Glauconite mineral is one of the most sensitive indicators of low sedimentation rate in the marine environment. The time of residence of glauconites at the sea bottom before burial is reflected by ...their so-called maturity that is differentiated based on their K2O content.
The present work aims to investigate the evolution of glauconites during the transition toward the highly evolved level. Complementary electron microprobe, Raman, and Thermogravimetric analysis were performed on glauconitic grains from the Belluno basin (N Italy) with different K2O content in order to verify whether the level of glauconites evolution affects the results of these surveys.
The obtained results show that Raman spectra are sensitive to the grade of glauconite maturations. First, spectra of mature glauconites are more structured, due to the lower degree of Al substitution in the octahedral sites.
Moreover, the position of the strongest Raman peak (Si–Ob–Si mode) at ∼700 cm−1 shows two contrasting behaviors in the early (K2O <8%) and late (K2O> 8%) stages of glauconites maturation, respectively. TGA measurements reveals that the presence of interlayer water is also related to the state of glauconites maturations. The obtained results were explained in the light of different isomorphic substitutions occurring at octahedral level in the mature and non-mature glauconites, thus allowing to obtain a deeper insight onto the mechanism of glauconites evolution.
•The drying were evaluated in different slice thicknesses, air velocity, and infrared power.•The total phenol content of dried eggplants were increased by 17–326%.•The potassium content of dried ...eggplants were increased by 709.1–1236.3%.•The optimal conditions were determined by response surface methodology.
The aim of this work was to study the effect of thickness of samples, air velocity and infrared power on the drying kinetics and quality attributes of blanched eggplant slices during infrared drying. The drying experiments were made by Response Surface Methodology (RSM) based on a Box–Behnken design (BBD). Experiments were conducted at a thickness of 3, 5, and 7 mm, air velocity of 0.5, 1.25, and 2 m/s, as well as at infrared power 1000, 1500, and 2000 W. The drying time was affected by operating parameters. The drying processes increased total phenolic content and potassium content, significantly. The total color difference (ΔE) was in the range of 10.22–25.14. In the end, this process was optimized for reaching the best experimental condition.
Sodium is a key element for all living things, mainly animals, some plant species, and humans. In animals, sodium ions are necessary for the regulation of blood and body fluids, the transmission of ...nerve impulses, heart activity, and certain metabolic functions. Sodium is the chief cation in the extracellular compartment of an animal body. Sodium plays a vital role not only in the human body but also in various food types. Salt, also known as sodium chloride, is about 40% sodium and 60% chloride. It flavors food and is used as a binder and stabilizer. The sodium content in different brands of edible salts can be analyzed using flame photometry. Flame photometry, also called flame atomic emission spectrometry, is a branch of atomic spectroscopy in which the species examined in the spectrometer are in the form of atoms. The samples used for analysis are junk foods, which have become a common trend among all generations. A total of 13 brands were analyzed for iodine content. From that, two commonly used brands were selected and analyzed for estimating the sodium and potassium contents in them by flame photometry. The analysis helps in creating awareness among all generations to reduce the sodium intake in order to prevent problems like hypertension, hyponatremia, hypernatremia, and associated medical complications in the future.
•AM fungi hyphae network could transport potassium to potassium deficient soil in a compartmented culture system.•Foliar-applied potassium increased biomass and photosynthesis of mycorrhizal Goji to ...promote Goji growth in the potassium-free compartment.•In AM plants, foliar-applied potassium increased potassium concentration in the potassium-free compartment by regulating the expression of genes related to potassium uptake and transport.
Arbuscular mycorrhizal (AM) fungi promote plant mineral nutrient acquisition, and AM fungal hyphae can transport water and nutrients. Potassium has significant effects on plant photosynthesis, stomatal conductance, and other physiological processes. However, it is little known whether foliar-applied potassium in one plant could affect the nearby plant that connected by the AM fungal hyphae network. We analyzed the effects of foliar-applied potassium (2% K2SO4) in the potassium additional compartment (potassium was foliar-sprayed on plant in this compartment) on growth, photosynthesis, chlorophyll fluorescence parameters, potassium content, and the relative expression of potassium channel/transporter genes (LbHAK, LbKAT3, LbAKT2, LbKT1, and LbSKOR) of mycorrhizal Lycium barbarum in the potassium-free compartment (potassium was not foliar-sprayed on plant in this compartment) via AM fungal hyphae network of a three compartments culture system (the system contains three compartments, namely two root compartments on the left and right and a hyphal compartment in the middle). Compared with inoculation of Rhizophagus irregularis, foliar-applied potassium improved growth, photosynthesis, and potassium content of mycorrhizal L. barbarum in the potassium-free compartment, but had no effect on mycorrhizal L. barbarum chlorophyll fluorescence parameters. Additionally, foliar-applied potassium increased the relative expressions of LbHAK, LbKAT3 LbKT1 and LbSKOR in roots of mycorrhizal plants in the potassium-free compartment, while the relative expression of LbAKT2 in shoots of mycorrhizal plant was increased in the potassium-free compartment. This study suggests that AM fungal hyphae network transports potassium to the potassium-free compartment, then potassium regulates the expression of potassium channel/transporter genes to promote potassium uptake and transport, thus improves photosynthesis, and ultimately, promotes the growth of mycorrhizal L. barbarum in the potassium-free compartment.
