean of plant height (100.42 cm). On the other hand, Geza exhibited the highest 1000-seed weight (7.91 g). Applying of potassium at a level of 150 kg ha−¹ was significantly excelled in the plant height (101.32 cm), fruiting branches number (14.65 fruiting branch plant−1), and seeds number (9.02 seed capsule−1). While the applying of potassium at a level of 75 kg K2O ha−¹ resulted in the highest capsules number (37.72 capsule plant−1), weight of one thousand seeds (9.05 g), and yield (1.282 t ha−¹). Genetic and environmental variances were calculated, along with the genetic and phenotypic variation coefficients, and broad-sense heritability (H²). The 1000-seed weight trait demonstrated the highest genetic variation (GCV = 32.55%), phenotypic variation (PCV = 39.21%), and heritability estimate (H² = 90.11%), suggesting that it is a reliable selection criterion for enhancing flax productivity and yield potential.

Commercial citrus trees are predominantly grown in acidic soils with low boron (B) and high copper (Cu) concentrations. There are limited data on how B-Cu treatments affect the concentrations and distributions of nutrients in leaf and root subcellular fractions. Citrus sinensis seedlings were exposed to 2.5 (B2.5) or 25 (B25) μM H3BO3×0.5 (Cu0.5) or 350 (Cu350) μM CuCl2 for 24weeks. Thereafter, we assayed the concentrations of Cu, calcium, magnesium, potassium and phosphorus in leaf and root cell wall (CW) fraction, organelle fraction and soluble fraction, as well as the expression levels of genes related to their homeostasis. B25 reduced Cu350-induced damage of CW structure and function via alleviating Cu350-induced increment in the Cu concentration and decrements in the calcium, magnesium, potassium and phosphorus concentrations, as well as Cu350-induced alterations of their distributions in root and leaf subcellular fractions, thereby promoting seedling growth. Also, leaves and roots of B2.5-treated seedlings displayed some adaptive responses to Cu350. Cu350 increased the distribution of Cu in CW fraction to prevent it from entering more sensitive targets, and the distributions of calcium, magnesium and potassium in CW fraction to maintain CW structure and function. However, Cu350 decreased the distribution of phosphorus in CW fraction, but increased the release of phosphate from organic-phosphate compounds and the conversion of pyrophosphate into phosphate to maintain phosphate homeostasis. Therefore, the study provided novel evidence for B alleviating Cu toxicity in citrus via maintaining the Cu, calcium, magnesium, potassium and phosphorus homeostasis in subcellular fractions, and a scientific basis for the rational application of calcium, magnesium, potassium and phosphorus fertilizers in woody crops (citrus) to prevent Cu toxicity.

We explored how phosphorus (P) availability affects the growth and nutrient uptake of six soybean geno-types in acidic red soils in South China, with a long-term field experiment involving normal (13.68 kg·hm-2, P2O5) and low (6.84 kg·hm-2) P levels. We measured plant biomass, root traits, and mineral uptake at early flowering stage, and genotypic differences in soybean growth and the patterns of nutrient uptake. The results showed that compared with normal P level, the low P level significantly reduced biomass, total root length, and nutrient contents of all tested genotypes. Under the low P level, the average aboveground dry weight and root dry weight of soybean plants significantly decreased by 55.4% and 45.6%, the average total root length and root surface area significantly decreased by 24.8% and 29.4%, the shoot average phosphorus and potassium concentrations in plants significantly decreased by 25.6% and 9.0%, while the average iron and manganese concentrations significantly increased by 83.5% and 17.8%, respectively. However, there were no significant changes in the concentrations of nitrogen, calcium, and magnesium. Under the normal P level, plant dry weight was negatively correlated with root nitrogen, iron, and manganese concentrations. Under low P level, it was negatively correlated with aboveground iron/manganese and root manganese concentrations. We recommended that when growing soybeans in acidic low-phosphorus soils, to supplement potassium fertilizer while applying phosphorus, avoiding the toxic effects caused by excessive absorption of iron and manganese.

