[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-183144-105":59,"doc-detail-183144-en":123},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":116,"head_meta":118,"extra_data":120,"updated_unix":122},105,"en","quantitative-and-qualitative-characteristics-of-soil-organic-matter-under-cerrados","QUANTITATIVE AND QUALITATIVE CHARACTERISTICS OF SOIL ORGANIC MATTER UNDER CERRADOS","","Soil organic matter in Cerrados decreases with cultivation, with pronounced shifts in both quantity and composition. The carbon content is high in surface horizons and lower in subsurface horizons, then generally declines after clearing and land use. Degradation follows first-order kinetics, linking carbon losses to plant residue input and degradation rate. Fractionation indicates an increase in humin, a reduction in fulvic acids, and evidence of humic acid denaturation reflected by optical and spectroscopic changes, including 13C NMR trends.",{"@graph":69,"@context":115},[70,84,106],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/quantitative-and-qualitative-characteristics-of-soil-organic-matter-under-cerrados/183144/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/quantitative-and-qualitative-characteristics-of-soil-organic-matter-under-cerrados/183144.png","ImageObject",300,407,{"name":92,"@type":93},"Mason","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-11-02","2026-09-02",true,{"@type":102,"interactionType":103,"userInteractionCount":105},"InteractionCounter",{"@type":104},"ViewAction",14,{"@type":107,"mainEntity":108},"FAQPage",[109],{"name":110,"@type":111,"acceptedAnswer":112},"How are humic acid changes assessed and compared among soil types?","Question",{"text":113,"@type":114},"Humic acid denaturation is evaluated using optical properties (relative color intensity and color index) and classified into types based on these measures. Chemical changes are further supported by 13C NMR spectra showing decreases in aliphatic/carbohydrate carbon and increases in aromatic/carbonyl carbon.","Answer","https://schema.org",{"og:url":83,"og:type":117,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":119,"canonical":83},"index,follow",{"doc_id":121,"site_id":62},183144,1788351475,{"code":4,"msg":5,"data":124},{"doc_id":121,"user_id":125,"nickname":92,"user_avatar":126,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":127,"file_id":128,"file_url":129,"file_type":130,"file_size":131,"view_count":105,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":132,"language":133,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":134,"faqs":135,"seo_title":136,"seo_description":67,"update_tm":122,"read_time":137,"preview_page_count":4},5909887256941,"https://ap-avatar.wpscdn.com/davatar_9964176cb1d06d4a9deccf72a44ae3dc","# QUANTITATIVE AND QUALITATIVE CHARACTERISTICS OFSOIL ORGANIC MATTER UNDER CERRADOS\n\nShigemitsu Arai¹,Dimas Vital Siqueira Resck²,Alexandre Nunes Cardoso³,Nirceu Werneck Linhares⁴  \nSUMMARY-In the Cerrados,the amount of soil organic matter decreases,and the changes in its composition are considerable during cultivation.The-refore,the factors affecting the accumulation of soil organic matter should betaken into account for soil management.  \n## Objectives\n\nIn order to achieve suitable soil management,the properties of the Cer-rado soils were analysed in relation to the dynamic of organic matter in soil  \n## Working hypotheses\n\n1.The amount of soil organic matter decreases wilk soil cultivation.  \n2.Composition of soil organic matter changes,namely the amount ofeasily decomposable organic matter decreases while the resistant one increa-ses.  \n## Method\n\nComparisons were carried out between virgin soil and cultivated soil,and between Cerrado soil (LE=dark red latosol)and Terra Roxa and Lato-sol Roxo from Paraná state.Total carbon content was determined by the wetcombution method and humus composition was analysed by the methodsused in the temperate zone (Kumada et al.1976.Tatsukawa,1966.Tsutsuki&Kuwatsuka,1989).  \n## Results and Discussion\n\nI.Changes in the amount of soil organic matter during cultivation.  \nCarbon content was high in the surface horizons and low in the subsur-face horizons(Figure 1).  \nCarbon content tended to decrease during cultivation,both in the surfa-ce and subsurface horizons(Figure 2).  \nDegradation of soil organic matter and plant is considered to follow thefirst order kinetics(Jenny et al.1949,1950.Greenland &Nye 1959.Olson1963.Stanford &Smith,1972).  \nWe can consider a case where a certain amount of plant material isadded annually(Figure 3).  \nDuring this process,the carbon content is expressed by the dotted line  \nMO total=MOsoil(s)+MOplant(p),MOs=Co exp(-kn),  \nMOp=Px{exp(-k)-exp(-nk)}/{l-exp(-k)},whereCo=original soil organic C content,P=amount of plant carbon added annually,k=degradation rate constant,n =number of years.When n is sufficiently large,MOs→0,MOP/P→exp(-k)/{1-exp(-k)}(Figure 4)  \nwhen MOp/P=1,the soil carbon content is equivalent to the amount ofplant carbon added each year.The expression for calculation of plant carbonadded to the soil is shown in Apendix 1.  \nMOp is high,if k is low.When k=0.7,MOp/P=1.  \nUnder these conditions the following factors should be considered forthe accumulation of soil organic matter;  \n1.Amount of plant material added each year(P),especially roots.  \n2.Degradation rate(k),  \n(i)lignin content(especially of roots),  \n(ii)protection effect by soil components(difference among soil types),  \n(iii)degradation acceleration by nutrients from fertilizers,  \n(iv)soil temperature and moisture,  \nTOTAL CARBON(%)  \nDEPTH(cm)  \n40  \nFIG.1-Distribuition of total carbon content in virgin soils  \nTOTAL CARBON)%)  \n70  \n0  \nXO  \nTIME(years)  \nFIG.2-Carbon content changes in soils after clearing.  \nOTAL CARBON)%)  \nTIME(years)  \nFIG.3-Acumulationa of soil organic matter after addiction of plantresidues each year.  \nMOp(n→∞)  \nFIG.4-Effect of degradation rate of plant materials on carbonaccumulation.  \n3.Number of years of organic matter application (n).  \nII.Changes in the composition of soil organic matter during cultivation.  \nAfter fractionating organic matter based upon its solubilitycharacteristics(Figure 5)the following phenomena were recognized:  \nFIG.5-Flow chart of soil organic matter analysis.  \n(i)the amount of undissolved components (humin)increased(Figure 6),  \n(ii)the fulvic acid content decreased,  \nCh/Cf =0,5  \n0,4～1,1  \nFIG.6-Changes in soil organic matter composition during cultivation.  \n(iii)It is possilble that the extractability changed due to the presence ofbound-type materials(Fe,etc.bound to Al?),and  \n(iv)denaturation of humic acid.  \nDenaturation of humic acid was reflected in its optical properties(relative color intensity K600/C and color index)","cbCaim0tzCk7YwvO","https://ap.wps.com/l/cbCaim0tzCk7YwvO","pdf",1704513,11,"English","# Objectives\n## Working hypotheses\n## Method\n## Results and Discussion\n### Changes in the amount of soil organic matter during cultivation\n### Changes in the composition of soil organic matter during cultivation","[{\"question\":\"How are humic acid changes assessed and compared among soil types?\",\"answer\":\"Humic acid denaturation is evaluated using optical properties (relative color intensity and color index) and classified into types based on these measures. Chemical changes are further supported by 13C NMR spectra showing decreases in aliphatic/carbohydrate carbon and increases in aromatic/carbonyl carbon.\"}]","QUANTITATIVE AND QUALITATIVE CHARACTERISTICS OF SOIL ORGANIC MATTER UNDER CERRADOS | PDF",28]