{"title":"Enhancement of alkali- and oxidation-modified biochars derived from water hyacinth for ammonium adsorption capacity","authors":"Yudai Kohira, Shinichi Akizuki, Fekremariam Asargew Mihretie, Desalew Fentie Meselu, Solomon Addisu Legesse, Shinjiro Sato","doi":"10.1080/00380768.2023.2272626","DOIUrl":"https://doi.org/10.1080/00380768.2023.2272626","url":null,"abstract":"ABSTRACTWastewater containing high concentrations of ammonium-nitrogen (NH4+-N) is considered a major concern because its untreated discharge has a variety of adverse effects on the environment and human health. Adsorption using biochars is an easy and cost-effective wastewater treatment method. However, aquatic plants such as water hyacinth for biochar feedstock are considered unsuitable for adsorbent use due to limited NH4+-N adsorption capacity. In this study, biochar made from water hyacinth was modified with potassium hydroxide (KOH) and hydrogen peroxide (H2O2) to obtain highly efficient adsorbent. This study aimed to enhance NH4+-N adsorption capacity by KOH- and H2O2-treatments and identify NH4+-N adsorption mechanism of the modified biochars derived from water hyacinth. The NH4+-N adsorption of all biochars was dependent on the initial solution pH increasing from pH 2 to 4, then relatively constant from pH 4 to 8. Pseudo-second-order model and Langmuir model were found to be the best fit for NH4+-N adsorption data. The maximum NH4+-N adsorption capacity of biochars increased about 8 times (17.1 mg g−1) and 10 times (21.5 mg g−1) after KOH- and H2O2-modification, respectively, compared to pristine biochar (2.14 mg g−1). The main NH4+-N adsorption mechanisms were suggested as cation exchange for both biochars particularly KOH-modified biochar, and hydrogen bonding by oxygen-containing surface functional groups for H2O2-modified biochar. This study suggested that aquatic plant-based biochar, which has been considered difficult to use, had potential as a promising alternative adsorbent for removing NH4+-N from wastewater through modification.KEY WORDS: Adsorption isothermadsorption kineticscarboxylic groupcation exchange capacityFTIR Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThe work was supported by the Science and Technology Research Partnership for Sustainable Development [JPMJSA2005].","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":"137 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136158676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kunihito Mihara, Kanta Kuramochi, Yo Toma, Ryusuke Hatano
{"title":"Spatiotemporal analysis of soil loss in cold climate upland farming watersheds using SWAT: case study of Tokoro River watershed, Hokkaido, Japan","authors":"Kunihito Mihara, Kanta Kuramochi, Yo Toma, Ryusuke Hatano","doi":"10.1080/00380768.2023.2264334","DOIUrl":"https://doi.org/10.1080/00380768.2023.2264334","url":null,"abstract":"ABSTRACTSevere soil erosion can cause both loss of ecosystem services and riverine environmental contaminations. Thus, understanding the spatiotemporal characteristics of soil loss at the watershed scale is critical for sustainable management of land and water resources. The primary objective of this study was to estimate the spatiotemporal variation in water runoff and soil loss in the Tokoro River watershed (TRW), Hokkaido, Japan. Assuming that agricultural land, which becomes bare depending on the season, is the main source of erosion and that large soil losses occur especially during the snowmelt/freeze-thaw period, we quantified and analyzed the mechanism of soil loss using the Soil and Water Assessment Tool 2012 (SWAT2012). Simulation results based on a publicly available dataset showed that croplands were the primary source of stream sediment load, contributing to 86% of the total soil loss. Furthermore, the soil loss rate was high (241.1–270.9 Mg km−2 yr−1) in sub-basins with a higher percentage of cropland, especially sloped croplands. These sub-basins had a higher risk of productivity loss due to intense erosion and river contamination by muddy runoff. Soil loss mainly occurred in early spring (March and April) and late summer (August – October), accounting for 36% and 45% of the annual soil loss, respectively. Vegetation removal by harvest exacerbated soil loss in October. In March, soil drainage was suppressed by frozen soil, resulting in high surface runoff and soil loss. Therefore, surface runoff when the soil was frozen was considered an important driver of soil loss. The estimation error of the stream sediment loads out of the 95% prediction uncertainty accounted for 26% of the total absolute error. This error could be attributed a lack of certainty in the observation data of high stream sediment loads and the model’s underestimation of water runoff during intense snowmelt and rainfall events.KEYWORDS: Water erosionSWAT modelfrozen groundsnowmeltagriculture AcknowledgmentsThis research was conducted with a financial support from JST SPRING (Grant Number: JPMJSP2119).Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by JST SPRING [Grant Number: JPMJSP2119].","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":"260 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135347468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Takeshi Watanabe, Kento Kato, Kohei Kawaguchi, Toshiya Oga, Yoshinori Ban, Cécile Harmonie Otoidobiga, Adama Sawadogo, Issa Wonni, Léonard S. Ouedraogo, Jean Didier Zongo, Dayéri Dianou, Susumu Asakawa
{"title":"Investigation of iron-reducing and iron-oxidizing bacterial communities in the rice rhizosphere of iron-toxic paddy field: a case study in Burkina Faso, West Africa","authors":"Takeshi Watanabe, Kento Kato, Kohei Kawaguchi, Toshiya Oga, Yoshinori Ban, Cécile Harmonie Otoidobiga, Adama Sawadogo, Issa Wonni, Léonard S. Ouedraogo, Jean Didier Zongo, Dayéri Dianou, Susumu Asakawa","doi":"10.1080/00380768.2023.2259426","DOIUrl":"https://doi.org/10.1080/00380768.2023.2259426","url":null,"abstract":"ABSTRACTIron (Fe) toxicity in rice is one of the serious problems in some paddy fields in West African areas. Microbial community structures involved in the redox cycle of Fe have not been revealed in the Fe-toxic paddy fields. The present study investigated the bacterial community structure and the abundance of Gallionellaceae, Geobacteraceae, and Anaeromyxobacteraceae, as the representative indicator bacteria of Fe oxidizers and reducers, in the bulk and rhizosphere soils and rice roots of a Fe-toxic paddy field in Burkina Faso (BF)in 2017–2019. Thosein a paddy field in Anjo, Japan (AN) were also analyzed for comparison. The amplicon sequencing analysis revealed that the BF rhizosphere soil was characterized by typical anaerobic bacterial groups like Firmicutes and Deltaproteobacteria, including several potential Fe reducers. The relative abundance of Gallionellaceae, lithotrophic Fe oxidizers, in the BF rice roots was significantly lower than that in the AN rice roots. Quantitative PCR analysis showed that the ratios of Gallionellaceae to Geobacteraceae and to Anaeromyxobacteraceae were higher in the rice roots than in the soils irrespective of the fields. However, the ratios of Gallionellaceae to Geobacteraceae were lower in the BF soils and roots than in the AN soils and roots. The ratios of Gallionellaceae to Anaeromyxobacteraceae in the BF soils were also lower than those in the AN soils. These findings indicated the relative predominance of Geobacter- and Anaeromyxobacter-related Fe reducers over Gallionellaceae-related Fe oxidizers in the rice rhizosphere of the BF field, corresponding well to the circumstances of Fe-toxic soil: higher Fe(II) amounts in the soil. Since Fe(II)-oxidizing activity at rice roots is an important factor as a primary defense system against Fe(II) in the soil solution, the ratios of Gallionellaceae to Geobacteraceae and to Anaeromyxobacteraceae may serve as an indicator of potential Fe(II)-oxidizing activity of rice rhizosphere. Further studies focusing on the activity of Fe oxidizers and Fe reducers at rice roots under effective cultivation practices and in various types of Fe-toxic paddy fields will help to promote a better understanding of the Fe-toxic soil circumstances and to establish sustainable rice cultivation in the Fe-toxic soils.KEYWORDS: Iron-oxidizing bacteriairon-reducing bacteriairon toxicitypaddy fieldrhizosphere AcknowledgmentsWe thank Kojima H. of Nagoya University for the measurement of Fed, Feo, and CEC, and Bagayogo A., Zougrana S., and Kiemde S. of the Institute of Environment and Agricultural Research for their help of the sampling and experiments in Burkina Faso.Disclosure statementNo potential conflict of interest was reported by the authors.Supplemental dataSupplemental data for this article can be accessed online at https://doi.org/10.1080/00380768.2023.2259426.Additional informationFundingThe present study was supported by the Grant-in-Aid from the JSPS KAKENHI [17H04619, 18K05372, a","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136062273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effect