Potassium (K) is one of the most important elements influencing cotton metabolism, quality, and yield. Due to the characteristics of strong fluidity and fast redistribution of the K in plants, it ...leads to rapid transformation of the K lack or abundance in plant leaves; therefore, rapid and accurate estimation of potassium content in leaves (LKC, %) is a necessary prerequisite to solve the regulation of plant potassium. In this study, we concentrated on the LKC of cotton in different growth stages, an estimation model based on the combined characteristics of wavelet decomposition spectra and image was proposed, and discussed the potential of different combined features in accurate estimation of the LKC. We collected hyperspectral imaging data of 60 main-stem leaves at the budding, flowering, and boll setting stages of cotton, respectively. The original spectrum (R) is decomposed by continuous wavelet transform (CWT). The competitive adaptive reweighted sampling (CARS) and random frog (RF) algorithms combined with partial least squares regression (PLSR) model were used to determine the optimal decomposition scale and characteristic wavelengths at three growth stages. Based on the best “CWT spectra” model, the grayscale image databases were constructed, and the image features were extracted by using color moment and gray level co-occurrence matrix (GLCM). The results showed that the best decomposition scales of the three growth stages were CWT-1, 3, and 9. The best growth stage for estimating LKC in cotton was the boll setting stage, with the feature combination of “CWT-9 spectra + texture,” and its determination coefficients (
R
2
val) and root mean squared error (RMSEval) values were 0.90 and 0.20. Compared with the single R model (
R
2
val = 0.66, RMSEval = 0.34), the
R
2
val increased by 0.24. Different from our hypothesis, the combined feature based on “CWT spectra + color + texture” cannot significantly improve the estimation accuracy of the model, it means that the performance of the estimation model established with more feature information is not correspondingly better. Moreover, the texture features contributed more to the improvement of model performance than color features did. These results provide a reference for rapid and non-destructive monitoring of the LKC in cotton.
Plant potassium content (PKC) is a crucial indicator of crop potassium nutrient status and is vital in making informed fertilization decisions in the field. This study aims to enhance the accuracy of ...PKC estimation during key potato growth stages by using vegetation indices (VIs) and spatial structure features derived from UAV-based multispectral sensors. Specifically, the fraction of vegetation coverage (FVC), gray-level co-occurrence matrix texture, and multispectral VIs were extracted from multispectral images acquired at the potato tuber formation, tuber growth, and starch accumulation stages. Linear regression and stepwise multiple linear regression analyses were conducted to investigate how VIs, both individually and in combination with spatial structure features, affect potato PKC estimation. The findings lead to the following conclusions: (1) Estimating potato PKC using multispectral VIs is feasible but necessitates further enhancements in accuracy. (2) Augmenting VIs with either the FVC or texture features makes potato PKC estimation more accurate than when using single VIs. (3) Finally, integrating VIs with both the FVC and texture features improves the accuracy of potato PKC estimation, resulting in notable
R
2
values of 0.63, 0.84, and 0.80 for the three fertility periods, respectively, with corresponding root mean square errors of 0.44%, 0.29%, and 0.25%. Overall, these results highlight the potential of integrating canopy spectral information and spatial-structure information obtained from multispectral sensors mounted on unmanned aerial vehicles for monitoring crop growth and assessing potassium nutrient status. These findings thus have significant implications for agricultural management.