Maize (Zea mays L.) plays a pivotal role in global agriculture, serving as a staple food, feed and industrial crop. As the third most cultivated cereal worldwide, its productivity is influenced by a complex interplay of agronomic inputs, among which potassium (K) remains critical but often under emphasized. K is essential for several physiological functions including enzyme activation, osmoregulation and stress mitigation. Despite this, K deficiency is prevalent in many regions due to imbalanced fertilization practices and overreliance on nitrogen and phosphorus. Additionally, planting methods significantly affect K-use efficiency by modifying root architecture, moisture availability and nutrient mobility. The recent developments (2018- 2025) in potassium fertilizer technology evaluates how diverse planting techniques influence growth, yield and nutrient use efficiency in maize. Key findings suggest that integrated nutrient and planting strategies can enhance yield by up to 30% while improving K-use efficiency by 20-35%. The review concludes with future directions for research and policy to promote sustainable potassium management in maize-based systems.

This study took a close look at different types of corn plants (Zea mays L.) to see how well they stood up against the corn stem borer, Sesamia cretica. We also explored how applying potassium to the leaves affected their resistance. The experiment happened during the summer growing season of 2024 at the University of Kirkuk's Agricultural Research and Experiment Station. We used a standard experimental setup, repeating our tests three times. We tried three different potassium concentrations (0, 15, and 30 grams per liter) and tested six distinct corn varieties: KONSENS, DKC777, DKC666, AGN720, GAMESON, and GOLDEN. We measured several things: how much the plants got infected, the number of holes, larvae, and tunnels in each plant, and how much of the stem was eaten away. Our statistical analysis showed that both the potassium application and the type of corn plant, as well as their combination, had a big impact on most of the traits we measured. The only exceptions were the infection rate, the number of larvae, and the excavated distance when considering the interaction between the plant type and potassium. Interestingly, the 'GAMESON' corn variety consistently showed the best resistance. It had the lowest infection rate (15.94%), the fewest holes (5.31), larvae (1.51), tunnels (2.18), and the least stem damage (17.36%). Applying potassium at 30 grams per liter also significantly helped, reducing the infection rate to 16.38%, holes to 2.73, tunnels to 2.52, and stem damage to 16.80%. The best results came from combining the 'GAMESON' variety with the 30 gm/L potassium treatment, leading to the absolute minimum number of holes (1.86) and tunnels (1.46). This really highlights how much this combination boosts resistance. Our findings strongly suggest that using resistant corn varieties like 'GAMESON' along with smart potassium fertilization can significantly protect corn crops from the stem borer.

IntroductionThe extensive application of potassium (K) in tobacco has exacerbated the shortage of K mineral resources in China. Polyaspartic acid (PASP) had shown significant effects in promoting the absorption of K, increasing the utilization rate of K fertilizer, and improving yield and quality of tobacco.MethodsTo clarify the potential and mechanism of PASP replacing some K fertilizers in tobacco production, field experiment was conducted with 4 different treatments: NK (traditional fertilization); RT (10% reduction of K fertilizer); NKP (traditional fertilization +4% PASP/total K2O); RKP (10% reduction of K fertilizer +4% PASP/total K2O).ResultsThe reduction of K inhibited leaf growth, yield formation, K absorption, improved stem rate and decreased thickness, tensile strength, elongation rate and leaf surface density of flue-cured leaves, while had no effect on N, P, Cl content and rate of total sugar and nicotine. Comparing to NK, NKP raised the total yield by 16.7%, promoted physical properties and chemical quality optimization of flue-cured leaves. What is more, RKP compensated for the decrease in leaf yield, K content, processing utilization rate and sugar/nicotine of different parts caused by K reduction. However, K reduction and PASP application obviously influenced metabolite composition of rhizosphere soil without affecting the microbial community composition, and our results showed a relatively high correlation between differential metabolites and yield, K content, sugar/nicotine ratio, elongation rate of flue-cured tobacco.ConclusionOverall, PASP provided better optimization effects on tobacco growth, yield, physical properties, chemical quality of flue-cured leaves, and PASP was beneficial for replacing K fertilizer to a certain extent, reducing the consumption of K mineral resources and environmental pollution.