of slow adsorption of phosphate on its transport during the infiltration process in saturated agricultural soils","authors":"Rina Tanaka, Takehide Hama, Kimihito Nakamura, Kenji Sato, Risa Wakita","doi":"10.1080/00380768.2023.2258520","DOIUrl":"https://doi.org/10.1080/00380768.2023.2258520","url":null,"abstract":"ABSTRACTAssessment of phosphorus (P)-infiltrating croplands is essential for the preservation of the water environment. It has been pointed out that a huge discrepancy lies in the different evaluation methods of P adsorption, such as batch experiments and column experiments, which makes it difficult to demonstrate P mobility under flow conditions. The objective of this study was to evaluate the applicability of the convective-dispersion equation using the parameters of the Langmuir-type isotherm obtained from batch experiments with different reaction times: the adsorption capacity of soil (qmax) = 0.112 (g kg−1) for a Gray lowland soil with 24 h reaction time, qmax = 0.484 (g kg−1) for an Andosol (volcanic ash soil) with 24 h reaction time, and qmax = 1.17 (g kg−1) for an Andosol with 32 d reaction time, for describing P mobility in typical Japanese agricultural soils under fast flow conditions. The breakthrough curves of P infiltrating the soil columns demonstrate nonequilibrium P adsorption by the soil. The chemical nonequilibrium model, with a kinetic adsorption rate of α = 0.40 (Gray lowland soil) and 0.098 (Andosol), succeeded in describing the observations in the column experiments. Compared with Gray lowland soil, which is relatively rich in iron oxide, P mobility was largely affected by kinetic sorption in Andosol, which is relatively rich in allophane. It is suggested that the P adsorption capacity of soils should be evaluated reflecting the soil composition in order to simulate the P mobility under flow conditions. In particular, the slow adsorption (long-lasting adsorption) of P by the soil should be considered in the estimation of the P transport.KEYWORDS: Adsorption isothermAndosolGray lowland soilchemical nonequilibrium modelconvection-dispersion equation AcknowledgmentsWe thank Dr. Takeo Shima (Kyushu-Okinawa Agricultural Research Center, National Agriculture and Food Research Organization) for providing us with soil samples. This work was supported by JSPS KAKENHI (grant number JP21H02305).Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThe work was supported by the Japan Society for the Promotion of Science [JP21H02305].","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134971021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuji Suzuki, Mikuri Yamashita, Haruka Takada, Yuki Takegahara-Tamakawa, C. Miyake, A. Makino
{"title":"Effects of simultaneous Rubisco, glyceraldehyde-3-phosphate dehydrogenase, and triosephosphate isomerase overexpression on photosynthesis in rice","authors":"Yuji Suzuki, Mikuri Yamashita, Haruka Takada, Yuki Takegahara-Tamakawa, C. Miyake, A. Makino","doi":"10.1080/00380768.2023.2255213","DOIUrl":"https://doi.org/10.1080/00380768.2023.2255213","url":null,"abstract":"","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":"68 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88790489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Nishigaki, Y. Tsujimoto, Hobimiarantsoa Rakotonindrina, A. Andriamananjara
{"title":"Estimation of P retention capacity by the water content of soil kept with a saturated NaCl solution in a desiccator","authors":"T. Nishigaki, Y. Tsujimoto, Hobimiarantsoa Rakotonindrina, A. Andriamananjara","doi":"10.1080/00380768.2023.2245420","DOIUrl":"https://doi.org/10.1080/00380768.2023.2245420","url":null,"abstract":"ABSTRACT Phosphorus (P) retention capacity is an important soil parameter for site-specific nutrient management in croplands as well as a diagnostic criterion for classifying Andic properties. Air-dried soil water content is positively correlated with P retention capacity and has been proposed as a simple P retention capacity index; however, air humidity can affect the water content of air-dried soils. Therefore, in the present study, we 1) tested whether the water content of air-dried soils can be stabilized when they are kept with a saturated sodium chloride (NaCl) solution in a closed desiccator and 2) developed a model for predicting P retention capacity across various soil types. We tested 306 soil samples from paddy rice fields in Madagascar, exhibiting P retention capacities of 10.1–96.1%. Placing a saturated NaCl solution with