Soil Science and Plant Nutrition最新文献

{"title":"The changes in the chemical forms of thallium, cobalt and manganese with air-drying of soils","authors":"Takahiko Narukawa, T. Makino, H. Kanno, Toru Hamamoto, K. Kimura, S. Yamasaki","doi":"10.1080/00380768.2022.2095529","DOIUrl":"https://doi.org/10.1080/00380768.2022.2095529","url":null,"abstract":"ABSTRACT Thallium (Tl) is a highly toxic metal that induces pathological changes in organs. Many Tl-contaminated soils have been reported worldwide due to the releases of Tl from mineral weathering and mining industry. There is, however, limited information related to the dynamics and analysis of Tl in soil, since Tl is one of the emerging soil contaminants. Tl and cobalt (Co) are specifically adsorbed by manganese (Mn) oxide. On the other hand, air-drying of soils causes the dissolution of Mn oxide and the elution of heavy metals such as Co occluded by Mn oxide. Thus, the Mn oxide dissolution with air-drying is expected to affect the chemical forms of Tl with high sorption affinity to Mn oxide. We conducted the sequential extraction method using moist and air-dried soils. Air-drying caused the increases in Mn and Co in the exchangeable and acid soluble fractions, respectively, and the decreases in those in the Mn oxide occluded fraction, which is consistent with previous reports. Our research revealed that the exchangeable Tl increased and sum of the acid-soluble and Mn oxide occluded Tl decreased due to air-drying. The increments in the exchangeable fraction and the decrements in acid-soluble and Mn oxide occluded fractions were almost the same. Consequently, the increase in exchangeable Tl could be attributed to the other two fractions, indicating that soil Tl is sensitive to the soil drying.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77912003","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":"Nitrous oxide and carbon dioxide emissions from two soils amended with different manure composts in aerobic incubation tests","authors":"Thanuja Deepani Panangala Liyanage, M. Maeda, H. Somura, N. Thuong, M. Mori, T. Fujiwara","doi":"10.1080/00380768.2022.2095669","DOIUrl":"https://doi.org/10.1080/00380768.2022.2095669","url":null,"abstract":"ABSTRACT Identification of nitrous oxide (N2O) and carbon dioxide (CO2) emissions from soils amended with different types of compost is needed for appropriate use of manure in agriculture. This study aimed at investigating the interaction effects of compost type and soil properties and effects of moisture contents on N2O and CO2 emissions, with identification of relative abundances of functional ammonia-oxidizing genes. Laboratory tests were conducted using cattle manure compost (CC) or mixed compost (MC) (cattle, poultry, and swine manure) amended Kochi (from a greenhouse) or Ushimado (from a paddy field) soils (3% by weight) with controls (no compost). Initial moisture contents were adjusted to 60% water-holding capacity (WHC) for Kochi soil and 70% WHC for both soils. The samples were aerobically incubated at 25°C. Emissions of N2O and CO2 and contents of ammonium N (NH4 +-N) and nitrate N in soils were measured continuously until day 42. The abundances of ammonia-oxidizing bacteria (AOB) and archaea genes were estimated to evaluate nitrifying activities. Cumulative N2O and CO2 emissions were significantly higher (p < 0.05) in MC than those in CC treatments probably due to higher NH4 +-N content and lower C/N ratio, which facilitated faster N mineralization and C decomposition. Emissions of N2O and CO2 were higher in compost-amended Kochi soil (70% WHC) with high total C and N, mineral N, and clay contents than those in less fertile Ushimado soil. Interestingly, interactions of compost type and soil properties on N2O emissions were significant (p < 0.05) only in Kochi soil because the addition of decomposition resistant CC increased N2O emissions only from this soil with high C and N contents. Higher soil moisture contents increased N2O and CO2 emissions significantly (p < 0.05) in Kochi soil. Emissions of N2O until day 15 were mainly due to activities of AOB amoA genes (R2 = 0.91). This study suggests that N2O emissions are increased by high NH4 +-N contents and a low C/N ratio in compost and high total C and N, mineral N, and clay contents in soil. The application of compost with less decomposable C increases N2O emissions only from nutrient-rich soil.