?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Foar.icrisat.org%2F2331%2F&rft.title=Physical+and+Chemical+Properties+of%0D%0A+Red+and+Black+Soils+of+Selected+Benchmark%0D%0A++Spots+for+Carbon+Sequestration+Studies+in%0D%0A++Semi-Arid+Tropics+of+India%0D%0A%3A+Global+Theme+on+Agroecosystems%0D%0A+Report+no.+35%0D%0A&rft.creator=Bhattacharyya%2C+T&rft.creator=Chandran%2C+P&rft.creator=Ray%2C+S+K&rft.creator=Mandal%2C+C&rft.creator=Pal%2C+D+K&rft.creator=Venugopalan%2C+M+V&rft.creator=Durge%2C+S+L&rft.creator=Srivastava%2C+P&rft.creator=Dubey%2C+P+N&rft.creator=Kamble%2C+G+K&rft.creator=Sharma%2C+R+P&rft.creator=Wani%2C+S+P&rft.creator=Rego%2C+T+J&rft.creator=Pathak%2C+P&rft.creator=Ramesh%2C+V&rft.creator=Manna%2C+M+C&rft.creator=Sahrawat%2C+K+L&rft.subject=Soil+Science&rft.subject=Agriculture-Farming%2C+Production%2C+Technology%2C+Economics&rft.description=Physical+(nine+characteristics)+and+chemical+(14)+properties+of+red+and+black+soils+are+described%3A+sand%2C+silt%2C+clay%2C+fine+clay%2C%0D%0A+BD%2C+COLE%2C+HC+(hydraulic+conductivity)+and+WDC%3B+pH+(H2O+and+KCl)%2C+EC%2C+OC%2C+CaCO3%2C+clay+CO3%2C+extractable+Ca%2C%0D%0A+Mg%2C+Na%2C+K%2C+CEC%2C+clay+CEC%2C+BS+and+ESP+are+described+in+three+ecosystems%2C+namely+sub-humid+(moist+and+dry)+%5BSH+(m)%0D%0A+and+SH+(d)%5D%2C+semi-arid+(moist+and+dry)+%5BSA+(m)+and+SA+(d)%5D+and+arid+in+SAT%2C+India.%0D%0A+Clay+contents+vary+between+30%25+in+arid+system+to+82%25+in+sub-humid+(dry)+system+and+79%25+in+semi-arid+(dry)+system.%0D%0A+The+red+soils+contain+8%E2%80%93-55%25+clay.+Fine+clay+(%3C0.2+%CE%BCm)+content+ranges+between+9%E2%80%9354%25+in+red+soils%3B+for+black+soils+nearly%0D%0A+50%25+of+total+clay+(%3C2+%CE%BCm)+remains+in+finer+(%3C0.2+%CE%BCm)+fractions.+The+overall+relation+between+SOC+and+BD+is+negative%3B%0D%0A+however%2C+the+correlation+between+SIC+and+BD+within+a+depth+of+0%E2%80%9330+cm+soil+depth+is+positive.+Increase+in+relative%0D%0A+proportion+of+coarse+fragments+increases+the+pore+space%2C+effecting+decrease+in+BD+values.+The+inherent+relation+between%0D%0A+total+clay+and+COLE+in+different+bioclimatic+systems+indicates+a+positive+correlation+with+a+relatively+high+value+(r+%3D+0.83)%0D%0A+in+arid+bioclimatic+system.+Except+sub-humid+(moist)+and+arid+bioclimates%2C+a+positive+correlation+between+COLE+and%0D%0A%0D%0Aslickensides+is+observed+in+most+of+the+Vertisols+in+SAT+India.+A+general+decreasing+trend+of+SOC+with+increase+in+HC%0D%0A+is+observed.+Conversely%2C+an+increasing+trend+of+HC+has+been+found+with+decrease+in+SIC.+In+all+the+bioclimates%2C+there%0D%0A+is+an+increasing+trend+of+SOC+with+decrease+in+ESP+and+an+increasing+trend+of+SIC+with+increase+in+ESP+This+is+due+to%0D%0A+preferential+release+of+Ca2%2B+ions+and+their+precipitation+as+CaCO3+in+soil%2C+thereby+increasing+the+relative+concentration%0D%0A+of+Na%2B+ions+in+the+exchange+complex+effecting+high+value+of+ESP+In+general%2C+a+positive+correlation+between+amount+of%0D%0A+fine+clay+and+SOC+in+surface+soils+has+been+found.