<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Dalal, R. C.</style></author><author><style face="normal" font="default" size="100%">Harms, B. P.</style></author><author><style face="normal" font="default" size="100%">Krull, E.</style></author><author><style face="normal" font="default" size="100%">Wang, W. J.</style></author><author><style face="normal" font="default" size="100%">Mathers, N. J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Total soil organic matter and its labile pools following mulga (Acacia aneura) clearing for pasture development and cropping. 2. Total and labile nitrogen</style></title><secondary-title><style face="normal" font="default" size="100%">Australian Journal of Soil Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acetylene-reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon</style></keyword><keyword><style  face="normal" font="default" size="100%">continuous cultivation</style></keyword><keyword><style  face="normal" font="default" size="100%">delta N-15</style></keyword><keyword><style  face="normal" font="default" size="100%">ecosystems</style></keyword><keyword><style  face="normal" font="default" size="100%">fixation</style></keyword><keyword><style  face="normal" font="default" size="100%">forest</style></keyword><keyword><style  face="normal" font="default" size="100%">isotopic fractionation</style></keyword><keyword><style  face="normal" font="default" size="100%">labile N</style></keyword><keyword><style  face="normal" font="default" size="100%">long-term trends</style></keyword><keyword><style  face="normal" font="default" size="100%">mineralisable N</style></keyword><keyword><style  face="normal" font="default" size="100%">n-15 natural-abundance</style></keyword><keyword><style  face="normal" font="default" size="100%">N-2 fixation</style></keyword><keyword><style  face="normal" font="default" size="100%">soil N loss</style></keyword><keyword><style  face="normal" font="default" size="100%">southern queensland</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://000228067800008</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">43</style></volume><pages><style face="normal" font="default" size="100%">179-187</style></pages><isbn><style face="normal" font="default" size="100%">0004-9573</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mulga ( Acacia aneura) woodlands and open forests occupy about 150 Mha in Australia, and originally occupied 11.2 Mha in Queensland. Substantial areas (1.3 Mha) of the mulga vegetation have been cleared in Queensland, mostly for pasture production, but some areas are also used for cereal cropping. Twenty years after mulga clearing we found a significant loss of total soil organic C ( 28 - 35% from the 0 - 0.05 m depth) and light fraction C (&gt; 50% from the 0 - 1 m depth) from soil under pasture and cropping at a site in southern Queensland. We report here the changes in soil N and labile N pools in a paired-site study following conversion of mulga to buffel pasture (Cenchrus ciliaris) and cereal ( mostly wheat) cropping for more than 20 years. Conversion from mulga forest to pasture and cultivation resulted in greater losses of soil N than organic C in the top 0.1 m depths. As a result, C/N ratios in soil under both pasture and cropping were higher than soil under mulga, indicating a decline in soil organic matter quality after mulga clearing. Although land-use change had no significant effect on N-15 natural abundance (delta(15)N) values of total soil N down to a depth of 1m, delta(15)N values of wheat tops and roots indicated that the primary source of N under cropping was soil organic