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73406691","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":"Organ specific transcriptome analysis of upland cotton (Gossypium hirsutum) in response to low phosphorus stress during early stage of growth","authors":"K. Lei, Jialong Cheng, Yi An, X. Li, Guoyong An","doi":"10.1080/00380768.2022.2098533","DOIUrl":"https://doi.org/10.1080/00380768.2022.2098533","url":null,"abstract":"ABSTRACT In order to systematically identify the critical genes involved in the response to low inorganic phosphorus (Pi) in cotton, we performed RNA sequencing (RNA-seq) analyses of root, stem, and leaf from Gossypium hirsutum seedlings grown under both Pi replete and Pi deplete conditions. In total, 1679, 1611, and 841 differentially expressed genes (DEGs) were observed in the roots, stems, and leaves, respectively. Several Pi-starvation-induced genes homologous to Arabidopsis were identified, such as SPX, PHO1/2, and PHF1, as well as several members of the PHT1 family, which showed different expression levels in specific organs. Subsequently, 25 randomly selected DEGs were validated by quantitative real-time PCR, the result of which was consistent with the RNA sequencing data, indicating the reliability of RNA-seq data. By analyzing the differentially expressed transcription factors, we found that the MYB family was one of the three most abundant transcription factor families in all three tissues. Moreover, some phytohormone-related DEGs were also found in G. hirsutum seedlings in this study. In particular, some auxin-responsive genes, such as IAA24, IAA11/14/16, and IAA4/14/16/29 were differentially expressed in the roots, stems and leaves of G. hirsutum seedlings respectively. Finally, homologous genes for some important phosphatases such as PPCK1 and VTC4 were also found to be differentially expressed. On analyzing the protein interaction network of 121 shared DEGs, five interaction networks – two of which contained 10 and 6 DEGs, respectively – were identified. These findings provided a theoretical basis for studying the gene function of different cotton tissues in response to low Pi stress.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84761327","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":"Application of phosphate solubilizing fungi and lime altered the soil inorganic phosphorus fractions in an Ultisol of north-eastern India","authors":"K. Alam, M. Barman, S. Datta, K. Annapurna, L. Shukla, P. Ray","doi":"10.1080/00380768.2022.2094204","DOIUrl":"https://doi.org/10.1080/00380768.2022.2094204","url":null,"abstract":"ABSTRACT The gradually dwindling reserves of rock phosphate, the primary material used in the manufacturing of phosphatic fertilizers, encourages researchers to look for ways to exploit the accumulated fixed P pool in soil. Phosphate solubilizing microorganisms (PSM) could be a viable option for addressing the problem at a lower cost. Keeping these in mind, the present study was undertaken to evaluate the changes in the distribution of P in soil as affected by P fertilization, phosphate solubilizing fungi (PSF) and liming vis-à-vis the contribution of these fractions toward P nutrition of a test crop soybean (Glycine max L.). A bulk surface soil sample (0–15 cm) was obtained from Negheriting tea estate of Golaghat district of Assam, India (Ultisol, pH = 4.23) and after processing, three levels of P [0, 50, and 100% of recommended dose of P (RDP)], two levels of lime [No lime, 1/10th of Lime Requirement (LR)] and two levels of PSF (No-PSF, PSF) were applied in a completely randomized design with three replications. Sequential P fractionation was done in the post-harvest soil. On an average, the abundance of different P fractions in the soil, expressed as % of total P, followed the order: residual P (67.5%)> Fe bound P (12.1%)> reductant soluble P (8.85%)> Al bound P (4.04%)> occluded P (3.79%)> Ca bound P (3.11%)> soluble and loosely bound P (0.46%). All the inorganic P fractions except the residual P, increased significantly with P fertilization. Either liming or PSF application significantly increased the soluble and loosely bound P fraction and decreased the Al bound and Fe bound P fractions in soil. Positive growth response of soybean was obtained due to the application of P, lime, and PSF. Liming increased the P uptake by 30.4% and dry matter yield of soybean by 18.5% over no liming. On the other hand, PSF inoculation increased the P uptake by 16.7% and dry matter yield by 7.77% over no inoculation. So, it is evident that in short term, either liming or PSF was able to solubilize the native soil P. Phosphorus×lime and lime×PSF interactions should also be exploited in future endeavors.