%0D%0A+The+SOC+values+in+the+surface+(0%E2%80%9330+cm)+follow+the+trend+of+forest+system+%3E+permanent+fallow+(grassland)%2C+horticultural%0D%0A+system+%3E+agricultural+system+%3E+wasteland.+Surface+soils+of+agricultural+and+horticultural+systems+store+higher+SIC+as%0D%0A+compared+to+other+systems.+The+surface+soils+of+semi-arid+(moist)+show+higher+SOC+under+agricultural+system+due+to%0D%0A+inclusion+of+sun+hemp+for+green+manuring+in+crop+rotation.+The+average+SOC+values+follow+the+trend+of+SA+(m)+(0.825%25)%0D%0A+%3E+SH+(d)+(0.804%25)+%3E+SH+(m)+(0.642%25)+%3E+SA+(d)+(0.633%25)+%3E+arid+(0.594%25)+for+black+soils+under+agricultural+system.%0D%0A+The+values+of+SOC+follow+the+trend+of+SH+(m)+(1.35)+%3E+SA+(d)+(0.84)+%3E+SA+(m)+(0.70)+for+the+red+soils+used+for%0D%0A+cultivation.%0D%0A+The+level+of+SIC+values+in+surface+soils+under+agricultural+system+followed+the+trend+of+arid+(2.34%25)+%3E+SH+(d)+(1.06%25)%0D%0A+%3E+SA+(m)+(0.99%25)+%3E+SA+(d)+(0.94%25)+%3E+SH+(m)+(0.54%25)+for+black+soils.+In+red+soils%2C+CaCO3+in+general+is+not+found%0D%0A+except+in+soils+of+semi-arid+(dry)+bioclimatic+system.%0D%0A+The+SOC+in+surface+horizon+under+agricultural+systems+shows+higher+values+for+cereal-based+system+(0.79%25)%2C+followed%0D%0A+by+soybean+systems+(0.70%25)+and+cotton-based+systems+(0.68%25).+Interestingly%2C+the+SIC+values+have+been+found+to+be+the%0D%0A+highest+in+cotton-based+systems+(1.53%25)%2C+followed+by+soybean-based+systems+(0.66%25)+and+cereal-based+systems+(0.29%25).%0D%0A+This+trend+is+opposite+to+that+of+the+corresponding+SOC+values.%0D%0A+With+the+help+of+data+generated%2C+14+systems+(five+in+cotton%2C+three+in+soybean%2C+four+in+cereals%2C+one+in+horticulture+and%0D%0A+one+under+forest)+have+been+identified+as+ideal+for+organic+carbon+sequestration%2C+keeping+in+view+the+existing+level+of%0D%0A+management+practices+vis-%C3%A0-vis+soil+health.%0D%0A&rft.publisher=International+Crops+Research+Institute+for+the+Semi-Arid+Tropics+&rft.date=2008&rft.type=Monograph&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Foar.icrisat.org%2F2331%2F1%2F119_2007_GTAE35_phy_and_chem_prop.pdf&rft.identifier=++Bhattacharyya%2C+T+and+Chandran%2C+P+and+Ray%2C+S+K+and+Mandal%2C+C+and+Pal%2C+D+K+and+Venugopalan%2C+M+V+and+Durge%2C+S+L+and+Srivastava%2C+P+and+Dubey%2C+P+N+and+Kamble%2C+G+K+and+Sharma%2C+R+P+and+Wani%2C+S+P+and+Rego%2C+T+J+and+Pathak%2C+P+and+Ramesh%2C+V+and+Manna%2C+M+C+and+Sahrawat%2C+K+L++(2008)+Physical+and+Chemical+Properties+of+Red+and+Black+Soils+of+Selected+Benchmark+Spots+for+Carbon+Sequestration+Studies+in+Semi-Arid+Tropics+of+India+%3A+Global+Theme+on+Agroecosystems+Report+no.+35.++Monograph.+International+Crops+Research+Institute+for+the+Semi-Arid+Tropics+%2C+Patancheru%2C+Andhra+Pradesh%2C+India.+++++