the soil samples in a closed desiccator for one week kept the relative humidity inside the desiccator at 57–66%, regardless of the temperature and relative humidity outside the desiccator. The accuracy of the model predicting P retention capacity by soil water content was higher when soils were kept with the saturated NaCl solution [R2 = 0.870; root mean square error (RMSE) = 8.30] than without the solution (R2 = 0.812; RMSE = 9.96) at room temperature. The high correlation between P retention capacity and soil water content was mainly attributed to Al oxides. Additionally, the reproducibility of soil water content was enhanced by this method under different relative humidity conditions. However, compared with room temperature, controlling the temperature at 15°C and 30°C did not further improve the accuracy of the model when the soils were kept in the desiccator with saturated NaCl solution, although soil water content was higher at 30°C than at 15°C and room temperature. Therefore, we conclude that soil P retention capacity can be simply and accurately estimated with high reproducibility according to the water content of soils kept with saturated NaCl solution in a closed desiccator for one week at a room temperature.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":"41 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85097993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Using surface soil layer depth for determining soil quality index for evaluating productivity of potato (Solanum tuberosum L.) in Hokkaido, Japan","authors":"M. Yoshimura, Kenji Maezuka, Yo Toma","doi":"10.1080/00380768.2023.2237992","DOIUrl":"https://doi.org/10.1080/00380768.2023.2237992","url":null,"abstract":"ABSTRACT A comprehensive quantification of soil quality is necessary for data-driven soil management, and numerous studies have sought to devise methods for determining the soil quality index (SQI) to assess soil productivity. However, most studies have focused on topsoil properties rather than deeper soil properties. Therefore, this study attempted to calculate the SQI by incorporating subsoil properties and surface soil layer depth and topsoil properties, targeting farms cultivating potatoes in Tokachi region, Hokkaido. The soil parent material in this region is primarily composed of a mixture of alluvial deposits, volcanic ash, and peat, which makes the comparison between the various soil properties difficult for evaluation by farmers. Principal component analysis (PCA) and regression analysis were used to select the minimum data set (MDS) representing the variance of the original data set: exchangeable Ca, K, pH, solid phase, and acid-soluble Cu in descending order of weight. Weights were allocated based on the eigenvalues of the principal components. This study selected MDS’s parameters from properties with soil diagnosis criteria based on past research on productivity evaluation. The selected parameters contained both physical and chemical properties, which indicated that the soil quality was evaluated from both aspects. For surface soil layer depth consideration, the corrected SQI was calculated by reducing more when the depth was shallower. SQI considering subsoil properties did not correlate with yield (r = 0.358), but SQI considering surface soil layer depth was significant (r = 0.515–0.518) regardless of the soil type (parent material) and cultivar. Correlations between SQI considering depth and yield were stronger when considering a single cultivar with the greatest number of sites (r = 0.620–0.641). A deeper surface soil layer depth would provide more macropores to plant roots and improve the availability of air, greatly affecting soil quality in the Tokachi region, where precipitation is high during the growth season. Therefore, this study reveals the importance of considering the surface soil layer depth to evaluate soil productivity using the SQI.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":"17 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83202715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li Xiao, Tetsuya Yamada, Masumi Maeda, Shin-ichiro Agake, Ngoc Phuong Ngo, M. Kanekatsu, Yoshihito Shinozaki, Naoko Ohkama‐Ohtsu, T. Yokoyama