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87208953","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":"Mapping of quantitative trait loci for root elongation in rice (Oryza sativa L.) treated with various nitrogen sources and concentrations","authors":"K. Sasaki, M. Obara","doi":"10.1080/00380768.2022.2088030","DOIUrl":"https://doi.org/10.1080/00380768.2022.2088030","url":null,"abstract":"ABSTRACT Roots are important plant organs that absorb water and nutrients. Root length responses are influenced by the plants’ sources of nitrogen (N), such as ammonium (NH4 +) and nitrate (NO3 −) ions and their concentrations. Here, to determine the genetic resources with the potential to improve the root system of rice (Oryza sativa L.), the root development traits of a core set of 334 introgression lines (ILs) were assessed in plants grown in hydroponic culture medium containing low (5 μM) or high (500 μM) concentrations of N in the form of NH4 + or NO3 −. ILs were classified into three clusters. The mean value of maximum root length (MRL) in cluster I was significantly higher than that in the other two clusters under all conditions. Root number (RN) differed significantly between clusters IIa and IIb, with the mean RN being higher in cluster IIa. In addition, the order of the mean total root length of the clusters was cluster I > IIa > IIb. Therefore, ILs in cluster I are considered genetic resources for improving root development traits under all tested N conditions. Among the ILs, YTH187 – which is derived from YP5 as a donor – had a longer MRL under all conditions. Quantitative trait loci (QTL) analyses, performed using recombinant inbred lines derived from a cross between IR 64 and YTH187, revealed that qRL5.3-YP5 and qRL6.5-YP5 were detected under all N conditions. In contrast, qRL4.1-YP5 was detected only under low KNO3 concentrations, whereas qRL8.1-YP5 was detected under high concentrations of NH4Cl and KNO3. YP5 alleles at these QTLs increased MRL. QTLs for root length in rice grown in hydroponic culture have not previously been detected in the vicinity of qRL8.1-YP5; thus, this may be a novel QTL that controls root length in rice. Moreover, qRL8.1-YP5 and qRL4.1-YP5 could be useful QTLs to determine the mechanism of root elongation under KNO3 conditions because such QTLs have not yet been detected under these conditions in rice. In future studies, further fine-mapping and characterization of qRL8.1-YP5 could reveal the mechanism of root elongation under high KNO3 concentration conditions.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91028632","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":"Different strategies for colonization and prevalence after inoculation with plant growth-promoting rhizobacteria revealed by a monitoring method","authors":"N. Gao, Huanhuan Zhang, Ruonan Xiong, L. Fang, Weishou Shen, K. Senoo","doi":"10.1080/00380768.2022.2090829","DOIUrl":"https://doi.org/10.1080/00380768.2022.2090829","url":null,"abstract":"ABSTRACT It is critical to monitor plant growth-promoting rhizobacteria (PGPR) in soils after inoculation. Among common PGPR, the Azospirillum sp. strains TSA2s and TSH100 have the ability to mitigate nitrous oxide (N2O) emissions from agricultural soils; however, their mechanism by which they successfully colonize and achieve beneficial effects in plants remains poorly understood. Here, a simple and robust procedure was developed to design strain-specific primers based on the whole-genome sequences of these two strains. After evaluating their specificity and amplification efficiency, three primer pairs were screened for each Azospirillum sp. strain. Quantification of these two strains in the rhizosphere soils of red clover revealed distinct inoculant dynamics for each strain under greenhouse conditions. Specifically, 22, 34, and 41 days after inoculation with TSA2s, the population size of the inoculant was notably greater than that in the non-inoculated control, and reached a maximum at day 34. In contrast, the population size of the TSH100 inoculant was largest at day 22, then decreased dramatically from 34 days after inoculation. These results suggest that different PGPR may have different strategies for colonization and prevalence after inoculation. Of the 31 rhizosphere carbon sources added to the Biolog Eco Micro plate to simulate plant root exudates, TSA2s utilized 14 whereas TSH100 utilized only one. TSA2s utilized more diverse root exudates of red clover, indicating better colonization and prevalence than TSH100 after inoculation. Therefore, this study presents a method of monitoring PGPR after inoculation. Furthermore, this method can screen PGPR with a better ability to survive and colonize, enabling the development of efficient, stable, and standardized biofertilizers.