Nitrogen, phosphorus and potassium inorganic fertilizers are commonly used when growing apples, but their excessive application has resulted in a decline in soil fertility and therefore an inability ...to maintain sustainable cultivation systems. It is possible to compensate for this with biofertilizers. Nitrogen-fixing, phosphorus solubilizing, and potassium solubilizing bacteria are biofertilizers with a broad range of possible uses. In this study, beneficial microorganisms were screened from the rhizosphere soil of the apple tree, Malus sieversii (Ldb.) Roem., which is rich in microbial diversity in natural environments. It was essential to investigate their effects on the growth of apple seedlings. Eight populations of organic phosphorus solubilizing bacteria (56), inorganic phosphorus solubilizing bacteria (13), nitrogen-fixing bacteria (22), and potassium solubilizing bacteria (24) were isolated from eight populations of Xinjiang wild apple rhizosphere in Ili by medium culture. Their morphological characteristics were recorded and their activity was determined. The most active strains were Pseudomonas migulae, Pseudomonas poae, and Pseudomonas extremaustralis, which was determined by physiological and biochemical properties and 16S rDNA sequence analysis. The L16 (45) orthogonal experiment, which used the three strains as testing materials, was created to assess the effects of the strains on apple physiological indicators, soil nutrients, leaf nutrients, and biomass, as well as to identify the ideal combination, concentration, timing, and application method. The results indicated that the peroxidase (POD) and catalase (CAT) activities of apple seedlings increased significantly under the 10 treatment, and the (SOD) activities of the 0 (control) and 1 (inorganic fertilizer only) treatments were significantly lower than the other treatments; soluble sugar, soluble protein and chlorophyll contents increased in all treatments compared to 0 and 1, while malondialdehyde and proline contents increased or decreased compared to 0 and 1; apple seedlings in treatment 10 had the highest soil N, P, and K content, leaf N, P, and K content and biomass were also all highest in treatment 10. In summary, the strains screened for the test can be used as biofertilizers and the optimum application was determined for treatment 10, meaning that the results also provide a theoretical basis for their application in artificially grown orchards.
K-deficient layered manganese-based oxides P2-K0.21MnO2 and P3-K0.23MnO2 were used as cathode materials of PIBs for the first time, and they delivered high discharge capacity and outstanding capacity ...retention rate.
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Potassium-ions batteries (PIBs) are attracting increasing attention as up-and-coming youngster in large-scale grid-level energy storage benefiting from its low-cost and high energy density. Nevertheless, enough researches regarding indispensable cathode materials for PIBs are badly absent. Herein, we synthesize K-deficient layered manganese-based oxides (P2-K0.21MnO2 and P3-K0.23MnO2) and investigate them as cathode of PIBs for the first time. As the newcomer of potassium-containing layered manganese-based oxides (KxMnO2) group, P2-K0.21MnO2 delivers high discharge capacity of 99.3 mAh g−1 and P3-K0.23MnO2 exhibits remarkable capacity retention rate of 75.5%. Besides, in-situ XRD and ex-situ XRD measurements reveal the reversible phase transition of P2-K0.21MnO2 and P3-K0.23MnO2 with the potassium-ions extraction and reinsertion, respectively. This work contributes to a better understanding for the potassium storage in K-deficient layered KxMnO2 (x ≤ 0.23), possessing an important basic scientific significance for the exploitation and application of layered KxMnO2 in PIBs.
Potassium (K) is one of three main crop nutrients, and the high rate of potash fertilizer utilization (second only to nitrogen) leads to high prices. Therefore, efficient application, as well as ...rapid and time monitoring of K in crops is essential. Several turnover box and field experiments were conducted across multiple years and cultivation factors (i.e., potassium levels and plant varieties) yielding 340 groups of leaf samples with different K contents; these samples were used to examine the relationship between reflectance spectra (350–2500 nm) and leaf K content (LKC). The correlation between LKC and the two-band spectral indices computed with random two bands from 350 to 2500 nm were determined for the published K vegetation indices in rice. Results showed that the spectral reflectance, R, of the shortwave infrared (1300–2000 nm) region was sensitive to the K levels and significantly correlated with rice LKC. New shortwave infrared two-band spectral indices, Normalized difference spectral index NDSI (R
1705
, R
1385
), Ratio spectral index RSI (R
1385
, R
1705
), and Difference spectral index DSI (R
1705
, R
1385
), showed good correlations with LKC (R
2
up to 0.68). Moreover, the three-band spectral indices (R
1705
− R
700
)/(R
1385
− R
700
) and (R
1705
− R
1385
)/(R
1705
+ R
1385
− 2 × R
704
) were developed by adding red edge bands to improve accuracy. Three-band spectral indices had an improved prediction accuracy for rice LKC (R
2
up to 0.74). However, several previously published K-sensitive vegetation indices did not yield good results in this study. Validation with independent samples showed that the indices (R
1705
− R
700
)/(R
1385
− R
700
) and (R
1705
− R
1385
)/(R
1705
+ R
1385
− 2 × R
704
) had higher accuracies and stabilities than two-band indices and are suitable for quantitatively estimating rice LKC. The widescale application of these proposed vegetation indices in this paper still needs to be verified in different environmental conditions. This study provides a technical basis for LKC monitoring using spectral remote sensing in rice.