{"title":"Possible involvement of nitric oxide in promoting the initial growth of rice seedlings at low temperature by inoculation of Bacillus pumilus strain TUAT1 spores","authors":"Li Xiao, Tetsuya Yamada, Masumi Maeda, Shin-ichiro Agake, Ngoc Phuong Ngo, M. Kanekatsu, Yoshihito Shinozaki, Naoko Ohkama‐Ohtsu, T. Yokoyama","doi":"10.1080/00380768.2023.2240834","DOIUrl":"https://doi.org/10.1080/00380768.2023.2240834","url":null,"abstract":"ABSTRACT Bacillus pumilus strain TUAT1, a type of plant growth – promoting rhizobacteria (PGPR), is used as an ingredient in biofertilizer. Although we confirmed that B. pumilus TUAT1 promotes the growth of rice seedlings at 25°C, this effect has not been shown at lower temperatures. In this study, we confirmed that inoculation of rice seedlings with spores of B. pumilus TUAT1 promoted seedling emergence from soil and subsequent growth at 15°C. Except for the effect on root growth, these effects disappeared when seeds were treated with 2–4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, a nitric oxide (NO) scavenger, simultaneously with B. pumilus TUAT1 inoculation. Increased NO accumulation was detected in seed embryos 3 h after inoculation, suggesting that NO plays a role in the effects of B. pumilus TUAT1 inoculation. Transcriptome analysis using RNA-seq suggested the involvement of immune responses and cytochrome respiratory pathways in increasing NO levels in embryos after inoculation with B. pumilus TUAT1. Transcriptome analysis also indicated that transcription of genes involved in cold tolerance was accelerated in embryos following the increase in NO resulting from inoculation with B. pumilus TUAT1. These findings suggest that a novel NO signaling mechanism is involved in PGPR-induced growth promotion in plants. These results also indicate that inoculation with B. pumilus TUAT1 spores may help overcome the initial growth failure of seedlings in direct sowing culture of rice in cold regions.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":"84 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90499115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hisashi Nasukawa, R. Tajima, Maria Clarinda Filomena Pereira, Satoshi Nakamura, M. Fukuda, Kazuhiro Naruo, Tomohito Egami, T. Oya, Toyoaki Ito
{"title":"Comparative verification of Mehlich 3 soil analysis methods in Northern Mozambique using microwave plasma–atomic emission spectrometry","authors":"Hisashi Nasukawa, R. Tajima, Maria Clarinda Filomena Pereira, Satoshi Nakamura, M. Fukuda, Kazuhiro Naruo, Tomohito Egami, T. Oya, Toyoaki Ito","doi":"10.1080/00380768.2023.2238217","DOIUrl":"https://doi.org/10.1080/00380768.2023.2238217","url":null,"abstract":"ABSTRACT Regular testing of nutrients in soil samples is important for understanding soil fertility. This study investigated a combination of the Mehlich 3 extraction method and Microwave Plasma-Atomic Emission Spectrometry (MP – AES) for testing the nutrient status in soil to establish a labor-saving and cost-effective analytical method in Northern Mozambique. Available P, exchangeable cations, and micronutrients in the Mehlich 3 extract were measured using conventional methods and compared with those quantified using MP – AES to determine its accuracy. Linear regression analysis implied a high correlation between the Available P extracted via Mehlich 3 and quantified using MP – AES and that extracted via Mehlich 3, Bray 1, Olsen, and Mehlich 1 and quantified using UV – Vis. Moreover, a high determination coefficient (R2 = 0.920) was observed between Mehlich 3 quantified using MP – AES and that quantified using UV – Vis spectroscopy with a low root mean square error (RMSE = 9.245), MP – AES may have accuracy comparable to conventional methods. Linear regression of the exchangeable cations extracted using the Mehlich 3 method and quantified using MP – AES and those extracted using the 1 M NH4OAc method and quantified using ICP – AES revealed that the coefficients of determination of Ca, Mg, and K were 0.952, 0.878, and 0.826, respectively. The coefficient of determination for Na was small at 0.101. For the micronutrients, Mehlich 3 extraction with MP – AES quantification method showed a correlation with the conventional DTPA method; specifically, a strong correlation was observed for Cu and Zn. Although the correlation for Fe and Mn was also high, it was less accurate than that for the other elements. The method used in this study is considered effective for estimating field variability. To convert to conventional methods, variation in available elemental content between sites with different local soil properties should be considered.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":"41 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88398083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}