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79777770","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":"Nitrous oxide and carbon dioxide emissions from two types of soil amended with manure compost at different ammonium nitrogen rates","authors":"Thanuja Deepani Panangala Liyanage, M. Maeda, H. Somura, M. Mori, T. Fujiwara","doi":"10.1080/00380768.2022.2087198","DOIUrl":"https://doi.org/10.1080/00380768.2022.2087198","url":null,"abstract":"ABSTRACT Ammonium nitrogen (NH4 +-N) content in soil is a key factor affecting nitrous oxide (N2O) emissions due to its role as a primary substrate of nitrification. This study aimed at investigating the effects of different application rates of NH4 +-N on N2O and CO2 emissions from two different types of manure compost-amended soil, along with analysis of relative abundances of narG and nosZ genes under aerobic conditions. Laboratory experiments were conducted using Kochi and Ushimado soils amended with mixed compost (MC: mixture of cattle, poultry, and swine manure) or cattle manure compost (CC) at 3% (dry weight basis). In no compost- and compost-amended soils, (NH4)2SO4 was added as a solution equivalent to 160, 200, and 400 mg-N kg−1 of soil. Soil samples were aerobically incubated at 70% water-holding capacity (WHC) and 25°C. Emissions of N2O and CO2 were measured on days 0, 3, 7, 15, 21, 28, and 42. The abundances of narG and nosZ genes in Kochi (day 7) and Ushimado (day 21) soils were estimated using qPCR tests. Emissions of N2O and CO2 were higher in MC-amended soil because of higher mineral N content and lower C/N ratio of MC than those of CC, regardless of NH4 +-N rates. Emissions of N2O and CO2 were higher in compost-amended Kochi soil due to higher mineral N, total N and C, and clay contents, and possibly because of higher water-filled pore spaces than those in Ushimado soil at the same WHC. In both soils with CC and no compost, raising NH4 +-N rate from 160 to 200 increased N2O emissions due to stimulation of nitrification. In contrast, increasing NH4 +-N rate from 200 to 400 decreased N2O and CO2 emissions except for N2O emissions in MC- and CO2 emissions in CC- and no compost-amended Ushimado soil possibly due to osmotic stress on microorganisms and limited C availability. Emissions of N2O were positively related to narG gene copy numbers in Kochi soil (R 2 = 0.78) due to high N and C contents. Our study revealed that NH4 +-N rate 400 suppresses N2O and CO2 emissions from manure compost-amended soil under aerobic conditions.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76531789","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":"Changes in chemical form of phosphorus in rice bran during fermentation process as determined by 31P nuclear magnetic resonance spectroscopy","authors":"Masatoshi Ooshima, N. Yamaguchi, Y. Nakanishi, Yoshimi Hitomi, S. Hiradate","doi":"10.1080/00380768.2022.2083904","DOIUrl":"https://doi.org/10.1080/00380768.2022.2083904","url":null,"abstract":"ABSTRACT Rice bran contains appreciable amount of phosphorus (P), which can be used as P fertilizers. The efficiency of the P in the rice bran to plants, however, is low, and the fermentation of the rice bran is proposed to improve the P availability for plants. In the present study, 20 kg of rice bran was aerobically fermented by adding 5 kg of rice husk, 0.025 kg of mulch, and 7 L of water and incubating for 35 days with 6 times of stirring, and the changes in the chemical form of P during the fermentation process were investigated by 31P nuclear magnetic resonance spectroscopy and chemical extraction. Most part (84%) of P in the raw rice bran was myo-inositol-1,2,3,4,5,6-hexaphosphate (I6P), which is not available for plants. During the fermentation process, I6P was degraded and transformed into plant-available phosphate anions (orthophosphate). The proportions of the orthophosphate increased to 68% after incubating for 19 days with two times of stirring and 92% after incubating for 35 days with six times of stirring. After the fermentation, the orthophosphate was present as plant available precipitates associated with magnesium and the other monovalent cations. In conclusion, rice bran contains low-available I6P as a major P form, and the fermentation of rice bran accelerates the cleavage of the ester bond of I6P and results in the increased proportion of orthophosphate with high availability to plants.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85673490","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":"Isolation and characterization of Bradyrhizobium elkanii as a root nodule symbiont of red sword bean Canavalia gladiata var. gladiata","authors":"Wataru Masuda, Yusuke Hatanaka, A. Mochizuki, Shin Okazaki, B. Nanzai, A. Saito","doi":"10.1080/00380768.2022.2078645","DOIUrl":"https://doi.org/10.1080/00380768.2022.2078645","url":null,"abstract":"ABSTRACT Bacterial strains were isolated from root nodules of red sword bean (Canavalia gladiata var. gladiata) cultivated in Shizuoka, Japan, in order to elucidate the taxonomy of the symbionts. Of the 52 bacterial isolates, 28 strains were identified as the genus Bradyrhizobium and 10 as