N, while that of buffel pasture was a mixed source of soil N and decomposed litter and root N. Light fraction N (&lt; 1.6 Mg/m(3)) declined by 60 - 70% throughout the 1 m soil pro. le under pasture and cropping, but it was N-15-enriched in these 2 land-use systems. The delta(15)N values of mulga phyllodes, twigs, and. ne roots, indicated an input of atmospheric fixed N-2 that was estimated to be about 25 kg N/ha. year. However, the source and magnitude of this N resource needs to be confirmed. Soil N losses were estimated to be 12 kg N/ha. year under pasture and 17 kg N/ha. year under cropping over a 20-year period. These findings raise the issue of the long-term sustainable use of cleared mulga areas for pasture and/or cropping. The labile C and N pools and N mineralised also declined, which would have an immediate adverse effect on soil fertility and plant productivity of cleared Mulga Lands, as well as reducing their potential as a soil sink for greenhouse gases.</style></abstract><work-type><style face="normal" font="default" size="100%">Article</style></work-type><accession-num><style face="normal" font="default" size="100%">ISI:000228067800008</style></accession-num><notes><style face="normal" font="default" size="100%">ISI Document Delivery No.: 912HITimes Cited: 4Cited Reference Count: 49Cited References: *DEP NAT RES MIN, 2003, LAND COV CHANG QUEEN *TECHN, 1977, 334374 WB TECHN IND ABBADIE L, 1992, ECOLOGY, V73, P608 ARANIBAR JN, 2003, J ARID ENVIRON, V54, P345, DOI 10.1006/jare.2002.1094 BEADLE NC, 1964, P LINN SOC N S W, V89, P273 BEST EK, 1976, QUEENSLAND J AGR ANI, V33, P161 BLACK AS, 1977, AUST J SOIL RES, V15, P51 BODDEY RM, 2000, NUTR CYCL AGROECOSYS, V57, P235 CHRISTENSEN BT, 1992, ADV SOIL SCI, V20, P1 CONDON RW, 1969, J SOIL CONSERVATION, V25, P47 CROOKE WM, 1971, J SCI FOOD AGR, V22, P9 DALAL RC, 1986, AUST J SOIL RES, V24, P265 DALAL RC, 1986, AUST J SOIL RES, V24, P301 DALAL RC, 1986, AUST J SOIL RES, V24, P493 DALAL RC, 1995, AUSTR J EXPT AGR, V35, P905 DALAL RC, 2005, AUST J SOIL RES, V43, P13, DOI 10.1071/SR04044 FEARNSIDE PM, 1998, FOREST ECOL MANAG, V108, P147 GATHUMBI SM, 2002, SOIL BIOL BIOCHEM, V34, P1059 GOLCHIN A, 1994, AUST J SOIL RES, V32, P1043 GREGORICH EG, 1996, STRUCTURE ORGANIC MA, P167 GRIFFIN GF, 1986, MULGA LANDS, P93 HARMS BP, 2003, 37 NCAS AUSTR GREENH ISBELL RF, 1996, AUSTR SOIL CLASSIFIC JOHNSON PA, 1994, ASTROPART PHYS, V2, P257 KEENEY DR, 1980, FOREST SCI, V26, P159 KRULL ES, 2003, GEODERMA, V112, P1 LAJTHA K, 1994, STABLE ISOTOPES ECOL, P1 LANGKAMP PJ, 1979, AUST J BOT, V27, P353 LEDGARD SF, 1988, ADV NITROGEN CYCLING, P351 MAY BM, 2003, FOREST ECOL MANAG, V181, P339, DOI 10.1016/S0378-1127(03)00006-9 MILLS JR, 1986, MULGA LANDS, P79 MONTAGNINI F, 1994, PLANT SOIL, V162, P117 MORDELET P, 1996, AUST J ECOL, V21, P336 MURTY D, 2002, GLOBAL CHANGE BIOL, V8, P105 NADELHOFFER KF, 1988, SOIL SCI SOC AM J, V52, P1633 NADELHOFFER KJ, 1994, STABLE ISOTOPES ECOL, P22 NEILL C, 1999, SOIL BIOL BIOCHEM, V31, P567 OKITO A, 2004, SOIL BIOL BIOCHEM, V36, P1179, DOI 10.1016/j.soilbio.2004.03.004 PATE JS, 1998, PLANT CELL ENVIRON, V21, P1231 PAYNE RW, 2002, GUIDE GENSTAT RELE 2 PETERSON BJ, 1987, ANNU REV ECOL SYST, V18, P293 RAISON RJ, 1987, SOIL BIOL BIOCHEM, V29, P1557 RHOADES CC, 1999, SOIL BIOL BIOCHEM, V31, P1347 ROBINSON D, 2001, TRENDS ECOL EVOL, V16, P153 SCHMIDT S, 2003, OECOLOGIA, V134, P569, DOI 10.1007/s00442-002-1150-y SHEARER G, 1974, SOIL SCI SOC AM J, V38, P315 VANBREEMEN N, 2002, NATURE, V415, P381 WILSON BA, 2002, RANGELAND J, V24, P6 YONEYAMA T, 1996, MASS SPECTROMETRY SO, P205C s i r o publishingCollingwood</style></notes></record></records></xml>