Rhizobium, based on the nucleotide sequences of 16S rRNA genes. Nine Bradyrhizobium isolates, which were phylogenetically selected from the 28 strains, exhibited nucleotide sequences of ITS regions that were 99.9% or 100% identical with known B. elkanii strains. These nine strains shared more than 70% similarity with B. elkanii USDA 76 T or USDA 94 in DNA-DNA hybridization analysis, indicating that the strains are B. elkanii. In a nodule formation experiment using red sword bean seeds treated with mercury chloride solution, all of the plants which were inoculated with each of the B. elkanii strains (the isolate TI06 or MI08, or the type strain USDA 76 T) formed round-type root nodules (234–664 nodules per plant), while no nodules were observed in control plants that were cultivated without inoculating bacterial strains. The bacterial strains, which were isolated from the obtained nodules, exhibited nucleotide sequences of the ITS regions that were identical to those of the corresponding inoculated strains. The root nodules formed in the experiment exhibited acetylene-reducing activity, suggesting the nitrogen-fixation activity of the nodules. We thus conclude that B. elkanii is a root nodule symbiont of red sword bean.","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84829846","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":"Preface to the special section 'Recent developments on dynamics of substances in the rhizosphere'","authors":"J. Wasaki","doi":"10.1080/00380768.2022.2088449","DOIUrl":"https://doi.org/10.1080/00380768.2022.2088449","url":null,"abstract":"The rhizosphere, as defined by Dr. Lorenz Hiltner in 1904, is recognized as the region of soil influenced by plant roots. As the interface of a plant and soil, the rhizosphere is tightly involved in nutrient dynamics. Plant roots have functions not only to uptake water and mineral nutrients but also to release a wide diversity of substances that have strong effects on nutrient availability in soils. Root-secreted compounds have important roles affecting plant–microbial interactions and symbioses, such as nodules and mycorrhiza. Although the term ‘rhizosphere’ was established as important many years ago, many difficulties particularly related to spatial and temporal constraints have hindered approaches to clarify phenomena found in the rhizosphere. Nevertheless, recent progress of analytical methods including omics analyses such as metagenomics, transcriptomics, and metabolomics have supported breakthroughs in rhizosphere research. In fact, publications including ‘rhizosphere’ as a keyword were 6.2 times more numerous in 2020 than in 2000. Recent developments of methodologies such as multiomics analyses using two or more methods of omics approaches, surface analysis, and single-cell analysis have supported great strides in elucidating rhizosphere phenomena. The first international conference on the topic of rhizospheres was held in 2004 in Munich, Germany. The rhizosphere conference has been held every 3–4 years since that first conference, with increasing attendance. Many researchers in broad fields involved in the study of rhizospheres have made important presentations at the recent conference in 2019 at Saskatoon, Canada. Interconnections among related fields including both soil and plant sides have re-emphasized the fields’ importance for further understanding. Recognition of the rhizosphere as an important topic has also been extended by the Japanese Society of Soil Science and Plant Nutrition. Soil Science and Plant Nutrition (SSPN) edited a special section ‘Frontline in the Rhizosphere Research Involved in Phosphorus: for Efficient Use of Unavailable P in Soils (Rhizo-P)’ in 2018. This Special Section, ‘Recent developments on dynamics of substances in the rhizosphere’, has been proposed to introduce current research progress in the fields. White lupin, which is well known as a cluster root forming plant species showing exudative bursts, is addressed in articles on the mineral mobilization topics. Involvement of phytohormones in the unique morphology of roots has been newly suggested in an article. Novel findings related to plant responses to nutrient deficiency and stress environments are also presented in this issue. Topics involved in the symbioses and competition between plants and microbes, and the related substances are also important. The spatial dynamics of mineral nutrients are also addressed. Research papers presented in the section were collected through announcements by the Guest Editorial Board (Dr. Jun Wasaki [chief], Dr. Takur","PeriodicalId":21852,"journal":{"name":"Soil Science and Plant Nutrition","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83891989","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}